Written by davethetreecenters • February 20 Diervilla, a Neglected Native Shrub – neglected no more
With so many plants in the world, it is inevitable that some good garden plants get overlooked. This is especially a problem in America, because our gardening is built on a foundation of migrants coming from England and Europe, bringing with them their Old-World favorites. Indeed, with the insatiable appetite in Europe for novelty, there are plenty of American plants that are more widely-grown over there than they are back home.
Among these neglected plants is one that probably also suffered from being christened ‘bush honeysuckle’, since the true honeysuckles that grow as bushes have gained a poor reputation for being a) boring and b) invasive – a combination that is fatal for any plant. Those plants are called Lonicera, but the plant I have in mind is called Diervilla. Although pretty closely related, this plant isn’t honeysuckle, and has many virtues that make it valuable in your garden. (Not that all honeysuckle are bad or boring – the twining honeysuckles, with their fragrant flowers, are terrific garden plants.) It is also related to the much-more-popular Weigela, a colorful Japanese shrub that is widely grown.
Diervilla are small deciduous shrubs that grow at ground level in open woodlands or on rocky slopes, forming thickets and clumps. They have simple oval leaves and flower on new stems, with a cluster of pale yellow flowers forming at the end of the new growth, continuing from late spring through most of the summer. These are small but charming, and attractive to butterflies and moths. Although pronounced ‘Deer-villa’, they are probably deer resistant, although there are some contradictory reports out there.
These plants are interesting for gardens not so much in their natural forms, but because in recent years they have attracted a lot of attention from breeders, and new varieties are coming out that promise to become significant and valuable shrubs. Their virtues are many, and collectively we are looking at new plants that are:
- Drought tolerant but will also grow in wet soil
- Able to grow from full sun to full shade, but best with some direct sun
- Blooming continuously through summer
- Attractive to butterflies
- Excellent for fall color – this is the most significant development, and the best of these plants can rival the familiar burning bush for beauty, but without that plant’s invasive habits
That’s quite a list when it comes to selecting plants for landscaping, where you want interest but need things that are virtually self-sustaining and low maintenance. Diervilla delivers.
A More Detailed Look. . .
To get technical for a moment, there are currently just three species, closely related to each other and capable of crossing together – a useful thing when it comes to creating new varieties for gardens. Let’s look at them.
Diervilla lonicera – northern Diervilla (I am avoiding the more usual ‘bush honeysuckle’ name). this species is found over a large range, from Quebec to Georgia and west to Indiana and Kentucky. It can be recognized by its hairless shoots, distinct leaf stalks, and for its stems being almost square in cross-section.
This species was the first introduced into Europe in 1700, by the French surgeon and botanist Sieur de Diereville – the plants were named after him. It is a small shrub growing to around 3 feet, making a bushy mound and flowering all summer.
Diervilla rivularis – mountain Diervilla, or hairy Diervilla. The rarest of these plants, this species is only found in the southern Appalachians, in Georgia and Tennessee and Alabama – it has become extinct in North Carolina. It is a taller plant, reaching perhaps 6 feet, and recognizable by the distinctly hairy young shoots and leaves which are hairy on the lower side. It is rare in gardens, and wasn’t seen in England until 1903.
Diervilla sessilifolia – southern Diervilla.
This species is also found in the Appalachians, and further south in the Great Smoky Mountains, in Tennessee and North Carolina. As the name suggests, you can tell it by the lack of leaf stalks, with the leaves sitting more-or-less directly on the stems. We don’t know when it was introduced into Europe, but it had to be around the middle of the 19th century, because it soon produced a hybrid with Diervilla lonicera, called Diervilla x splendens. This hybrid was first created in France around 1850.
As you can see, the differences between these plants are minor, and it is reasonably to assume that garden plants could well be hybrids.
Let’s Take a Look at the New Diervilla Varieties
The Kodiak® Series is the group of Diervilla that has had the biggest impact, and turned the most heads. Helped by its release through the well-known proven Winners® label, these were developed by Michael Uchneat, who moved on from teaching at North Carolina State University to running GardenGenetics in Bellefonte, Pennsylvania. He is a prominent breeder of many shrubs, and collected a large group of different Diervilla species and varieties, growing them all together. Among many seedlings of these plants, which pollinated freely among themselves, he selected three, all with different kinds of colored foliage. It isn’t clear how these should be considered, but since they are almost certainly hybrids, they are probably best named as Diervilla x splendens – the name Michael Uchneat prefers – although others often list them as varieties of D. rivularis.
Kodiak® Orange has young leaves of reddish orange which turn green in summer and then outstanding fall orange-reds.
Kodiak® Red has red young leaves in spring, and new growth of red all summer. Leaves turn green shading to red edges as they mature.
Kodiak® Black has solid, glossy purple to burgundy-black leaves in spring and summer.
A Look at Some other Varieties of Diervilla
One of the most unusual is ‘Cool Splash’, a variety of southern Diervilla that has variegated leaves, with a white margin around them. It could be used as an interesting, flowering alternative to the over-used variegated dogwood.
Diva™ (‘El Madrigal’), is a variety of D. x splendens with persistent dark red leaves, that turn bright red in fall. The dark color really makes the pale-yellow flowers ‘pop’.
‘Copper’ is a variety of the northern Diervilla, with bronze to coppery new leaves and orange-yellow fall colors.
Honeybee™ (‘Diwibru01’) is great in shade, where it’s pale yellow leaves are protected from sun-scorch, and really brighten a shady corner. It’s a variety of the mountain Diervilla.
Summer Stars™ (‘Morton’) is another mountain Diervilla that looks ‘normal’, but was selected by the Morton Arboretum for its hardiness and reliability in the upper Midwest and Chicago region.
‘Troja Black’ has solid dark purple-bronze new leaves and turns a rich dark green in summer. Also a mountain Diervilla, it has brilliant fall reds and oranges.
These plants are incredibly easy to grow, but of course like all plants they take a few seasons to really get into their stride. Varieties with colored leaves (except for Honeybee™) should be planted with at least some sun, or they will not color so well, and this is especially true of you care about vibrant fall colors. It will grow in both acidic and alkaline soils; with salt spray; in heavy clay to dry sand; in wet soil or in dry (once established). It’s hardy in zone 4, maybe with a few burned branch tips, but those don’t matter because it flowers on new growth. You can simply ‘plant and forget’, but for the best results, and a more ‘garden-worthy’ shape, pruning in early spring is recommended. Remove any weak, damaged or crowded branches. Cut back the rest by about one-third, leaving a neat, mounding shape. New growth with sprout up densely, flowering on every tip, and your plant will look great from spring through fall. Don’t trim new shoots or you will reduce flowering.
Easy Plants to Enjoy
So, maybe it’s time to seek out some Diervilla varieties, and discover a great ‘new’ shrub that has everyone in the gardening world talking. Happy gardening!