Owl’s Clover Seed (Castilleja exserta)

A fast growing, super showy spring annual, that grows to about 12-inches in height, owl’s clover isn’t a clover at all but rather is a paintbrush (Castilleja species). Like others in its genus, this is a semi-parasitic plant – generating some of its own energy through photosynthesis, but also attaching itself to other plant species via root-like haustoria to “borrow” nutrients from its neighbors.

With a natural range from about the California-Oregon border, owl’s clover naturally extends south and eastward into Arizona, New Mexico, and Mexico. That said, this shockingly pretty little plant is somewhat adaptable a bit further north as a showy garden annual in moderate maritime climates. (One might try it as a show-piece ornamental in gardens as far north as Vancouver Island, but it won’t persist naturally from year-to-year in northern climates without annual replanting). 

The leaves and bright purple flower-like bracts are caterpillar food for several species of checkerspot butterflies including the striking Edith’s checkerspot (Euphydryas editha) which has various imperiled sub-species.

This is a sun-loving little plant that likes warm spots. Across California it sometimes emerges in and around vernal pool environments as they dry out in late spring and early summer, so planting spots with a bit of heat and some residual winter moisture are likely optimal places to try growing it. As owl’s clover “enjoys” the company of a host plant to borrow nutrients from, we recommend inter-planting it with various native grasses and wildflowers – some likely candidates are various fescues and Asteraceae (possibly yarrow, Oregon sunshine, and others).

Note that the small seed is a challenge to handle and is best sown carefully into raked bare ground between other vegetation.  

Approximately 100+ very, very tiny seeds (0.1 gram)