Giant Coreopsis
Leptosyne gigantea
Care
full sun
very low
Fast, Medium; Prefers sand or sandstone.
3–8ft tall , 2–4ft wide
Jan-Dec
Deciduous
Resistant
Prized
Santa Barbara and San Luis Obispo County coastal bluffs and scrub, below 500 ft elevation, endemic to California coast.
Care Guide
Planting
Plant Giant Coreopsis in full sun with fast-draining soil - it prefers sandy or sandstone-based soil and won't tolerate heavy clay or poor drainage. Space it where it has room to develop its characteristic tall trunk (3–8 feet), since it only branches occasionally. Fall or early winter is the best planting window for Bay Area gardens. This coastal California native is cold-hardy to 25°F, so it will thrive in most local microclimates.
After Planting
Water regularly the first year to establish roots, but once established, Giant Coreopsis needs almost no supplemental water - never irrigate during summer once it's settled in. Expect the plant to go summer deciduous, dropping its leaves and leaving a bare trunk; this is normal and not a sign of stress. The main mistake Bay Area gardeners make is overwatering, especially in summer when the plant naturally wants to rest. Prune only as needed to shape the plant; the data doesn't specify timing, so wait until you see how yours grows before cutting.
Endangered & Threatened Species Supported
California endemic; specialist on Opuntia cacti
Wildlife Supported
Birds
Fall and winter seed consumption; important food source during migration and overwintering
Insects
Primary pollinator and nectar forager; critical for colony provisioning
Larval host plant and adult nectar source; supports multiple generations
Primary nectar and pollen forager during blooming season
Multiple species forage on flowers; important pollinators
Early season pollen source for spring-emerging mining bees
Specialist pollen forager during flowering period
Larvae feed on plant tissues; multi-generational use
Spring and early summer pollen collection for larval provisions
+5 more species