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Rough Milk Thistle

Sonchus asper

Last reviewed: June 2026

Rough Milk Thistle (Sonchus asper)
Photo: (c) Sara Navarro, some rights reserved (CC BY), uploaded by Sara Navarro

Light

part shade

Water

medium

Size

12"–48" H × 6"–24" W

Bloom

Jun, Jul, Aug, Sep

Native to

ND

Pollinators

bees, flies

Browse plants for this ecoregion

Coast RangeSierra NevadaCentral California ValleyCentral California Foothills and Coastal MountainsSouthern California/Northern Baja CoastCentral Basin and RangeMojave Basin and RangeChihuahuan DesertsCentral Oklahoma/Texas PlainsEdwards PlateauSouthern Texas PlainsEast Central Texas PlainsWestern Gulf Coastal PlainSouth Central PlainsSonoran Basin and Range

Rough milk thistle is an annual wildflower with spiny-edged leaves and bright yellow dandelion-like flowers that bloom from summer through early fall. This fast-growing plant can reach up to 4 feet tall and thrives in partial shade with moderate water needs. As an annual, it completes its life cycle in one growing season and may self-seed in favorable conditions.

In an HOA neighborhood

Rough Milk Thistle takes more care to keep looking intentional in a front yard. Maintenance level: low. Consider it for backyard or mid-zone beds rather than the street edge.

Works well in: backyard only.

  • Common name includes 'thistle' which has negative associations
  • Can appear weedy and unkempt
  • May self-seed aggressively

Wildlife value

The yellow flowers attract bees and flies throughout the long blooming period from June through September. Seeds provide food for birds, particularly finches and other seed-eating species.

Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.

Does Rough Milk Thistle fit your yard? Open it in Pollinator Patch to check it against your sun, soil, and HOA-conscious filters.

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