Splitleaf Indian Paintbrush SEEDS (CASTILLEJA rhexifolia ) Perennial

Castilleja rhexifolia — Splitleaf Indian Paintbrush, also known as Rosy Paintbrush or Alpine Paintbrush — is a stunning native perennial wildflower with deep pink to violet-purple or orange floral bracts that light up mid-montane to alpine zones from June through August. Found naturally in woods, along streams, in meadows, and on open rocky slopes. Like all Indian paintbrush wildflowers, this semi-parasitic species requires a host plant to thrive. Very drought tolerant at higher elevations. Full sun to part shade. Excellent for rock gardens and native alpine plantings.

Plant Highlights

• Deep pink to violet-purple or orange floral bracts; blooms June–August
• Native to mid-montane and alpine zones — thrives in woods, meadows, and rocky slopes
• Semi-parasitic: requires a host plant (best grown alongside grasses) to establish
• Excellent for higher elevations; very drought tolerant once established
• Full sun to part shade; rock garden and native wildflower specialist
• Also known as Rosy Paintbrush and Alpine Paintbrush

Sowing Guide

Best sowing time: Winter or early spring — seeds benefit from cold stratification (wet, cool conditions) to break dormancy.

Method: Sow very thinly; cover with a fine layer of sand or grit approximately equal to the seed size depth. Keep moist in a cool location.

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

Host plant tip: As a semi-parasite, best results come from sowing grass seeds alongside Castilleja in the same tray or planting bed.

Planting Specs

• Common name: Splitleaf Indian Paintbrush, Rosy Paintbrush, Alpine Paintbrush
• Botanical name: Castilleja rhexifolia
• Type: Native perennial wildflower; semi-parasitic
• Bloom color: Deep pink to violet-purple or orange bracts
• Bloom time: June–August
• Habitat: Mid-montane to alpine; woods, streams, meadows, rocky slopes
• Light: Full sun to part shade
• Drought tolerance: Yes (once established at elevation)
• Use: Rock gardens, alpine and native wildflower plantings, high-elevation landscapes
• Sowing: Winter or early spring; cold stratification recommended