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Limelight Hydrangea

Written by Dave Gs • August 15 Modern Twists on the PG Hydrangea

If you live in colder parts of the country, the chances are good that you have seen the PG Hydrangea, even if you didn’t know what it was. This plant is a true garden classic anywhere winter temperatures fall below minus 10, the limits of zone 6. In these colder areas the ‘ordinary’ hydrangea (Hydrangea macrophylla) doesn’t flower, because it needs some branches from the previous year to develop flower buds. Old wood is killed to the ground in colder weather, so they will grow back, but rarely flower. Today there are some excellent new varieties, like the Endless Summer Hydrangea, that will bloom well even when grown in zone 4 and 5. There, with temperatures in winter falling to minus 30, you can still have beautiful pink blooms. However, if you want larger shrubs for height, and easy care, then the PG Hydrangea is still your best choice in cold areas, and a great shrub to grow even in warmer regions.

This plant, known as Hydrangea paniculata, flowers in big conical clusters at the ends of new branches produced from hardy stems that overwinter easily, even when the mercury falls to minus 40. It is a large shrub, coming originally from China and Japan. An American called George Hall, a pioneer trader in Yokohama with a company called Walsh & Co. introduced it to America. In the 1860’s he sent over several new Japanese plants, including a garden form of this hydrangea, called ‘Grandiflora’ because of its large flower clusters. It soon became known as the ‘pee gee’ hydrangea, as the full name was rather long! This is also often written as PG Hydrangea – take your pick.

When it was discovered how hardy, and how easy to grow this plant was, it was soon in every garden. No wonder! With its huge conical flower clusters atop every stem, this plant really stands out in any garden. The flowers begin green, and as the clusters expand and grow they turn white. From midsummer into early fall, this lovely shrub brings interest at a time when few shrubs are flowering. Then in fall, as the cooler weather arrives, the flowers turn first rosy pink, and then rich red, creating a spectacular display.

For gardeners, this hydrangea has many advantages over ordinary hydrangea plants. It is more drought-resistant, an important feature in these times of water conservation. It will grow well in both sun and shade, so it can be placed almost anywhere in the garden. It does not mind if your soil is acid or alkaline, and its white flowers will be pure white in any soil. All it asks for is a well-drained soil, and perhaps some mulch over the roots in spring.

Since that first introduction, there have been many new forms of this beautiful plant created. Variations in size and flower color, as well as richer fall colors, have all been developed. The new PG Hydrangeas are definitely worth choosing over the standard form, so let’s take a look at some of them.

Tardiva White Hydrangea

This is a greatly improved form of the original pee gee, and it is identical to the variety ‘Floribunda’. It has longer, narrower flower clusters than the pee gee, so they are don’t bend over, and flop, a big fault with the original pee gee hydrangea. They remain beautifully upright and arching, making a great backdrop to other shorter plants. In fall, the flower clusters turn from white to shades of pink, taking on the tones of the season. Remember to cut some while the color is still strong. Strip the leaves away and hang them upside down until they dry. Placed in an empty vase they will bring color into your home all through the winter months.

Little Lime and Limelight Hydrangeas

These beautiful newer PG Hydrangeas have very modern looking lime-green flowers, rather than the traditional white ones. This stunning effect brings a very different look, and it is loved both by gardeners and flower arrangers. The main difference between these two varieties is size. The Limelight Hydrangea grows to between 6 and 8 feet tall, depending on how hard you prune it. The beautiful Little Lime Hydrangea only grows between 3 and 5 feet tall, making it perfect for a smaller garden. Since it grows smaller, less pruning is required, unless you want a very compact plant.

Both of these lovely varieties turn rose-pink in fall, and because they are small they make perfect plants for containers – so you can decorate your sunny or shady patio with beautiful flowering shrubs in large pots – a wonderful decorating look.

Colorful New PG Hydrangeas

If you want more color, then consider growing the bright pink Sunday Fraise Hydrangea, or for a powerful end to the season, plant the Fire and Ice Hydrangea, with its amazing flowers that start white, turn pink in summer, and then deep crimson in fall – a stunning kaleidoscope of color changes.

Pruning PG Hydrangea

Left to grow naturally, most PG Hydrangea bushes will reach perhaps 12 feet tall and 10 feet across – a size suitable for a large property. In most gardens, especially if you have not chosen a smaller variety, you will want to prune it, and keep it more manageable.

There are three levels of pruning suitable for these plants, and all are done in late winter or very early spring, before any new growth is seen. The lightest pruning is simply to remove small, weak and crowded branches, and cut off the old flowers, back to the first buds you can see. If any branches have died, you will be able to tell them – and remove them – because the bark will be wrinkled and darker in color. Live branches have a thin green layer beneath the bark.

Harder pruning begins the same way, by removing weaker branches, but then the flowering stems are cut back to leave 4 buds on the stem. The third method is very similar, but this time you cut back to just two buds.

Each method gives different results. The fewer buds you leave, the later the flowers will form in the season, but the larger the flower clusters will be. The choice is yours, and if you have several bushes you can even prune them in different ways, depending on how soon you want to see flowers.

As well, you can prune for the shape of your bush. You can have one or just a few main stems, like a small tree, by removing most of the lower branches completely, or leave several strong stems low down, to produce a bush that is leafy right to the ground. Trained in different ways, these great shrubs bring so much to any garden, they should be planted everywhere.