Class preview: spring geophytes

Ornamental onion (Allium)

Planning your spring and summer geophytes

By Kate Blakely
Photo by Robert Ayers

A robin singing, warmth in the wind, a sunshiny breeze, a bright little flash of green and yellow against the brown earth—this mild winter has been laced with signs of spring. So it seems a good time to talk about geophytes.

What’s a geophyte?

“The quick and dirty definition of ‘geophytes’ is plants with underground storage structures,” says Jason Holmes, curator of the Doris Duke Center Gardens, who’ll teach a class on spring geophytes on March 7.

Daffodils, tulips, crocus, gladiolas, dahlias, cannas, crinums and a host of other flowers fit under the term “geophyte.” All of these plants carry their food inside a storage structure such as a bulb or tuber.

Holmes will discuss a variety of spring geophytes in his class at Duke Gardens. But here are two for starters:

Winter aconite (Eranthis hyemalis): This little geophyte rises about 3 inches off the ground. Eranthis is a long way from home; it comes from the high mountains of Turkey. It has a pretty little buttercup-colored yellow flower. “They’re a rare oddity, a unique plant that you don’t find in a lot of gardens around here,” Holmes says. So if you see winter aconite bulbs, make sure to snatch them up and give them a home away from home in your garden.

Ornamental onion (Allium): These eye-catching geophytes also go by the name “drumstick onions.” Despite the food connotations of the name, Holmes does not recommend putting these on salad or in a stew. They’re best enjoyed in the perennial garden, and are among the Duke Gardens flowers that visitors are most curious about. Watch for a tall green spike with a purple ball of flowers on top, appearing from early to mid-May. At Duke Gardens, you’ll see them in the Doris Duke Center Gardens and in the Terrace Gardens.

If you’d like to enjoy spring-blooming geophytes in your garden next year, make sure to plant them in the fall. That’s probably the trickiest thing to remember about spring-blooming geophytes, Holmes says. Folks tend to look in stores for them at the time they see them blooming. “You just don’t find them then,” Holmes says. “You have to buy them in the fall to plant them for spring flowers.” However, you can plant summer-blooming bulbs now through April, such as lilies, gladiolas, cannas, and dahlias.

Bulbs typically need little care. When planting, people may add bone meal as a great source of fertilizer and maybe a little water. Most bulbs detect moisture in the ground and then flush their roots. Tubers should be watered in once planted.

Once the plants detect the right amount of warmth from sunlight and moisture, they begin to grow. Only cut back the foliage once it starts to turn mostly yellow or brown. Mix these geophytes throughout your perennial garden and other sunny shrubs for added flower power!

Want to know more? Consider taking Holmes’ class, “Plants of Distinction: Spring Geophytes,” March 7 from 1-3 p.m. The cost is $25; $20 for Gardens members or Duke staff or students. Holmes’ “Plants of Distinction” series will continue with “Alba: White foliage and flowers” on May 16 and “Hardy Plants with a Tropical Flair” on July 18. To register, or for more information, please call 668-1707 or email our registrar.

Sarah P. Duke Gardens creates and nurtures an environment in the heart of Duke University for learning, inspiration and enjoyment through excellence in horticulture. The Gardens is at 420 Anderson St.

Kate Blakely is a graduate student at Duke Divinity School and a work-study assistant at Duke Gardens. Robert Ayers is a volunteer photographer at Duke Gardens. This column first appeared in the Durham Herald-Sun.

Fall Plant Sale preview

Toad lily is among the plants you can buy
at Duke Gardens' Fall Plant Sale

Gardeners often head to their local public gardens not just to immerse themselves in the beautiful and peaceful surroundings but to draw up blueprints for success in their own yards.
What plants thrive in this region? Which ones make interesting combinations, in terms of color and texture? Which fare better in full sun than one might think, or do surprisingly well in shade?

At Duke Gardens’ biannual fundraising plant sales, they can put those lessons into action, with guidance from the horticulturists and curators who know the plants best.

The Gardens’ Fall Plant Sale, from 9 a.m.-noon Oct. 1 (with an 8 a.m. presale for Gardens members -- info: 668-1711), will feature flowers, vines, trees and shrubs found throughout Duke Gardens, as well as bulbs best planted in fall for spring delights.

We won’t have any outside vendors at this sale, though you can expect them back at our larger sale next spring. Instead, we’re going to free up the lower parking lot for customers’ convenience and hold the sale on the lawn behind the Doris Duke Center. Parking is free.

Jason Holmes, who is curator of the Doris Duke Center Gardens and coordinates the plant sale, offered a few highlights.

Chinese leadwort: This unusual perennial has brilliant cobalt blue flowers and makes a great ground-cover, Holmes says. It likes full sun. Once established, it also tolerates drought well. It blooms in mid-summer through fall.

Chinese leadwort

Toad lily cultivars: This shade-loving, spreading perennial grows to between a foot and 2 feet high. In late summer, it produces brilliant little flowers about the size of a quarter, which are unusual in shape. They’re often white with purple spots. “They’re a nice little novelty plant,” Holmes says.

Propagated plants: Customers are especially fond of the plants propagated directly from Duke Gardens by the volunteer propagation team, so it’s best to arrive early if you’re hoping for these special mementos. The prop team takes requests, too, so speak up if there’s something you’d like to see at next year’s sales.

Gardening books: Thanks to a large and generous donation from a Duke Gardens supporter, our used book sale will be extra big this year. Most books will cost $.50 to $1.

Bulbs: We’ll also have plenty of bulbs, which are best planted in fall but are often a hard sell because they’re not attractive in their bulb state, Holmes says. He encourages people to embrace delayed gratification so they can be rewarded with spring blooms.

“How do they start,” he asks, “if not from a bulb?”

Among the bulbs you can expect to see:

Drumstick allium: These purple balls of flowers towering atop stems like something from a Dr. Seuss book are one of visitors’ favorite plants.

“Those bloom in May around here, but the fall is the absolute best time to plant them,” Holmes says. “Many people are always asking about getting this plant when it’s in bloom, but that’s not the good time to plant it. And it’s usually only available for sale during the fall season.”

Allium. Photo by Alice Le Duc

Colchicum: Known as autumn crocus, colchicums produce a profusion of 2- to 3-inch flowers in pink, white and purple.

“The foliage comes up in the spring, and it typically dies down, and then late summer to early fall is when the flowers come up out of the ground,” Holmes says. “So they’re almost like a surprise.”

Colchicum pannonicum 'Mauve Wonder'

Lycoris: These are also known as the surprise lily, hurricane lily or spider lily, and we expect to have them in red, pink and yellow. You can see some of the red and yellow versions in the Culberson Asiatic Arboretum. The pink – also known as “Naked Lady” – blooms a bit earlier and was featured in the Terraces this year. It grows taller and is more robust than the other colors.

Golden spider lily

“In the spring months you’ll have the foliage come up, and then, much like the autumn crocus, the foliage dies down in early fall,” Holmes says. “In late summer or early fall, you have a giant spike come out of the ground that may contain as many as 20 flowers. It radiates out like a spider. … They’re a real neat oddity in the garden that you don’t really find elsewhere. They’re something for true gardeners to have.”

Hurricane lily

Sarah P. Duke Gardens creates and nurtures an environment in the heart of Duke University for learning, inspiration and enjoyment through excellence in horticulture. The Gardens is at 420 Anderson St. Visit online at gardens.duke.edu. For a brief roundup of events through December at Duke Gardens, please see this blog post. For further information, please go to our education & events page.

This column first appeared in the Durham Herald-Sun. All photos are by Jason Holmes, unless otherwise noted.