Slender Sunflower
Helianthus gracilentus
Care
full sun
low
Fast; Prefers sand but tolerates garden soil.
2–7ft tall , 0–1ft wide
Mar-Nov
Prized
Supports up to 58 butterfly and moth species in Mediterranean California
Interior valleys and foothills of central California from the Diablo Range south to the Tehachapi Mountains, below 3000 ft elevation in grassland and alkali scrub.
Care Guide
Planting
Plant your Slender Sunflower in full sun with fast-draining soil - sand is ideal, but garden soil works too. Space plants to accommodate their mature height of 2 to 7 feet. This perennial has a thick taproot, so choose a location where it can establish deeply and won't need to be moved. The Bay Area's mild winters are well-suited to this plant, which tolerates cold down to 5°F.
After Planting
Water weekly during your plant's first summer to help it establish its deep root system. Once established, cut back dramatically to just once a month during summer at most - this plant evolved in dry chaparral and expects very little water. The biggest mistake Bay Area gardeners make is overwatering; Slender Sunflower's taproot can rot if kept too wet, so err on the side of dry. Expect blooms from spring through November.
Wildlife Supported
Insects
Host plant for larvae; multiple broods per year in suitable California habitats
Early season host plant for larvae; critical for spring brood emergence
Multiple generations utilize plant as larval host; adults emerge spring through fall in California deserts
Leaf beetle species; utilizes plant foliage during growing season
Multiple broods utilize plant as host; common in California grasslands and chaparral
Multiple generations; larvae feed on plant foliage throughout growing season
Polyphagous species; utilized during population irruptions and migration
Southern California populations; late season broods depend on plant availability