Choosing The Right Crape Myrtle Tree
Crape Myrtles are shrubs and small trees that have long been associated with gardening in the South. Their resistance to drought and heat and their brilliant summer flowers make them ideal choices for easy-care gardening in hotter regions of the country. In more recent years plant breeders have developed hardier forms, making it possible for gardeners in more northern areas to grow these beautiful plants, so they are now being much more widely planted. As well, the introduction of many new colors and disease-resistant forms has widened their appeal as well as their uses.
If you are looking for a diversity of flower colors that will bloom continuously from early summer to the first frost and as well for plants that will thrive in hot, dry locations, then Crape Myrtles are ideal plants to choose and there will be a form suitable for every garden, no matter how large or small and no matter where you live. Today’s modern Crape Myrtles are available in an extraordinary range of colors and they all have long flowering seasons from mid-summer well into the fall. In addition they are available in a wide variety of sizes and forms, so they can be used in many parts of the garden, from large screens to lawn specimens and from shrub-beds to container plantings.
If you live in a suitable area it is hard to imagine gardening without Crape Myrtles. They form the main-stay of summer flowering and their spectacular foliage colors in fall as well as their attractive bark give them all-season interest. They will grow in most soils and ask only for a sunny place to grow in. They will thank you with a profusion of colors over one of the longest flowering seasons of any shrub.
What Do Crape Myrtles Look Like?
Crape Myrtles are shrubs and small trees that usually develop several trunks, although they can be pruned to a single stem. Their first notable feature is the bark, which is smooth and shows a variety of colors, ranging from grey to cinnamon and soft pink. The bark is shed in patches, which reveals new, fresh bark beneath and this shedding produces very interesting and beautiful patterns that are especially noticeable in winter or all year if plants are trained up on trunks.
The general form of the plant is bushy, often almost as wide as they are tall, but in taller varieties, they are more tree-like. The different varieties have different shapes, with some being more upright and other bushier and rounded.
The leaves are simple ovals in shape and can be between 2 and 8 inches in length depending on the variety and the vigor of growth. The leaves are glossy and dark green and in some varieties they are a rich red color in spring when they first appear, slowly fading as summer comes into dark green. In fall they turn beautiful shades of yellow, orange and red, with some varieties having richer fall color than others, but all making a great display at that special time of year.
Flower clusters appear in summer at the ends of new shoots and these panicles can be 6 to 18 inches long, again depending on the variety, the type of pruning used and the vigor of growth. The first flower clusters of the season will usually be larger than those that form later on. The flowers are about one inch across, but many are carried in each panicle, making a very dramatic effect. The petals are crinkled, like crepe-paper, which is the origin of the common name ‘Crape Myrtle’. A wide range of colors is available, in all shades from white to pink and red, as well as lilacs and purples. The only colors not available are true blues, yellows and oranges.
In warm climates flowers will appear in June and flowering will continue to at least the end of September. The flowers are followed by seed capsules about a half-inch across and these seed clusters are attractive too, especially on larger trees. As the first clusters turn to seed new side shoots are formed with new flowers, continuing the display for months and months.
Overall, Crape Myrtles are valuable plants that can be used in a variety of ways in the garden wherever a shrub or small tree is needed, with the great bonus of a fantastic flower display in many colors.
Crape Myrtles in the Garden and Landscape
The majority of people spend most of their time in the garden during summer. That is when we want to enjoy the fresh air, the warmth and the sunshine. On the hottest days the garden offers shade and coolness and invites us to sit in it. So while spring flowers are a great way to welcome the new season, summer flowering plants should form a large part of the garden plants chosen, since sitting in a summer garden surrounded by flowers is one of life’s great joys. However the list of summer-flowering trees and shrubs is not that long, so Crape Myrtles, which will reliably flower from early summer to frost, become a center-piece of the garden wherever they can be grown. With the range of sizes and colors that are available the choices are virtually endless.
The taller varieties of Crape Myrtle make excellent deciduous screening plants. Not only are they rapid-growing, deer-resistant, drought-resistant and adaptable to most soils, they will be covered all summer long in glorious blooms. Instead of an ugly view you will have beautiful flowers. They will provide visual privacy for a pool area or stop strong winds and protect more delicate plantings. To maintain a dense screen it is best to trim the plants back each winter from the first planting, so that they develop many stems and stay green to the base. Once they have reached the required size they can be trimmed lightly in late winter and they will flower all summer on new growth.
As Lawn Specimens
One of the most popular uses for Crape Myrtle is as a specimen tree or shrub in a lawn. Many other flowering trees are simply green-leaves during summer, but a Crape Myrtle makes a colorful center-piece to the lawn throughout summer. The centre of a lawn is often the sunniest place in the garden, too, so your tree will benefit from the continuous sunlight and bloom very vigorously. With such a wide range of flower colors available they can be linked to color schemes in other parts of the garden. Since this is a tree that is easily pruned without damaging its flowering, it is relatively easy to control the size and keep it within the bounds of your garden. Remember when choosing a spot for a specimen tree that you should plant it a sufficient distance from buildings for it to develop properly. You should also consider what is directly above it, particularly power and telephone lines. Many specimen trees are too tall to plant beneath lines safely, but since Crape Myrtles are relatively small they are an excellent choice as specimens for planting below power-lines and by choosing a suitable variety you can plant below even quite low lines without causing interference and potential danger.
In Shrub Borders
The summer flowering of these gorgeous plants makes them great subjects for planting among spring flowering shrubs to continue the display of flowers in your garden throughout the season. They are especially useful for planting among or behind smaller shrubs, since they will form a fresh, green backdrop when those plants are in flower and then create drama and color excitement when the early flowers are gone. Since they can be trained up on one or a few stems they can easily be planted into beds of existing plants. You may have a collection of shrubs that are nice in spring, but when summer comes there is nothing very interesting to see. Plant Crape Myrtles in among your existing shrubs, train them up a little and they will add valuable height to the display, give summer color and yet take up very little additional room. Your other plants may even appreciate the shade in summer from the hottest weather. When planting into existing beds it is important to dig a good-sized planting hole and add plenty of organic material to enrich the area, so that your new plants will become well established.
