Bastard Cress
Thlaspi arvense
Last reviewed: June 2026
Bastard Cress (Thlaspi arvense) is not on the ASPCA Animal Poison Control Center toxic plant list for dogs or cats (aspca.org, last reviewed 2026-05-21). If your pet shows symptoms after eating any plant, call the ASPCA at (888) 426-4435.
Light
full sun
Water
medium
Size
6"–24" H × 3"–12" W
Bloom
May, Jun, Jul
Native to
ND
Pollinators
bees, flies
Browse plants for this ecoregion
Bastard cress is a small annual wildflower that grows up to 2 feet tall with white flowers from May through July. This pioneer species often appears in disturbed soils and agricultural areas. It produces small heart-shaped seed pods that can be somewhat ornamental.
In an HOA neighborhood
Bastard Cress 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 'bastard' which may cause complaints
- Often considered a weed in agricultural settings
- Can self-seed aggressively and spread beyond intended areas
Wildlife value
The small white flowers attract bees and flies during the late spring and early summer months. As an annual, it provides seasonal nectar sources for small pollinators.
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 Bastard Cress fit your yard? Open it in Pollinator Patch to check it against your sun, soil, and HOA-conscious filters.