Calochortus venustus is a California native perennial bulb producing cup-shaped, tulip-like flowers with intricate spots and blotches in combinations of white, yellow, lavender, or deep red on each petal. It grows wild in grasslands, open chaparral, and foothill woodlands up to roughly 11,000 feet elevation. The common name 'mariposa' is Spanish for butterfly, referencing the patterned petal markings.
This species is shaped by California's Mediterranean climate and requires a dry summer dormancy to persist. It needs full sun and sharply drained, sandy or rocky soil; summer moisture is the primary cause of corm loss. Gardeners outside the California native range must replicate dry-summer conditions or grow corms in containers moved to a dry spot from June through September. Planting on a slope or in a raised bed is the most reliable way to ensure summer drainage. Soil pH is flexible as long as drainage is excellent.
Native California tribes including the Miwok and Pomo collected the starchy corms as a significant food source, eaten raw, boiled, or roasted.
Ecoregions:Northwestern Forested MountainsMediterranean California
These dates are for Zone 6b. Enter your ZIP to time every job to your own frost dates.
- sow · Oct 30 - Nov 27Direct sow seed in a gritty pot or bed and leave it outdoors to cold stratify naturally; corms take 3-4 years to flower
- buy · Jul 10 - Jul 24Buy corms - about two months before planting
- buy · Aug 21 - Sep 4Order seed - about two months before sowing
- watch · Any time in summerStop watering once the foliage yellows; summer water rots the dormant corms
- plant · Sep 18 - Oct 16Plant corms 3-4 in deep in gritty, fast-draining soil and leave them unwatered until rain starts
Problems & troubleshooting
Common problems
Root rot
Plants wilt, yellow, and stunt even in moist soil; lower stems and roots turn brown, soft, and mushy and the plant may collapse. Most common in heavy, wet, or poorly drained ground.
Improve drainage and stop overwatering, and never plant too deep. Lift and destroy badly affected plants along with the soil around the roots. Grow in raised or free-draining beds to prevent it returning.
Botrytis (grey mould)
Grey fuzzy mould on petals and stems, worst in cool wet conditions.
Remove affected parts immediately. Improve air circulation. Avoid overhead watering. Apply copper fungicide if severe.