As Background Trees
In larger gardens you may already have large shade trees further away from the central part of the garden. These may form a pleasant green background, but think how much more exciting it would be to look across your garden and see trees covered in bloom. Some of the larger varieties of Crape Myrtles look wonderful planted in sunny areas in front of full-sized shade trees. Here they will need little or no pruning or other care and since they are very drought-resistant they will grow well in these kinds of areas. In a few years these colorful small trees will make beautiful focal points of color all summer long.
As Foreground Plants
It is important when planting borders of shrubs and flowers to keep the plants in the front low enough that they will not block the plants behind. Many people use flowering annuals and perennials in front of larger shrubs, but this can mean a lot of work planting and caring for them. Using small shrubs is a more modern, lower-maintenance way to fill these foreground areas, and the smaller varieties of Crape Myrtles, which only grow 3 or 4 feet tall, and can be kept even shorter by pruning, are a good choice for this job. With their colorful flowering all summer long they will brighten the garden in the same way flowers do, but with a lot less work for you. By mixing them with other smaller flowering shrubs you can create a beautiful picture in the garden without the constant replanting needed with flowers.
As Container Plants
As gardens get smaller and more and more of us live in town houses or apartments there is a growing demand for plants that will grow in pots, planter-boxes or other kinds of containers. Often these are planted with flowers that only last in summer, or need regular replacement. Wise gardeners are using dwarf shrubs instead, since once planted they will live for years. The ideal plant is one that will flower continuously during summer, when the terrace or balcony is being used most. The smaller kinds of Crape Myrtles, or for larger terraces even the medium-sized ones, are a great choice. They will be fresh and green in spring, smothered in blooms all summer and beautiful in their fall colors too. If you miss a watering they will take drought happily and they will live for years in their pots. They can be kept small and bushy, or trained up into one or a few stems to give height and interest. Crape Myrtles are one of the best shrubs for containers on hot, sunny terraces, since they love the heat and sunshine.
The History of Crape Myrtles
In 1790, shortly after the American Revolution, the French botanist André Michaux brought plants of Crape Myrtles to Charleston, South Carolina, then an important city of the historic South. Michaux grew these plants at his garden outside Charleston and from there they were distributed across the city. They thrived in the warm climate and became a powerful symbol of summer in the South.
Crape Myrtles are known to botanists as Lagerstroemia and there are around 50 wild species growing in warm regions from India and Asia to northern Australia and islands in the Pacific Ocean. They are members of the plant family called Lythraceae, which also includes Pomegranate Trees and the flowering plants called ‘loosestrife’ (Lythrum), which grows wild in damp places all across America. The plant was named by the famous botanist Carl Linnaeus to honor a Swedish fellow-countryman called Magnus von Lagerström, who supplied the botanist with exotic and new plant specimens collected on trading voyages. Although there are around 50 species in the group, only a very few are grown in gardens or have been used to develop the beautiful modern forms we grow today.
Wild Crape Myrtles usually grow in warm or tropical regions as shrubs or trees. They are typically found in forests among taller trees, in sunny clearings or on the edges of woody areas. Some species produce good lumber that can be used for anything from railway sleepers to furniture. They play an important part in the ecology of the natural forests in their homelands, providing food for insects, and one species is used in India to feed the moths that produce Tussah silk.
Important Species of Crape Myrtle
The plants that Michaux introduced and which formed the beginnings of the many varieties available today, belonged to the species Lagerstroemia indica, which grows naturally in China, Korea, Japan and India. It is usually called the Common Crape Myrtle. In the wild this plant grows into a multi-stemmed tree that is perhaps 20 feet tall. The leaves are small, oval in shape and dark green. In fall the foliage turns spectacular shades of yellow, orange and red before falling, leaving bare branches that are attractively mottled with multi-colored bark in shades of pink, cream and gray. The flowers of the wild plants are usually rosy-red to red in color.
The following species are rarely grown in gardens in their wild forms, but they have been very important in bringing desirable characteristics into the breeding programs that have produced the modern hybrid Crape Myrtles that are so widely loved today.
Lagerstroemia fauriei is known as the Japanese Crape Myrtle. This species is more tree-like than the Common Crape Myrtle, but the flowers are white, with just a few plants showing a slight pink flush in the flower. However this species is more cold-hardy and more resistant to powdery mildew than the Common Crape Myrtle, so it has been extensively used as a parent of hybrid varieties to produce plants able to grow well in colder zones.
Lagerstroemia subcostata is called the Chinese Crape Myrtle. It is a shrub or small tree and is notable particularly for its bark color, which is a brilliant burnt orange. It grows wild in the mountains of Taiwan and has white flowers with pink or purple markings.
Lagerstroemia limii is a small multi-stem tree growing to around 12 feet, which is found in hilly areas of China. The flowers are a reddish pink color. It has been used in breeding to introduce darker flower colors and shorter sizes.
Hybrid Groups of Crape Myrtles
Not content with the offerings of Nature, because of the problems of powdery mildew on these plants when grown in humid climates and to develop plants hardy in colder climates, plant breeders have turned their attention to making improvements in Crape Myrtles.
National Arboretum Crape Myrtles
The National Arboretum in Washington, D.C. has been involved for a long time in breeding many different ornamental plants, and in 1962 they turned their attention to Crape Myrtles. Dr. Donald Egolf was the skilled breeder in charge of the program and as a result of his work around 24 new varieties – botanists call them ‘cultivars’ – were released over the following years. Dr. Egolf concentrated on two main areas, improving cold hardiness and improving resistance to powdery mildew. In addition he wanted to develop forms with new flower colors and good fall leaf color, growing on plants of different heights and forms. This program was very productive and produced many varieties that are reliable plants widely grown today. The plants are usually between 10 and 20 feet in height, depending on which variety you choose and so they make ideal shrubs for the background in your garden or for specimens in the lawn.
