Garden Edition: Coleus Gets a Wake-up Call
by Linda Coyner
About 10 years ago, coleus began to awaken from a long slumber. Since then, amazing new hybrids have stirred a passion that rivals that of the Victorian era. While it’s not likely you’ll see coleus used over great expanses of lawn in precise, geometric designs or forming concentric circles of around the base of a pedestal bejeweled with a gazing globe, it’s certain you’ll be seeing a lot more of it. Coleus is already keeping the same company as it did back in the 1800s, sharing beds with such tropicals as canna and elephant ear.
The ornamental plant that Dutch traders introduced to Europe in the mid-1800s is thought to be related to S. blumeri, which has nettle-like leaves variegated yellow to dull red to purplish. The psychedelic leaf patterns and colors are the result of natural genetic variation.
It’s no wonder that coleus comes from an interesting family, the Labiatae or mint family. Herbs and shrubs in this family are rich in volatile oils and are recognizable by a four-angled or square stem. The genus Coleus, recently renamed Solenostemon, encompasses 60 or so species, some of which are aromatic or medicinal, such as S. forskohlii, which is used in Eastern medicine for asthma and glaucoma.
One aromatic coleus, S. canina-hybrid is currently marketed to repel dogs and cats (see www.millstadtjungplants.com). Glasshouse Works, a coleus specialist, describes the smell of the crushed leaves as “’Eau de Firehydrant’ fragrance.”
Plants from the Victorian Era thrived in the sun as well as shade as their wide landscape use indicates. So how did coleus go from sunny lawns to shady nooks and brilliant to boring?
Coleus’ fall from favor is blamed on an industry cost-cutting measure. The early practice of growing plants from cuttings meant that growers had to winter over cuttings in heated greenhouses. Seed-grown types, on the other hand, flower and go to seed readily in the fall, making seed collection easy and allowing growers to start new plants every spring.
But what made seed collection easy for growers translated into an inferior plant that made work for the gardener. By season’s end, plants went to flower and had to be endlessly deadheaded, and then declined. In addition, seed-grown plants were less tolerant of the sun and most at home in dappled shade. Grown in full sun, their vivid colors turned ghostly.
The wake-up call came in the early 1990s. Growers and specialists began uncovering the old varieties and importing new and different types. While some of the introductions were seed-grown, most became vegetatively propagated from cuttings.
The newly created hybrids are more akin to a perennial than an annual. Their vigor and easy-rooting make it easy for the gardener to make cuttings and keep them year after year. Many thrive in full sun and flowering has been significantly reduced.
Many of these new cultivars were bred for sun tolerance, and most deliver on the promise. Exhaustive trails in the sun-baked fields of Florida, Georgia, and Texas have demonstrated which cultivars can thrive in frying-pan conditions. See more about those trails further on.
Colors and color combinations cover the spectrum, from subtle to screaming. The palette ranges from deep burgundies and lime greens to straw yellows and sassy reds in all shades and blends. Margins and veins often add a contrasting accent.
Leaf patterns are equally diverse, suggesting such things as paisley, fine lace, tattoos, abstract art, 1950’s polka dots, or even oriental rugs. No description can do them justice.
Take a look at two on-line photo galleries: http://www.glasshouseworks.com/trop-c2.html and http://www.glasshouseworks.com/trop-c3.htmll. The new coleus hybrids come with an added bonus: whimsical names. Some of my favorites include ‘Flirtin’ Skirts,’ ‘Inky Fingers,’ Pistachio Nightmare,’ ‘Religious Radish,’ ‘Killer Klown,’ ‘Purple Ducksfoot,’ ‘Appaloosa,’ ‘Fright Night,’ and ‘Large Marge.’
There are other changes, too. The hybrids offered a a wider variety of habit, leaf form, and size than yesterday’s coleus. You’ll find sturdy upright growers reaching 5 feet like ‘Atlas’ and ‘Florida Sunrise.’ A few are low growers, such as ‘Trailing Red’ and ‘Trailing Green.’ ‘Thumbellina’ mounds at less than a foot, and ‘Ducksfoot’ reaches about 18 inches. However, most cultivars stop growing at about 2 feet. Leaves, though usually spade shaped, come in all sizes. They can be narrow like ’The Line’ or broad like ‘Atlas,’ ‘Florida Sunshine Jade,’ ‘Japanese Giant, ‘or ‘Solar Sunrise.’ The name “Ducksfoot” describes the tiny, lobed leaves on several cultivars. Some leaf margins are scalloped like ‘Atlas’ or frilly like ‘Red Ruffles.’
I came across a few varieties that break with the tradition of the unsightly flower spike. Glasshouse Works reports that ‘Japanese Giant’ sports a lovely violet-blue flower. ‘Trailing Red’ and ‘Trailing Green,’ which are ideal for hanging pots, bear blue orchid-like flowers continuously without elongating, according to Log House Plants (www.loghouseplants.com).