GARDENING : Flash! Bulbs Go Off at UCI Arboretum
While the chance to buy them is still months away, next weekend is the best time to see the South African bulb collection at the University of California-Irvine Arboretum.
*
When gardeners from throughout Southern California travel to Irvine in August to buy the bulbs, the plants will be in the dormant stage. Even so, the shoppers line up all the way out to Campus Drive waiting for the gates to open, “and, when they do, it’s a stampede,” says Leslie Knox of Irvine, a volunteer at the arboretum.
Those who like to see the bulbs in bloom can do so next Saturday at the arboretum’s open house. Except for this occasion, the bulb houses aren’t generally open to the public.
Veterans of past sales take the opportunity to browse through the houses, notebooks in hand, filling out shopping lists for August. Others go simply to view the collection.
The arboretum collects and propagates bulb species from the Cape region of South Africa, one of the richest areas in the world for bulb biodiversity, but an area whose bulbs are seriously endangered in the wild due to the pressures of urbanization.
The arboretum, since its inception 18 years ago, has been so successful at cultivating these plants that, for more than a decade, it has had a surplus to share with gardeners.
“These are very choice plants,” says Pat Robinson of Santa Ana, an arboretum volunteer. “You won’t find them in nurseries. You won’t find them in catalogues. You won’t find them anywhere else. And they’re gorgeous.”
Harold Koopowitz, director of the arboretum, would like to see local gardeners growing more of all of these species as an insurance policy toward their survival.
“Some environmentalists would almost rather see a plant go extinct rather than see it only survive in a garden situation,” he says. “But I don’t see it that way. I think the biodiversity we maintain in our gardens is going to become increasingly important.”
Area gardeners are using these species increasingly because they’ve discovered they’re easy.
“They’re adapted to our climate; they’re from an area with soil much like ours, and you don’t have to dig them up or chill them every year like you do with most European bulbs,” says gardener Carol McElwee of Laguna Beach.
Besides, as Koopowitz points out, these plants are tough. Many can take summer water, but they’ll survive without it, which is a good thing to keep it mind.
“Don’t let all this rain fool you,” he warns. “I’ve seen it before. It will be dry again.”
Following is a preview of some of plants in bloom in the bulb houses at the arboretum:
MORAEA
Gardeners who like the dainty, iris-like flowers of the fortnight lily (Dietes) will also like those of its shorter, non-evergreen cousins in the Moraea family. Though they are acclimatized to a wet-winter/dry-summer in the wild, Moraea, unlike some other South African bulb species, tolerate summer water without rotting and naturalize well in local gardens.
McElwee picked up a lavender-blue Moraea at one of the arboretum’s sales after seeing how readily it was reseeding in the ground in one of the bulb houses.
“I want a garden where I edit more than I plant,” she says, “and I look for plants like that.”
McElwee could be busy editing this spring. Though the original Moraea only got as far as the steps leading down to her garden and never actually got planted, its offspring now form a tall grass meadow under the perennials in her garden and are among the first flowers to bloom each spring.
The prolific species McElwee picked up (she’s lost its tag) was probably M. polystachya, according to Koopowitz.
Two other Moraea that aren’t as prolific but are certainly pretty are M. ciliata and M. loubseri. Both are reminiscent of small bearded iris. The former, a low-blooming variety, hides charmingly in its grass foliage; the latter, a dark beauty with deep lavender-blue petals and a black beard, rises well above it. M. loubseri has become extinct in the wild, Koopowitz says, but the arboretum usually does well enough with it to have some for sale each year.
SPILOXENE
If your soil is very moisture-retentive, consider this family of bulbs, which occur naturally in marshy areas, Koopowitz suggests.
Spiloxene canaliculata, a bright yellow, five-petaled star with a maroon-colored eye, is a particularly easy and satisfying species to grow, he says. “If you water them regularly, they’ll bloom up to three months in the spring.”
S. capensis, the peacock flower, is another easy variety. Though white and yellow flowers are more typical, the arboretum also has a rare mauve-pink cultivar with a turquoise-blue throat and black eye.
