
Calochortus uniflorus
Calochortus uniflorus
Safety & Hazards
None known
Cultivation Details
Calochortus uniflorus is native to semi-arid climates in western N. America, growing in freely draining soils. Whilst being very cold hardy, it can be a rather difficult plant to cultivate in moister temperate climates, being very intolerant of wetness especially when dormant. Requires a deep very well-drained fertile sandy soil in a sunny position and must be kept dry over winter[1, 2]. The plant requires plenty of moisture when in growth, but very dry conditions after it has flowered[3]. The plants should not be crowded by other plants[4]. In moist climates it is usually easier to grow this species in a bulb frame, though it is worth trying outdoors at the base of a south-facing wall, especially with shrubs that like these conditions[5]. Bulbs have succeeded in a cold frame with the cover removed from March to October[4]. Bulbs can be lifted as soon as the foliage dies down in the summer and stored overwinter in a cool dry place, replanting in spring[6]. Another report says that they should be replanted immediately[1]. Bulbs frequently divide after flowering, the bulblets taking 2 years to reach flowering size[2]. The flowers are sweetly scented[3]. When grown in cultivation, hand pollination is usually necessary if seed is required[1].
Propagation
Seed - sow as soon as ripe or early spring in a cold frame in a very sharply draining medium. Stratification may be helpful. Germination usually takes place within 1 - 6 months at 15°c[6]. Leave the seedlings undisturbed for their first two years growth[6], but give them an occasional liquid feed to ensure they do not become nutrient deficient. It is quite difficult to get the seedlings through their first period of dormancy since it is all too easy either to dry them out completely or keep them too moist when they will rot[4]. After their second year of growth, pot up the dormant bulbs in late summer and grow them on for at least another 2 years in the greenhouse before trying them outside. Seedlings take about 5 - 7 years to come into flower[4]. Division of the bulbs as soon as the foliage dies down. One report says that the bulbs must be planted into their permanent positions immediately[1], whilst another says that they can be stored overwinter and replanted in the spring[6]. Stem bulbils, harvested from the stems after flowering[2]. They can be stored cool and dry then planted in pots in the cold frame in the spring. Cite as: Temperate Plants Database, Ken Fern. temperate.theferns.info. 2026-02-20. <temperate.theferns.info/plant/Calochortus+uniflorus>
Pollinators
Insects
References
- [1]RHS Dictionary of Plants plus Supplement. 1956 — F. Chittendon. · Oxford University Press · 1951 · ISBN - ↩︎Comprehensive listing of species and how to grow them. Somewhat outdated, it has been replaced in 1992 by a new dictionary (see [ 200 ]).
- [2]The New RHS Dictionary of Gardening. 1992. — Huxley. A. · MacMillan Press · 1992 · ISBN 0-333-47494-5 ↩︎Excellent and very comprehensive, though it contains a number of silly mistakes. Readable yet also very detailed.
- [3]Scented Flora of the World. — Genders. R. · Robert Hale. London. · 1994 · ISBN 0-7090-5440-8 ↩︎An excellent, comprehensive book on scented plants giving a few other plant uses and brief cultivation details. There are no illustrations.
- [4]The New Plantsman. Volume 1, 1994. — Matthews. V. · Royal Horticultural Society · 1994 · ISBN 1352-4186 ↩︎A quarterly magazine, it has articles on Himalayacalamus hookerianus, hardy Euphorbias and an excellent article on Hippophae spp.
- [5]The Plantsman. Vol. 2. 1980 - 1981. — ? · Royal Horticultural Society · 1980 · ISBN - ↩︎Excerpts from the periodical giving cultivation details and other notes on some of the useful plants including Billardiera spp, Calochortus spp, Drimys spp.
- [6]Growing from Seed. Volume 3. — Bird. R. (Editor) · Thompson and Morgan. · 1989 · ISBN - ↩︎Very readable magazine with lots of information on propagation.
- [7]Flora of N. America — http://flora.huh.harvard.edu/fna/ ↩︎An on-line version of the flora with an excellent description of the plant including a brief mention of plant uses.
- [8]Vascular Plants of the Pacific Northwest. — Hitchcock. C. L. · University of Washington Press · 1955 · ISBN - ↩︎A standard flora for Western N. America with lots of information on habitat etc. Five large volumes, it is not for the casual reader.
- [9]Early Uses of Californian Plants. — Balls. E. K. · University of California Press · 1975 · ISBN 0-520-00072-2 ↩︎A nice readable book.
- [10]Food Plants of the N. American Indians. — Yanovsky. E. · U.S. Depf of Agriculture. · ISBN - ↩︎A comprehensive but very terse guide. Not for the casual reader.