Rattlesnake Weed

Hieracium venosum — Aster Family

A native perennial wildflower in the Aster Family that blooms in summer well-suited to shaded woodland gardens.

Perennial North American Native
Hieracium venosum
Hardiness Zone 4+
Light Shade Tolerant
Water Low
Height 2.0 ft
Bloom Summer
Growth Slow

Planting Guide

When to plant

Plant in spring after the last frost date or in early fall, 6 weeks before the first frost. Container plants establish faster than bare root.

Spacing

Space plants 0.8–1.0 feet apart. Closer spacing fills in faster and suppresses weeds; wider spacing gives each plant room to reach full size.

Root system

Roots reach at least 12 inches deep at maturity. Plant the crown at or just below soil level.

Growing Conditions

Sunlight

Part shade to full shade — as little as 2 hours of direct sunlight. This species is well suited to woodland gardens, north-facing slopes, and the shade of mature trees.

Soil & pH

Prefers slightly to moderately acidic soil (pH 4.5–6.5). Most average garden soils fall in this range; a quick soil test confirms your starting point.

Watering

Low water needs. Water weekly for the first growing season to establish roots. After establishment, natural rainfall is usually sufficient except during extreme drought. Once established (typically 1 season), it shows strong drought tolerance and can go extended periods without supplemental water.

Seasonal Care

Spring
  • Cut back dead stems from last year to 2–3 inches above ground as new growth emerges.
  • Top-dress with a thin layer of compost to support the season's growth.
Summer
  • Deadhead spent flowers regularly to extend bloom period and prevent excessive self-seeding.
  • Established plants rarely need supplemental water; deep, infrequent watering beats shallow, frequent watering.
  • No major pruning needed; remove any diseased or damaged foliage promptly.
Fall
  • Leave stems and seed heads standing through fall and winter to support overwintering insects and birds.
  • Divide or transplant in early fall (6 weeks before first frost) for best establishment.
Winter
  • Leave the plant standing — hollow stems shelter native bees and other beneficial insects overwinter.
  • The seed heads attract finches and sparrows through the coldest months.
  • No mulching is needed for established plants; a thin layer of leaves is fine around the crown.

Wildlife & Garden Value

Ecological benefits

  • Member of the Asteraceae (daisy) family — among the most pollinator-rich plant families. The disk florets provide pollen and nectar to hundreds of bee, butterfly, and hover fly species.

Landscaping uses

  • Dry slope or hell strip planting where irrigation is difficult or unavailable.
  • Rock garden or gravel garden specimen; excellent for low-maintenance landscapes.
  • Groundcover or front-of-border plant. Low stature works well along pathways and lawn edges.

Where to Buy Rattlesnake Weed

Buy from specialist native plant nurseries to get the true species rather than a cultivar with reduced wildlife value.

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