In this breeding the common Crape Myrtle, Lagerstroemia indica, was used, but in addition rarer species, introduced especially for the breeding program, where used to provide more variety and disease resistance. The main additional species used were Lagerstroemia fauriei, Lagerstroemia subcostata, and Lagerstroemia limii, which are described above. These plants introduced hardiness, disease-resistance, different sizes and new colors into the plants. Because several species are used in this work, the resulting plants are called ‘hybrids’ and often are more vigorous and stronger than either parent, since the best qualities of each shine through, masking their weaknesses. Breeders call this ‘hybrid vigor’ and it is an important part of any breeding program.
Plant breeders take pollen from one plant and use it to fertilize the flowers of another plant, which are protected from being visited by pollinating insects so that only the pollen introduced by hand will be effective. The resulting seeds are grown and when they flower they are carefully examined and tested. Many hundreds and even many thousands of seedlings are produced in this way, but only a very few make it to the next stage. Plants which the breeders then see as interesting are allowed to grow taller to get a better idea of their qualities when they are mature. The very best of these are then propagated and send to nurseries and growers across the country to evaluate them under various local conditions of climate and soil. Based on those evaluations final selections are then made. So from many, many seedlings just a handful will make the final cut and be given names before being released officially to nurseries.
All the National Arboretum Crape Myrtles are named after tribes of Native Americans, so they are easy to recognize by their names.
These are among the very best of this group:
Arapaho Crape Myrtle
The Arapaho Crape Myrtle is a tall variety reaching around 20 feet with red flowers that are a true red, not just a dark pink. This tree has excellent resistant to powdery mildew. Its taller size makes it a great choice for background planting or for a specimen in your lawn. Although bred in 1989 this tree was not officially released until 2003, so it is still relatively uncommon in gardens.
Catawba Crape Myrtle
The Catawba Crape Myrtle, a shorter form reaching between 8 and 10 feet in height and covered all summer in flowers of a gorgeous rich purple color. It also has fall leaves in powerful orange and red tones and especially attractive grey-brown bark in winter. Additionally, It is resistant to powdery mildew and always has clean, glossy leaves. Because of its shorter height and dense growth it makes an excellent screening or informal hedge plant. This was one of Dr Egolf’s early plants which is still one of the best. It was introduced in 1967.
Muskogee Crape Myrtle
The Muskogee Crape Myrtle is the ideal choice if you want a large tree. It can reach 20 to 30 feet in height and is covered all summer with beautiful blossoms in a perfect shade of lilac. It has excellent mildew resistance and outstanding bark color, with shades of grey and soft orange predominating. The fall foliage is red and orange. This tree also has a dual use, since it is tough enough to survive winters in zone 6 with just some damage to the top growth. If it is pruned back in spring it will re-sprout and flower later in the summer on a shrub that will be 6 to 10 feet tall by the time fall comes. This hybrid was introduced in 1978.
Natchez Crape Myrtle
The Natchez Crape Myrtle is another tall Crape Myrtle, reaching 30 feet when mature. It has pure white flowers, making a very elegant show in the garden and it also has good mildew resistance. It was introduced in 1978. This variety is also notable for its spectacular bark color in cinnamon brown, an unusual shade for Crape Myrtles and showy all year round. The fall leaves are yellow, orange and orange-red in color and make a spectacular display.
Tuscarora Crape Myrtle
The Tuscarora Crape Myrtle will reach 20 feet in height and is an especially vigorous grower, forming a vase-shaped tree. It has delicious coral-pink blossoms all summer and besides its excellent mildew resistance it is also notable for the attractive red color of the new leaves in spring. The bark is mottled light-brown and the fall colors are orange and red. Although bred in 1967 it was not introduced until 1978.
Sioux Crape Myrtle
The Sioux Crape Myrtle grows between 15 and 20 feet tall and has a narrow, upright form, making it ideal for smaller gardens. The blossoms are an attractive mid-pink – a softer color than many other Crape Myrtles and the fall colors are rich shades of deep red and purple. The bark is grey-brown in color. This plant has won several medals, including Florida Plant of the Year in 1998. As would be expected it has shown good mildew resistance in trials.
Tonto Crape Myrtle
The Tonto Crape Myrtle is a recent introduction from 1995, which has flowers of a rich, fuchsia pink color and excellent mildew resistance. This multi-stem shrub grows 4 to 10 feet tall, so it is ideal for smaller gardens. The fall color is a brilliant maroon and the leaves fall to reveal cream to beige bark in winter.
Whitcomb Crape Myrtles
The National Arboretum Crape Myrtle breeding program was so successful and introduced so many wonderful plants to gardeners that the popularity of these valuable summer-flowering plants increased enormously. This led other breeders to try their hand at making improvements and Dr. Carl Whitcomb has made some very valuable introductions. Dr. Whitcomb was already a well-known and successful researcher and inventor in professional nursery growing before turning to plant breeding in the 1990’s. He worked in Oklahoma at the time and he used special laboratory techniques to encourage his Crape Myrtle plants to develop new, different genes. His work was very successful and he is responsible for the introduction of 8 terrific varieties of a second-generation of hybrid Crape Myrtles.
