It’s easy to fall in love with these heat-tolerant, North American treasures
by CARL SCHOENFELD
IT’S NO SECRET THAT I HAVE A PASSION FOR RAIN LILIES, members of the genus Zephyranthes. This isn’t based solely on their jewellike flowers or the tenacious little bulbs that produce them. It also has to do with my encounters, either in print or in person, with some of the collectors who have tramped over unexplored fields before me. The experiences that these extraordinary people shared with me helped to ignite my horticultural interest in one of the New World’s most gardenworthy groups of bulbs.
My involvement with rain lilies began in 1987, when I obtained a photocopied bulb list from an out-of-business nursery called Zephyr Gardens. It sported the enticing title Rare Bulbs from Texas and Mexico—A Unique Collection of New and Rare Species and Hybrids. The nursery, which had its heyday in the late 1960s, had been the brainchild of Thad Howard, a figure well known in bulb circles for identifying countless new species from Texas to Argentina. My interest in native plants had been growing, and the thought of finding dazzling bulbs just a day’s drive south was more than I could stand. Growing up in the Texas hill country north of San Antonio, I was familiar with the giant prairie lily, Z. drummondii, a white-flowered rain lily that comes into flower in early spring and then blooms sporadically after storms until fall, and with Z. chlorsolen, also white-flowered, which probably has the widest range of all the rain lilies. But I was eager to learn more and see rain lilies in other colors, such as the pinks and yellows mentioned in an article entitled “Exploring for Mexican Zephyranthes,” by Katherine Morris Clint of Brownsville, Texas, that appeared in a 1952 copy of Plant Life.
By now I was working at Peckerwood Garden in Hempstead, Texas, and soaking up as much information as possible about plants. I convinced John Fairey, owner of the garden, that we should visit Thad Howard in San Antonio to see if we could obtain any of the bulbs he had listed in his catalog some 20 years earlier. Howard had recently relocated, but was able to share a few bulbs of Z. reginae, then known as ‘Valle’s Yellow’, and two forms of Z. lindleyana. During the visit, I observed a 12-foot-tall columnar cactus with gold spines and a bright green body (Neobuxbaumia polylophus) growing next to the house. Howard said it was a Mexican species, and that there was a lifetime’s worth of plants down there just waiting to be discovered. That was all the fuel we needed to start traveling to Mexico.
By midsummer 1987, having gathered as much information as possible from maps, turn-of-the-century books, and travel logs, John Fairey and I were ready to start retracing the routes of previous collectors. In the 100 or so expeditions that followed, on many of which we were accompanied by botanists and plantsmen from around the world, we discovered and collected seed of new, undescribed species, as well as of many of the plants described by earlier collectors. These collections provided the basis for the rain lilies grown at Yucca Do Nursery, which I began running full time in 1999.
Our rain lily collection at Yucca Do got a big boost in 1996, when I got a call out of the blue from Steve Lowe, owner of Tejas Bulbs, asking if I would be interested in his extensive collection of rain lilies. (He had decided to focus his attention on crinums, and was looking for a home for his collection.) Steve sent a staggering 20 sacks of bulbs, which were potted up individually and then grouped and sorted when they started to flower. Although the process of identification was a long one, eventually we were able to provide all the plants with names. I can’t overstate the value of Steve’s gift, which contained a host of named hybrids, including rarities such as ‘Ajax‘, ‘Aquarius’, ‘Capricorn‘, ‘Grandjax’, ‘Midas‘, ‘Prairie Sunset’, and ‘Ruth Page’, to name just a few. These had long been almost unobtainable commercially—a situation I’ve been working to change.
RAIN LILIES IN THE WILD
It’s believed that the center from which the genus Zephyranthes radiated is the state of San Luis Potosi, in northeastern Mexico. It exhibits incredible climatic diversity—from hot, tropical lowlands and moist, primeval forest that supports remnant populations of Acer, Hamamelis, Fagus, and Liquidambar, to arid deserts dominated by grasslands and cactus. Rain lilies occupy all of these habitats; there are rain lilies, therefore, for almost every climatic zone that doesn’t experience long periods of freezing weather. Gardeners who live in areas too cold to grow rain lilies in the ground (lower than USDA Zone 6 in the continental United States) can imitate the people of central Mexico, who grow their bulbs in pots, protecting them during the cold winter months and taking them out into the garden to enjoy the summer rains. (See “Growing Rain Lilies as Container Plants in Zones 4–7,” page 42.)
That said, Jason A. Delaney, the horticulturist responsible for the bulb and rock garden collections at the Missouri Botanical Garden, has been testing rain lilies to determine whether there are species that can, in fact, be grown outdoors in Zones 5b to 6a. The last couple of winters in St. Louis have been mild, so the jury is still out. Thus far, however, Delaney has had success with Z. candida, Z. drummondii, and Z. flavissima.
In the wild, particularly in Mexico, rain lilies proliferate in disturbed areas and thrive under the nonintensive agriculture practices associated with small-scale farming. There you find them flourishing in sugar cane fields, along irrigation ditches, and in open pastures. In Texas, they proliferate along highways, even when they are being constantly mowed, and in drainage ditches. In both Mexico and the United States, they are passalong plants, and can also be found in vacant lots and abandoned graveyards. This broad adaptability points to a bulb happy under domestication and cultivation. In fact, some rain lilies probably exist only as cultivated plants handed down from pre-Columbian times.
Rain lilies thrive in hot-humid or dry environments that are usually not hospitable to true garden lilies. Rain lilies are smart: they produce their lush foliage in the fall when the weather is cool and moist and thus overwinter disguised as healthy clumps of liriope. In spring, this bouquet of foliage continues to grow and expand, feeding the bulbs that lie just below the surface of the soil. The best time to feed rain lilies is in early fall (in Zones 8b–10) or early spring (Zones 6b–8a). Likewise, the best time to divide or move rain lilies is in the fall in the Lower South or early spring in the Upper South, because that’s when the bulbs are in active growth and you can find them. This allows them to settle in and establish some roots before flowering, and ensures that the weight of the flower won’t cause the bulb to tip over. If necessary, however, rain lilies can be moved even when in flower (which is the only sure way to distinguish them), without any adverse effects on future flowering.
Each species of rain lily has evolved a different time frame or window in which the bulb is poised to flower. Once that window is reached and conditions are right, the plants will bloom. Experience has shown that once within their window, they bloom heavily at two-week intervals, provided that the stimulus of rain or irrigation is provided. These distinct flowering windows mirror the general rain patterns of the areas in which each species evolved. For example, some species bloom in early spring, such as Z. atamasco and Z. lindleyana, which are climatically influenced by winter and early-spring rains, while others wait till mid-May, like Z. primulina, which originated in areas of late-spring rains. Still others wait till summer, for a hurricane or early cold front to bring cooling moisture, like Z. jonesii and Z. traubii.
I know of no other genus of bulbs with such staggered bloom times. You won’t have to wait long to see your rain lilies shine, because with as few as six species you can have rain lilies flowering from the second week of March and continuing off and on until the second week of November. (Peak months are July and August.) That’s nine months of color. Whether you can offer them a pot on a deck in Maine or a flowerbed in Florida, these wonderful, easy-to-grow bulbs deserve a place in every garden. H
For sources of plants featured in this article, turn to page 77.