HOMERIA
The large, cup-shaped flowers of these species are likely to be the first to catch your eye in the bulb houses because of their vivid colors. Picture neon-yellow washed with lime, orange sherbet, salmon-pink, and alternating orange and yellow petals blotched with chocolate brown. The luxurious, strap-like foliage of these species is also handsome.
Many Homeria will tolerate summer water, Koopowitz says. H. flaccida is one of the best for those situations, he says.
Gophers and ground squirrels don’t bother these species either--at least, not more than once--because the bulbs are poisonous. So are those in the Moraea family.
BABIANA
These species are also great candidates for naturalizing, according to local gardeners. Virginia Carlson of Fullerton reports great success with a dark violet species. (Probably B. augustifolia, Koopowitz speculates.)
Though the majority of the tubular flowers in these species are in the lavender-blue range--a color gardeners seem to have an enormous appetite for--this is a large family and these plants also come in white, yellow, pink, cream, and even red-flowered varieties. Some, such as B. odorata, are even scented--a sweetly spicy, clove-like scent in this instance. The arboretum collection contains more than 35 varieties of Babiana.
GLADIOLUS
Glads are one of the arboretum’s great success stories. They were among the first plants it undertook to preserve, and the arboretum now has more than 80 species, including an abundant stock of G. gracilis latifolia, which is now extremely rare in the wild.
If you’re harboring a suspicion they may not have been worth the trouble, you are thinking of another type of Gladiolus.
“These are not the big, stiff, formal monstrosities you get as garden glads,” says Helen Grier of Yorba Linda. “These are delicate, exquisite flowers.”
Garden glads were hybridized from summer-flowering species, which are big, bold plants, Koopowitz explains. The winter-blooming species the arboretum collects, on the other hand, are smaller and daintier. Many, such as G. gracilis latifolia, which has a pale blue flower with a purple stippled throat, look like baby orchids.
Grier has been growing species glads from the arboretum in two gallon containers for more than a decade with great success, but they also do well in garden situations, according to Koopowitz.
G. tristis, which produces large, cream-colored flowers with a greenish cast and faint brown stripes on the upper petals, tolerates summer water particularly well, according to Brad Carter, arboretum curator. Rancho Los Alamitos in Long Beach, where Carter used to work, has had them growing in a plot that’s been watered twice a week during the summer for more than 40 years, he says.
Another advantage of this species, Carter says, is that it’s strongly fragrant after dark.
ROMULEA
Want a meadow under your California natives? There are some good candidates in this family of plants, Carter suggests. Romulea, as do many natives, need to dry out over the summer, but in that situation many naturalize very well.
If the pathways of the arboretum’s bulb houses are any indication, R. tabularis, a lavender-blue star with a bright gold throat, which looks like a bolder version of the native blue-eyed grass, is a particularly productive species.
Most Romulea have small star or cup-shaped flowers, and they produce them abundantly. A few are bolder. The foliage in all cases is crisp and chive-like.
LACHENALIA
These bulb species need very sharply draining soil and no summer water, which is why most gardeners prefer to grow them in pots, but they will naturalize under the right conditions.
Lachenalia produce many small, urn-shaped, rather fleshy flowers on tight spikes, which Carlson describes as “looking like exotic grape hyacinths.”
In terms of color, many are on the subtle side--pale blue or lime or buff--but a few are quite bold. One, the staff-favorite L. viridiflora, a milky turquoise color, is already out of bloom, but L. mutabilis, which starts out mustard at the base of the spike, turns lavender mid-way up and bursts into electric blue at the top, should still be going strong.
The UCI Arboretum Open House takes place 10 a.m. to 2 p.m., March 6. The arboretum is on Campus Drive in Irvine, near the intersection at Jamboree. Admission is free to Friends of the Arboretum, $5 for the general public. The open house will include guided tours, a plant sale (orchids, South African plants, and a selection of miniature roses) and light refreshments (wine, cheese and assorted snacks). For additional information, call (714) 856-5833.