The most outstanding Whitcomb varieties are the following:
The Dynamite Crape Myrtle makes an explosion of red when the crimson flower buds open to show cherry-red blossoms. Even the young spring foliage is red and the plant will grow between 10 and 20 feet tall. Dr. Whitcomb was especially interested in developing Crape Myrtles for colder areas and this plant is hardy to minus 50F, making it hardy right into zone 6 and bringing Crape Myrtles into the gardens of millions more happy gardeners. Even in colder areas, although the branches will be damaged, the tree will come back after pruning to make a spectacular bush around 6 feet tall, covered in flowers from mid-summer to the arrival of frost. This tree was introduced in 1998.
The Pink Velour Crape Myrtle begins to flower with crimson buds, but they open to a clear pink which does not fade in sun or shade, as commonly happens with older varieties. This is a more compact plant, reaching around 10 feet and is multi-stemmed and shrubby. It is even hardier that ‘Dynamite’ and will survive well in all of zone 6. Even in colder regions it will readily re-sprout from the base, making a bushy 6 foot shrub and flowering well. This plant is also notable for the strong red color of its spring leaves, which stay red for several weeks and remain a dark, reddish green all summer. It also has good orange fall color. It was also introduced in 1998.
Razzle Dazzle Crape Myrtles
Over the years gardens have become smaller and even the smaller varieties of Crape Myrtles are still quite large, usually reaching 10 feet or more in time. So there was a big need for smaller plants and this became the next focus of breeding programs. Dr. Michael Dirr was already famous for his work and his name is known to every gardening student for his classic text book on trees and shrubs. He runs a breeding program at the Center for Applied Nursery Research in Dearing, Georgia, where among other plants he has turned his attention to Crape Myrtles. He was extremely successful with his breeding program and in the 2000’s he released a series of dwarf plants under the general name of Razzle Dazzle Crape Myrtles.
These plants mark a dramatic change in the form of Crape Myrtles. No longer are we looking at tall shrubs. These plants are suitable for the smallest gardens and are also excellent plants for growing in pots and containers. The summer beauty of this stunning group of plants has been brought down to a scale suitable for modern town gardens, terraces and balconies. The Razzle Dazzle Crape Myrtles are just 3 to 5 feet tall, depending on the exact variety, and about the same across, making a perfect rounded shape to completely fill a space in the garden. They are all hardy in zone 6 and will quickly regenerate from the base if there is some winter-kill of the upper branches.
Perhaps the best of this series are the following:
The Berry Dazzle Crape Myrtle grows no more than 3 or 4 feet tall and is the same across, making it a compact, bushy shrub for a small space, or to grow in a planter. The flowers are a rich fuchsia-pink and are produced all summer.
Strawberry Dazzle Crape Myrtle
The Strawberry Dazzle Crape Myrtle is a little bigger, reaching perhaps 5 feet in height and with a similar spread of 4 to 5 feet. It has bright rose-pink flowers and its slightly larger dimensions make it especially suitable for garden planting.
The Cherry Dazzle Crape Myrtle will grow to 5 feet tall and as much across in ideal growing conditions, but will also stay closer to 3 feet tall when, for example, grown in a container. It has flowers of a cherry-pink that are almost good enough to eat.
|Reference Chart to Crape Myrtles|
|Arapaho||Red||20||screening; lawn specimen; large shrub|
|Berry Dazzle||Fuchsia-pink||3-4||containers and planters; foreground shrub|
|Catawba||Purple||8-10||large shrub; small-garden lawn specimen|
|Cherry Dazzle||Cherry-pink||3-5||containers and planters; foreground and small-garden shrub|
|Dynamite*||Cherry-red||10-20||lawn specimen; large shrub; small-garden lawn specimen|
|Muskogee*||Lilac||20-30||screening; lawn specimen; background tree|
|Sioux||Medium-pink||13-20||Small-garden lawn specimen; screening; large shrub|
|Tonto*||Fuchsia-pink||4-10||large containers and planters; medium shrub|
|Natchez||White||20-30||screening; lawn specimen; background tree|
|Pink Velour*||Light-pink||10||shrub borders; foreground and small-garden shrub; large planters|
|Strawberry Dazzle||Rose-pink||4-5||foreground and small-garden shrub; large planters|
|Tuscarora||Candy-pink||20||screening; lawn specimen; large shrub|
|* – these are the most cold-hardy varieties|
Choosing the Right Crape Myrtles
Go for Disease Resistance: Older types of Crape Myrtles are prone to the disease Powdery Mildew and you may have been put off growing these plants because you have seen tired, dusty plants in mid-summer, covered with a white powder on their leaves. This disease is worst in areas that are naturally humid in summer but it occurs everywhere during periods of hot, humid weather. A lot of the breeding that has been done with Crape Myrtles has been to make plants that are resistant to this disease, so if you thought all Crape Myrtles looked like that in summer, think again! The varieties we sell are all very resistant to this disease and you will rarely if ever see it on these plants, which will look fresh and beautiful all summer long, even in humid parts of the country.
Go for Color: Crape Myrtles come in a wide range of colors, including white, lilac, and purple, many shades of pink and different shades of red. So in the garden they go well with other plants in similar colors. So they will all look great with flowers that are any shade of pink, purples from lilac to rich ports, as well as with blues. They will not look good with oranges of any shade, including fire-engine red. They will also not go with yellows that are mustardy or a bit orange, but they will go with greenish-yellows, like variegated foliage for example, or lime-green flowers and leaves.
Go for the Right Size: Decide how much room you have and how big you want your tree to grow. If you are not sure how big a plant will be, hold up a steel-tape or a pole cut to the size listed and see what it looks like. You might be surprised that what you thought would be too big looks great. Although Crape Myrtles can be pruned to control the size, it is generally best to choose a plant that will grow naturally to the size you want. Size is especially important when choosing plants for containers and boxes and this is where the Razzle Dazzle Crape Myrtles really shine, because their small size makes them ideal for container growing.
