Baker's Mariposa Lily

Water regularly during the active spring growth period, keeping the soil evenly moist but not waterlogged to prevent bulb rot. Once foliage begins to yellow after flowering, gradually reduce watering, and keep the soil completely dry during the dormant season from late summer through winter.

Grows best in full sun to partial shade, requiring at least six hours of direct sunlight daily to produce abundant blooms. In hotter parts of its range, light afternoon shade helps prevent foliage scorch and extends the flowering period.

Thrives in well-drained, gravelly or sandy loam soil with a neutral to slightly acidic pH, mimicking its native rocky montane habitats. Heavy, compacted clay soils that hold excess moisture will cause bulb rot, so amend with coarse sand or grit if drainage is poor.

Apply a low-nitrogen, balanced bulb fertilizer in early spring just as new growth emerges, to support flower development and bulb health. Avoid high-nitrogen fertilizers, which encourage excessive foliage growth at the expense of blooms, and do not fertilize during the dormant period.

Prefers cool to moderate spring temperatures between 50-75°F (10-24°C) during active growth, and is cold hardy to USDA zones 5 through 8, tolerating winter lows down to -20°F (-29°C) when bulbs are planted at the correct depth. Winter chilling of 8-12 weeks below 45°F (7°C) is required for proper spring sprouting and flowering.

Remove spent flower stalks after blooming if seed collection is not desired, to redirect energy back to the bulb for the next year’s growth. Allow foliage to yellow and die back completely before trimming it away, as the leaves photosynthesize to store nutrients in the bulb during this period.

Most commonly propagated from seed, which requires 2-3 months of cold stratification before sowing, and takes 3-4 years to produce flowering-sized bulbs. Mature clumps can also be divided in late summer during dormancy, carefully separating offset bulbs from the parent bulb and replanting immediately at the same depth.

Tolerates low to moderate humidity levels between 30-60%, typical of its native montane environments. High humidity during the dormant season increases the risk of bulb rot, so ensure good air circulation around planting sites in wetter climates.

Container-grown specimens should be repotted every 2-3 years during dormancy in late summer, carefully removing the bulbs from the old soil, discarding any rotted or damaged bulbs, and replanting in fresh, well-drained potting mix amended with grit. Plant bulbs 2-3 inches deep, spacing them 3-4 inches apart to allow for growth and offset development.