Yellow Indian Paintbrush SEEDS (Castilleja sulphurea ) Perennial FLOWERS

Castilleja sulphurea — Yellow Indian Paintbrush, Painted Cups, or Yellow Paintbrush — is a striking native perennial wildflower with pale yellow bracts blooming in summer. Growing 1–2 feet tall, it thrives in moist sub-alpine meadows and exposed flats throughout the intermountain region. A semi-parasitic plant that requires a host plant to thrive; very drought tolerant once established. Full sun to part shade. Excellent for rock gardens and high-elevation native plantings. Blooms June through August.

Plant Highlights

• Pale yellow bracts; blooms June–August
• Native to the intermountain region — moist sub-alpine meadows and exposed flats
• Semi-parasitic: requires a host plant (best grown with grass) to thrive
• Excellent for higher elevations; very drought tolerant once established
• Full sun preferred; tolerates part shade
• Perfect for rock gardens and native wildflower plantings

Sowing Guide

Best sowing time: Winter or early spring — these seeds benefit from cold stratification to break dormancy.

Method: Sow with a thin layer of sand or fine grit as cover. Keep moist in a cool outdoor location.

Cold treatment: If seeds do not sprout within 4–12 weeks, place the damp seed tray in the refrigerator for approximately 4 weeks to provide a cold period. Seeds may take several months to appear — keep the pot or tray in a safe location and be patient.

Host plant tip: As a semi-parasite, Castilleja performs best when grass seeds are sown alongside it in the seed tray or planting bed.

Planting Specs

• Common name: Yellow Indian Paintbrush, Painted Cups, Yellow Paintbrush
• Botanical name: Castilleja sulphurea
• Type: Native perennial wildflower; semi-parasitic
• Bloom color: Pale yellow bracts
• Bloom time: June–August
• Height: 1–2 feet
• Light: Full sun to part shade
• Soil: Medium texture; moist; well-drained
• Drought tolerance: Yes (once established)
• Use: Rock gardens, native wildflower plantings, high-elevation landscapes
• Sowing: Winter or early spring; cold stratification recommended