The Best Conditions for Growing Crape Myrtles
Crape Myrtles are sun-loving, drought-resistant plants. The ideal location for your plants is in full sun, although some shade will be tolerated. The amount of flowering and the length of the flowering season are directly related to how much sunshine your Crape Myrtle receives, so a sunny location is always going to be the best choice. Even a couple of hours of shade will reduce flowers a little, and the more shade the fewer flowers you will see.
If you need to plant in some shade remember that there are two kinds of shade to consider. Planting to the north of buildings often means that shade only happens during winter, when the sun is lower in the sky, so during the growing season there may well actually be sunshine on your trees. Even if there is some continuing shade, the open sky above will still allow plenty of light in, so plants can still thrive. Underneath trees is a different situation. Not only do they throw a dense shade directly over your plants, the leaves trap the very important wavelengths necessary for photosynthesis, so the light that does penetrate is of poor quality for plant growth. Shade beneath trees will also be at its greatest during summer, just when your Crape Myrtles need the most light.
So next to a building the trees will often still do well, even if flowering is a little reduced, while underneath larger trees they will usually grow very weakly with few or no flowers. If you have a shady garden there are lots of other plants, like Camellias and Azaleas, which will do well, so choose them instead.
The next thing to consider is the soil. Here Crape Myrtles are an excellent garden plant, because they are tolerant of almost all kinds of soil, including clay which often defeats other plants. If you want to know what kind of soil you have, here is an easy test:
- Put some soil in your hand and add a little water to make a paste.
- Try to roll the past out into a cylindrical shape.
- Does your cylinder fall apart immediately? Then you have a sandy soil.
- Can you make a cylinder but it breaks easily? Then you have a loam soil.
- If you can make a strong cylinder but not make it into a ring you have a silt soil.
- If you can make a ring you have a clay soil.
This test will not give you perfect results, but it will give you a good indication of the soil you are dealing with.
Crape Myrtles do best in loam, silt or clay soils, provided they are not always wet. They will grow well in almost any soil and in fact very rich soils, or giving them too much compost or fertilizer, will make lots of healthy leaves but fewer flowers. Their ability to thrive in poorer soil makes them great plants for difficult locations and even spots with only a limited amount of soil. You will often see beautiful Crape Myrtles growing in small pockets of dry soil along roadways or in parking lots.
Although Crape Myrtles grow best in slightly acidic soil, they will grow well in most soils except for very alkaline ones. If you see pale yellow new leaves and you know you have alkaline soil, treat your plant by watering with Chelated Iron, which is available from garden centres. Simple and cheap tests are available at garden centres to find out if your soil is acid or alkaline.
Crape Myrtles are plants from warmer regions, so they grow best in the warmer areas of America, in zones 7, 8 and 9. So from Virginia across to Oklahoma and everywhere south, as well as all up the West Coast, they will thrive. For a long time gardeners in more northern regions could only admire the Crape Myrtles when visiting the south, but with modern varieties it is now possible to grow them in zone 6 and even into zone 5. Some branches will be killed in winter, but new shoots will come in spring from lower down on the stems or even right from the base of the plant. This means that across most of the country you can enjoy these beautiful summer flowers.
Since Crape Myrtles flower on new shoots they can be just as prolific flowering in colder areas, but they will stay smaller than the sizes listed for them. For example the Dynamite Crape Myrtle will grow up to 20 feet in a warm region, but rarely reach more than 6 feet in colder areas. The Pink Velour Crape Myrtle will be 10 feet in warm areas, but only 5 or 6 feet tall in colder regions. These two varieties were especially produced for colder climates and are the number one choice for Crape Myrtles if you live in zone 6 or warmer parts of zone 5. The Muskogee Crape Myrtle is another variety that is hardy and will re-sprout and flower well, while staying much smaller than its normal size.
In colder areas it is especially important to plant in sheltered locations that get sun all day long. Because Crape Myrtles need warmth to flower well they must be in very hot positions in colder areas to create a good ‘microclimate’ for their growth. They will usually flower mostly in late summer and fall when grown in colder regions, which is great, because that is a time when there is very little else in bloom.
Choosing a Planting Location
Once you plant your Crape Myrtle, you probably don’t want to start moving it again. So it is worth taking some time to carefully decide where to place it. Your first consideration should be that there is enough sunshine. Remember that the ground could be shady, but 10 feet in the air it may be sunny, which is where your tree will be – and sometimes this is true in reverse.
The second major consideration is to make sure that there is room for it to grow. Many trees and shrubs never get a chance to show their true beauty because they are squeezed into a tiny space and crowded by other plants. Equally you don’t want your new plant to crowd out plants around it, so allow enough room for everyone. The small and medium-sized Crape Myrtles are almost as wide as they are high and the taller ones are about two-thirds of their height in width. Just as important is to consider the final height. Is there something overhead – power-lines, the overhang of a building, or the branches of a tree, that is going to interfere with your new Crape Myrtle? If you really want it in that spot, maybe you can prune it a little to make it fit, but it is always better to have enough room for the natural development of your tree. Keep you plant at least 6 feet from a swimming pool and 12 feet from a septic bed, so that roots do not cause any damage.
When planting your Crape Myrtles in rows or groups it is important to space them correctly. If they are too close they will not develop well, but if they are too far apart they may take years to meet, or even always stay separated. The ideal spacing will allow the plants to grow, yet mean that in a few years they will form a single mass of plants.
For a screen, there are two methods of spacing and planting available.
- Single row: this is the most obvious method and here you should place the plants between 4 and 8 feet apart, depending on their final size and your needs. The tallest varieties should be spaced 6 or even 8 feet apart, while shorter tree forms, those under 20 feet tall, should go 4 to 6 feet apart. Wider spacing will obviously take longer to fill in, but you will need fewer trees. If your screen is against a building, plant 6 feet from the wall, to protect the foundations. If you are planting against a fence, plant 3 feet from the fence so that the lower part of the plants remains bushy.
