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.