PL. —Balsamorhiza sagittataBotanical illustration — drop image
Balsamorhiza sagittata

Arrowleaf Balsamroot

SpringSummer
4a8bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Not in bloom
Summer
Peak bloom
Fall
In bloom
Peak bloom
In bloom
Background

Arrowleaf balsamroot is a long-lived native perennial found on dry open slopes, grasslands, and sagebrush steppe from British Columbia to California and east through the Rocky Mountains. It forms large rosettes of arrow-shaped, silver-gray leaves and produces yellow composite flowers on stems 1–3 feet tall in spring. Established plants are among the most drought-tolerant herbaceous perennials available for western gardens and provide significant early-season pollen and nectar to native bees, including bumble bees and mining bees.

The plant develops a deep taproot that can extend several feet into the soil, enabling extreme drought tolerance but making transplanting nearly impossible after the first growing season. Cold stratification is required for germination; fall direct-seeding into lean, well-drained soil is the most reliable method. First-year plants produce only a basal rosette — flowering begins once the taproot is well established, typically in year two or three. Amended, irrigated, or heavy clay soils cause root rot and shorten plant lifespan. Mulch should not be piled against the crown, and plants in their native range tolerate alkaline soils typical of sagebrush habitat.

Indigenous peoples of the Great Basin and Columbia Plateau used all major parts. Seeds were roasted and ground into meal or eaten whole. Young shoots and peeled roots were cooked as vegetables. Root resin was applied topically to wounds and used in preparations for colds, respiratory complaints, and infection. The genus name Balsamorhiza refers to the balsam-scented resin concentrated in the taproot.

Care guide
SunFull sun
WaterLow
SoilWell-drained, rocky, sandy
Spacing24–36 in
Height12–36 in
Zone4a – 8b
Native RegionAZ, CA, CO, ID, MT, NV, OR, SD, UT, WA, WY
Direct sowFrost hardy
Seasonal tasks
spring
watchWatch for seedling emergence in mid-spring; first-year plants produce only a basal rosette with no flowers.
watchCheck drainage around the crown after snowmelt; standing water or saturated soil triggers crown and root rot rapidly.
watchMonitor for aphid clusters on emerging stems; a strong stream of water is usually sufficient to control them without treatment.
summer
watchWatch for powdery mildew on older leaves during warm, humid stretches; cosmetic on established plants but improve air circulation if severe.
sowCollect ripe seeds before dispersal; store dry in a cool location or direct-sow immediately into a new prepared site.
cutCut spent flower stems to the base after seeds have dispersed; leave basal foliage intact through the season.
fall
sowDirect-sow seeds into well-drained, lean soil in fall; seeds require cold stratification and germinate naturally after winter.
Common problems

Powdery mildew

Symptoms

White or grey powdery coating on leaves — usually starting on older growth in humid conditions or when nights cool.

Treatment

Improve air circulation by thinning plants. Apply neem oil or potassium bicarbonate spray at first sign. Avoid overhead watering.

Phytophthora Root Rot

Symptoms

Wilting despite moist soil, yellowing leaves, stunted growth, and dark, decayed roots and crown tissue. Vines may collapse during hot weather.

Treatment

Plant in well-draining soil and avoid waterlogging. Remove and destroy affected vines. Improve drainage with raised beds or amended soil and avoid overwatering.

Crown Rot

Symptoms

Lower leaves yellow and wilt; the base of the rosette turns brown and soft, sometimes with white fungal threads at the soil line. Plants collapse in wet conditions.

Treatment

Remove and destroy affected plants. Improve drainage and avoid overhead watering. Do not mulch directly against the crown. Space plants for airflow and avoid replanting in the same wet spot.