- Double row: This method will give a quicker screen and use slightly fewer plants for the density of screen created. Make a double row, allowing 3 feet between the rows. Space the plants 6 to 8 feet apart for varieties 20 feet tall or less and 8 to 10 feet apart for taller varieties. Stagger the plants so each one is in the space of the other row. This method will give a good dense screen in a short time.
To calculate how many plants you need for a screen, first measure the distance. Then decide on the spacing. Divide the distance by the spacing and round-up to the next number if the answer is a fraction. For a double row multiply this number by 2. Remember that the first plant will be placed half the spacing distance from the end of the row, and the last plant will be placed in the same way. Then balance out the remaining plants in between at even distances.
Remember that whatever spacing you use it is important to keep everything at the same distance and place everything very evenly. Use a measuring tape to get everything laid-out before planting. The extra work will be worth it when you see the perfect screen you have created.
If you want your screen right to the ground it is important to trim the branches each spring quite hard to develop lots of stems close to the ground. If you let the plants grow untrimmed until they are the height you want they will be thin lower down and may not give you the screening you want to develop.
Planting in groups is a great way to work with smaller and medium-sized varieties. Always plant your shrubs using odd numbers, 3, 5, 7, 9, 11, etc. This will give your planting a more natural look. Smaller varieties tend to be as wide as they are across, so just deduct 1 foot from the height for small plants like the Razzle Dazzle Crape Myrtles, and 2 feet from the height of medium-sized varieties. Place your plants at those distances apart and in a few years they will have grown together into a single mass. When you are planting larger groupings, avoid making rows and try to scatter the plants over the area in a more random way as you fill the area you have available
Planting Crape Myrtles
Although Crape Myrtles are tough, resistant plants, it is worth taking a little effort to give them a good start in life. Once you have decided where to place your tree, dig over the area you are planning to plant in, going down to the full depth of your spade and turning the soil over while removing weeds and their roots. Don’t worry about taking out stones unless they are bigger than your clenched fist. Add some organic material to the soil to encourage root development. This could be garden compost, well-rotted manure or rotted leaves. If you don’t have these materials, then some peat-moss can be used instead and that is readily available everywhere. Mix a big bucket of this organic material into the soil of the planting area of each tree.
Before planting, give your potted tree a good watering. If you can do this the day before planting that is ideal. When you are ready to plant, remove the pot. If there are a lot of tight roots wrapping around the root-ball, take a sharp knife and cut from top to bottom in three places, going no more than an inch deep. You can do this even if your tree is in full-leaf. Don’t worry, you won’t hurt it. The reason for doing this is to encourage the roots to spread outwards into the surrounding soil, rather than staying in the root-ball, where they can eventually strangle the tree as the spiraling roots grow thicker.
A very important part of planting Crape Myrtles is the planting depth. These plants have shallow roots and should not be planted too deeply. Dig the hole two or three times the width of the pot, but only to the same depth as the pot. Once you have dug your hole, add soil if necessary and press with your foot in the bottom of the hole to make sure the soil is firm underneath the plant. The correct depth will leave the top of the root-ball level with the soil surface, with very little or even no soil at all covering the top of the roots.
Place your plant in the hole you have dug and put back about three-quarters of the soil. Using your foot, firm the soil down around the roots, so that there are no air-pockets in the soil and so that the tree is held firmly. Fill the hole to the top with water and wait for it all to drain away. When all the water has gone, replace the rest of the soil and make everything level and neat. You don’t need to add any more water. You should mulch the roots with a thick layer of organic mulch. This should be 3 to 5 inches thick and completely cover the root zone and a little further out. Keep the mulch off the trunk. The mulch will reduce weeds, conserve water and keep the soil cooler during the hottest weather. All these things will help your Crape Myrtle grow better.
Crape Myrtles grow quickly and soon your plant will be sending roots out into the new soil and starting to grow. You do not need to use a stake on your tree, in fact that is a bad idea, rather like giving a child a walking stick – your plant will be stronger and tougher without being held up artificially.
Although Crape Myrtles are tough, drought-resistant plants, this does not mean you can just put a young plant into a difficult spot and forget about it. During their first growing season Crape Myrtles, like all young plants, should be checked for water and given some fertilizer to get them started on their life. Always remember to water young plants thoroughly once a week during their first growing season. Give them a big, deep drink and then leave them. If you are planting during summer, check your plant each day for water, as it may dry very quickly during hot weather, especially if you are gardening on sandy soil. More plants are killed by little sprinkles of water every day than are killed from never being watered at all. After that first year you should only need to water during extended drought periods. Some liquid fertilizer suitable for trees, mixed according to the directions, can be given once a month during the first year or two to encourage strong, rapid growth.
Growing Crape Myrtles in Containers
The smaller Crape Myrtles are terrific plants for growing in containers. You may have a small garden with no more room, a terrace around your pool you want to make more colorful, or a balcony with no garden at all. Instead of planting and re-planting annuals every year, Crape Myrtles will bring color all summer long and just come back again year after year.
Choose a container that is twice the diameter of the pot your plant was delivered in. Sizes of 16 to 24 inches are about right, with the larger size sufficient for a bigger plant like ‘Catabwa’ or ‘Pink Velour’. It is vital that your container has drainage holes so that the soil doesn’t stay wet. If you can avoid using a saucer under the pot that is also a good thing, since your plant should not be left standing in a saucer of water. If you have to use a saucer be sure to empty it after each watering. Clay pots are better, and more attractive, than plastic for Crape Myrtles, as they allow the soil to breath better, but they are not essential. If you are planting into boxes or built-in planters, they too must have some way for excess water to drain away.
The soil for containers can be regular potting soil. If you can find a type designed for outdoor planters that would be best, but otherwise add some shredded bark, perlite or Styrofoam chips to the soil, about 1 part to 4 or 5 parts of potting soil is ideal. This will improve the drainage and protect your plants from ‘wet feet’.
