Coleuses were among the first plants I became familiar with when I started learning about plants as a teenager. I found the incredible variation of colors and patterns in the leaves fascinating. This spring, the LSU AgCenter has named Henna coleus a Louisiana Super Plants selection.
I’m not the only one to find coleuses attractive and interesting. These plants have remained consistently popular for generations – due in no small part to their amazing diversity.
All coleus plants belong to a single species, Solenostemon scutellarioides. Yet, the diversity found within this species is staggering. You see the same thing in dogs. Even though they all belong to the same species, Canis lupus familiaris, the number of breeds and the huge differences in size, shape and color among them are astounding. (It’s hard to imagine a Chihuahua and a Great Dane belong to the same species.)
The stature of coleuses ranges from trailing coleuses with small leaves to types 4 feet or more tall with large, broad leaves. Leaf size can range from 1 inch to several inches. The colors in the leaves may include green, chartreuse, purple, burgundy, red, rose, pink, gold, yellow, orange and white. The leaf edges may be slightly toothed, lobed or frilly. The variations of colorful patterns in the leaves are seemingly endless.
When I first learned about coleuses, they were firmly placed in the lists of shade-loving bedding plants. Coleuses were recommended for use along with impatiens, begonias and caladiums.
The majority of coleuses available at nurseries were seed-grown strains and varieties that tended to bloom readily. I remember the Carefree strain with deeply lobed oak-shaped leaves and Fiji with ruffled leaves. The Wizard series was an improvement over the old Rainbow coleus because it had more compact growth and better branching. Many of these varieties for shade are still available
That all began to change in the 1990s with the introduction of coleuses adapted to growing in full sun. These were often robust-growing plants with large leaves that reached 3 feet tall.
The Solar series is the first group of sun-loving coleus I encountered in LSU AgCenter trials. They included many colors, such as Solar Flare, Solar Sunrise and Solar Furnace. You can still see some Solar coleuses around today.
Interest in using coleus in summer beds has been strong over the past couple of decades, and breeders and plant development companies have released an amazing number of coleus varieties – with more coming out each year. Most new coleus varieties and series are sun-tolerant. Notable exceptions are the Kong and Kong Jr. series, which prefer shady locations.
The LSU AgCenter Hammond Research Station plants a large number of coleus varieties in its trial gardens every year. Plants are evaluated for color, branching, growth habit, sun tolerance and reluctance to bloom.
This reluctance to bloom is important because flowering in coleuses is considered undesirable. The spikes of small, lavender flowers add nothing to the appearance of the plants. Indeed, when coleus plants come into bloom, they tend to look weedy. So coleuses that don’t bloom until fall are considered superior to those that start blooming in late summer.
Henna coleus is one of the varieties that have really been impressive in Hammond Research Station trials over the past few years. Like all coleuses, Henna is not a true annual even though we just grow it for the summer season. It is actually a tender perennial grown as a summer annual. This gives it the stamina to hold up and stay attractive through the long Louisiana summer growing season from April-May to October.
Henna coleus grows to be about 24 to 30 inches tall and 18 to 20 inches wide. The plants branch nicely, which creates an attractive, full, bushy growth habit.
The colorful foliage is shades of gold and chartreuse brushed with burgundy on top and rich burgundy-purple underneath. The leaves are deeply toothed along the edges, giving the foliage a frilly look.
Suitable for growing in full sun to part shade, the foliage color varies with the light – a golden color in the sun and more chartreuse brushed with burgundy in the shade. Coleuses love the intense heat of Louisiana summers.
A notable and very desirable characteristic of Henna is that it comes into bloom very late in the season. When other coleus varieties have sent up flower spikes in late summer, Henna continues to produce leaves and maintains an attractive appearance.
The Louisiana Super Plants program is an educational and marketing campaign of the LSU AgCenter that highlights tough and beautiful plants that perform well in Louisiana landscapes. Louisiana Super Plants are selected a year or two in advance of a public announcement. To see a list of nurseries participating in the Louisiana Super Plants program, go to www.lsuagcenter.com/superplants.
Dan Gill is a horticulturist with the LSU AgCenter. He can be reached at DGill@agcenter.lsu.edu