GV?Gardeners: Summer lilies bloom in desert

With monsoon moisture, rain lilies and spider lilies pop out of the ground, bursting into bloom. These natives of Central & South America and the Sonoran Desert, will send up flowers repeatedly in response to summer rains.

Rain lilies (Zephyranthes) are planted as dormant bulbs in fall or spring. Place in full sun or partial shade, in well-drained soil. They produce bright green, grass-like leaves. Encouraged by a good drenching monsoon rain, singular funnel-shaped blossoms will suddenly appear on slender, hollow stems.

Z. drummondii is now producing large pink flowers. With bright yellow flowers, Z. citrine blooms later in the summer. Additionally, there is a common white flowered evergreen species, Z. candida, also a late bloomer. All of these plants mature at 4 to 6 inches high by 4 to 6 inches wide with flower stems reaching 12 inches tall.

Leaves of rain lilies grow for only a short time after flowering, and will quickly wither. Remove the leaves when they can be pulled easily by hand. Give little or no water after foliage dies back. In summer some leaves will brown on the evergreen species, and they can be removed. Rain lilies spread, and after 4 to 5 years it may be necessary to divide crowded clumps.

Apply slow-release fertilizer in fall and spring. Water established plants weekly in summer, relying on rainfall during winter. They are cold hardy to 23 degrees. Rain lilies are long-lived and are not susceptible to pests or disease. These little plants are quite pretty in a rock garden or border, and do well in containers.

Spider lily (Hymenocallis sonorensis) is a native summer bulb. This large semi-evergreen plant has deep green, 2-feet long, strap-like leaves. But it is the elegant, dangling white flowers that steal the show each summer. This lovely bloom is described by Garden Author Mary Irish as: “extraordinary with a thin saucer uniting the thin, draping petals on tall, sturdy stalks high above the foliage.” These are night-blooming plants pollinated by nocturnal moths, particularly the large hawk moth.

Plant these bulbs in spring or summer in well-drained soil. Spider lilies prefer partial to deep shade or full morning sun. After established, water every 7 to 10 days in summer, every other week in winter. This lily is cold hardy to 25 degrees. Adding mulch around the plant will help retain moisture and protect from winter cold.

The leaves of the spider lily remain on long after blooming. Wait until they are yellow and dry before removing. The bulbs will multiply slowly if not disturbed. An application of slow release fertilizer in spring is recommended. These lilies are not susceptible to pests or disease.

So here we have discovered lilies that are among the most reliable summer bloomers in our desert. They will live many years with little care, returning annually to bloom in response to the welcome monsoon season rains.

Do you want to learn more about plant care and gardening, then share your knowledge with others in our community? The Pima County Extension office at 1100 White House Canyon Road is now taking applications for the upcoming “Become a Master Gardener” program through the University of Arizona. For further information, stop by the office or call 648-0808 Monday through Friday, 8 a.m. until noon.

Mary Kidnocker is a Master Gardener who writes frequently on the subject from a local perspective. Her column appears Sundays. She is president of The Green Valley Gardeners.