Water your new plants thoroughly the night before planting and also dampen the soil you are going to use. If you are using a new clay pot, soak it in water for an hour or two before using it. Cover the drainage hole(s) with a piece of stone or some window screening scraps. Don’t put a layer of gravel at the bottom of the pot – it does no good and just reduces the amount of soil available for your plant to grow in. Fill the lower part of the pot with soil so that the plant will sit at the same depth it was in the original pot – no deeper. Remove the old pot, place the plant in its new home and fill around it with potting soil. Firm down gently, don’t press hard, and leave an inch or two at the top of the pot so as to make a space to hold water so that it soaks well into the soil. Water thoroughly until you see excess water leaving the drainage holes.
Always let the soil in your container become moderately dry before watering again, and always water until excess leaves the drainage holes every time you water. Use a liquid fertilizer once a month from the first sign of leaves until late summer. Don’t feed in the fall. If you are getting a lot of foliage and not too many flowers skip a couple of feedings until flowers develop. You may find in the first year you get a lot of growth and only flowers in the fall, but in later years you will have flowers all summer. After a few years it is helpful to top-up the pot with fresh soil each spring, but always leave room for watering.
Place your container in the sunniest, hottest place you can. If you live in zone 6 or the colder parts of zone 7, it is a good idea to bury the pot in the garden for the winter, or wrap it in insulation and move it up against a building wall, as the roots are more sensitive to cold than the top growth. In colder zones move the plant into a cold but frost-free area for the winter. It cannot be kept in a warm place during winter as it needs cold to properly develop its buds for the next year, but it should not be exposed to too much frost either.
Caring for Crape Myrtles
One of the great things about Crape Myrtles is that they don’t need much care. This is one of the toughest flowering shrubs available and they just thrive on sunshine and dry soil. To get the most from them and to have the best display of flowers, some simple care will however go a long way and make your Crape Myrtles the best ones around and the envy of your friends and neighbors.
Each spring you should add a layer of mulch over the roots of your plant. This should be 3 to 5 inches deep and should extend out beyond the line of the foliage, but not touch the trunk of your tree. Use something organic like garden compost or rotted leaves rather than bark or stones, which will not add any nutrients to the soil. Old mulch from previous years can be removed if it is woody and hard, but otherwise it can just be covered with the new mulch.
When your plants are young, some fertilizer is helpful to encourage them to grow vigorously and become well-established. In the first year a liquid fertilizer is best. Choose something with balanced numbers, like 20-20-20.
In later years a granular fertilizer is more suitable and it should be applied in spring, as soon as any sign of growth is seen. This can be sprinkled over the mulch. Numbers like 10-10-10, 8-8-8, 12-4-8 or 16-4-8 all work well. Avoid something with a high first number, like 25-3-3, as this first number is nitrogen and it will cause rapid growth and big, green leaves but fewer flowers. A light sprinkle of fertilizer over the whole root-zone is all that is needed and you should avoid heavy fertilizing. This zone extends about a foot further out from the plant than the spread of the leaves. Keep fertilizer away from the trunk area. If your plants are growing well, and especially if you are getting a lot of leaves and not so much flower, then skip the fertilizer completely. If you want to grow your Crape Myrtle organically, products like soya-bean meal, cotton-seed meal or alfalfa pellets are suitable, although usually rich mulch will be all that is needed.
Pruning Crape Myrtles
If you have chosen your varieties wisely you should only need to do a little pruning. You should never prune your Crape Myrtles in fall or winter as this can make the plant more susceptible to winter injury. In warmer areas where there will be no winter damage you can prune in spring while the plants are still dormant, but in colder regions it is best to wait until the growth is just beginning, so that you can easily see any dead parts and where to prune back to.
Crape Myrtles flower at the end of new shoots produced in spring. So pruning should only be done before the new growth begins. If you cut new growth you will probably get no flowers, or only small ones late in the season that may grow from side shoots.
General pruning consists of removing thin, weak stems so that you have a good framework of strong branches. If you want a more tree-like form, remove the lower side branches as the bush grows upwards, leaving one or a few stems to form trunks on your tree. Remove any new shoots that form on the bare parts of the trunks. Having bare trunks also allows the beautiful bark of many varieties to be seen all year, not just in winter.
To encourage a bushy form, remove the last few inches of the branches so that more side-shoots will form. To develop a taller plant, leave long growths un-pruned and remove side branches.
Traditional gardeners often grow their Crape Myrtles as pollards. This means cutting the branches back to stubs each year, on a single stem or several stems. This was usually done to keep plants smaller but now that we have a wide variety of sizes available it is not so necessary. However it is still an interesting way to grow plants in a more formal way, beside a walkway or in the centre of flower beds. When this is done the plant will send up a number of strong shoots with very large flower heads. The weight of the flowers can cause the stems to bend over, which is attractive if it is not too severe. Stakes can be used to hold up the stems if they bend too much or are in danger of breaking. The very large flower heads are spectacular and this method of growing can be very attractive, but it is more work than the more modern approach of limited pruning.
If you are using Crape Myrtles as a screen, trim the branches back in spring to keep them neat and to encourage a narrower shape. The top can be trimmed level at this time too. Trimming will encourage dense growth and make a more solid screen. Of course if you do not trim the trees will still grow together and make a more informal barrier.
Another interesting and novel way to grow Crape Myrtles is as an espalier. This means to grow them on a wall. Choose a sunny wall, facing south or west and plant your tree right at the bottom of the wall. Select strong branches and tie them to the wall as they grow. It may be easier to stretch wires about a foot apart along the wall and tie the branches to them, especially in a brick or stone wall. Curve the branches over as they grow, which will encourage more side branches to develop and give more flowers. Once the framework is mature, each spring cut the side branches back to an inch or so in length. Flower shoots will develop all over the plant. This method makes it possible to grow a large plant in a limited space, so it is especially useful in small gardens. If the wall is outside a heated building, like a garage or your house, it will also provide warmth in winter and make it possible to grow larger plants in zone 6 and even in zone 5.
If you don’t have a suitable wall, espalier Crape Myrtle can also be grown on a fence or on a specially-built wire frame-work as well. Drive poles into the ground every 8 to 10 feet and stretch fencing wire 18 inches apart, with the top wire at the height you want your screen to be. In this way a narrow ‘hedge’ can be constructed to screen one part of the garden from another with attractive flowering plants at a suitable height for your purpose.
Keeping Your Crape Myrtle Flowering All Summer Long
As new stems grow they will develop flower clusters at the end. These will be the first flowers to open and once they have finished flowering, seed-heads will develop. To make sure that your plants continue to flower, remove these heads as the last flowers are fading. Side shoots will develop with more flower clusters, which will be a little smaller than the first ones. Keep removing the old clusters before they develop much seed and flowers will keep on coming and coming until they are killed by the first frost, or the weather becomes too cold.
Pests and Diseases
Crape Myrtles are tough, hardy plants that do not have serious problems, but there are a few things to watch for.
Powdery Mildew: this disease was a major problem with older varieties, especially when grown in humid regions, like the South. It is much less of a problem in drier areas such as Texas, California and New Mexico. Powdery Mildew is a fungus which grows on the surface of the leaves and forms a white coating, which may be dusty or hard and dry. It doesn’t really harm the plants, but it does make them look unsightly, especially when it grows onto the flower shoots as well. Luckily, thanks to intensive breeding by several important plant breeders, modern varieties are all highly resistant to this disease and you should see it rarely or not at all. This is actually a harmless disease and plants come back the following year perfectly strong and with clean leaves. If you should develop a little powdery mildew, perhaps during a long spell of very hot and humid weather, do not worry, it will not harm your plants.
If you should unfortunately get this disease and want to control it for aesthetic reasons the best method is to use a milk spray. Make a 10% solution (1 part whole milk, fresh or dried, 9 parts water) and spray this onto the foliage. The spray must be re-applied after rain. It has been proven scientifically to work for vegetables so it seems reasonable that it works for ornamental plants too and many people have good results. It will not cure the disease or remove existing white coatings, so begin to spray when you see the very first signs of mildew. This method is much more effective than baking soda, which you will also find recommended – however research has shown it does not in fact work at all.
Leaf Spot Fungus: This disease is usually found only in the Deep South. It causes brown spots to develop on the leaves during warm, wet weather. As these spread the leaves begin to fall, until only the young leaves at the ends of the branches are left. Because so many leaves are lost the plants will lose some vigor and produce fewer, smaller flowers, as well as looking less attractive. If you have this problem frequently, the National Arboretum varieties ‘Tuscarora’ and ‘Catawba’ have some resistance to this disease and so these should be planted to replace the varieties you are growing. To control this disease it is necessary to use chemical sprays containing thiophanate-methyl. Ask at your local garden center. Spray each week once you see the first spots developing. It is only necessary to spray during warm, rainy periods – during dry and cool periods the disease cannot develop.
Crapemyrtle Aphids: these tiny green insects will cluster under the leaves of the plants during spring and summer. You will probably see some with wings and some without. They suck the sap of the plants and may cause yellow spots to develop on the upper side of the leaves. They may not even be noticed until you see a black powder forming on the lower leaves. This is a fungus called Sooty Mold, which grows on the honey-dew excreted by the aphids. This contains sugar from the sap of the plant and the fungus feeds on the sugar. Sooty Mold is completely harmless and does not damage the plant in any way, but it is unsightly. Controlling the aphids will prevent the Sooty Mold from developing.
Natural insect predators such as ladybirds and lacewings will usually keep the aphids from spreading too much. A strong jet of water from a hose squirted into the foliage of your plants will remove many of the aphids too. If this does not work, then spray with insecticidal soap, which can be found at garden centres. Aphids are often a sign you have been watering and feeding your Crape Myrtles too much, so stop feeding them and cut back on watering too. Chemical sprays may work temporarily, but as they kill the predators as well you may end up with more aphids quite soon, unless you keep spraying regularly.
Flea beetles: This small insects, which are metallic green in color, may chew the edges of the leaves but do no serious harm and do not need to be controlled.
Japanese beetles: This is a more serious pest in some areas. The beetle is quite large, with a green head and a light-brown back. It has distinctive white tufts along the sides of its body. It will eat the leaves of many types of plants and makes them look like lace. They tend to cluster together, so you may have a lot in one place. On Crape Myrtles they usually cluster on the ends of the branches as the flowers develop. The best control is to watch for the first beetles to arrive and then shake the branches over a bucket of hot soapy water. They will fall off into the water and be killed. Since the beetles release a chemical scent that attracts other beetles, the sooner you remove them the fewer will come later. Traps are available but these should not be placed in the plants you are trying to protect. Put them instead along the boundaries of your property so that beetles flying in are attracted to them and do not come further in to infest your plants. Chemical sprays can be used, but as these usually kill aphid predators they may actually cause an infestation of aphids to occur.
|Pests and Diseases of Crape Myrtles|
|White powder on leaves||Powdery Mildew fungus||10% milk spray|
|Black powder on leaves||Fungus caused by aphids – control the aphids||Water jet or insecticidal soap|
|Chewed leaf edges||Flea beetles||No treatment needed|
|Leaves like lace||Japanese beetles||Remove by hand or use traps|
|Small green insects under leaves||Aphids||Water jet or insecticidal soap|
|Yellow spots on leaves||Aphids||Water jet or insecticidal soap|
|Brown spots on leaves||Leaf spot fungus||thiophanate-methyl|
|Leaves fall in midsummer||Leaf spot fungus||thiophanate-methyl|