Broadleaf Weeds - St Augustine Lawn - Thistle
BES-TEX Weed ID Guide · Broadleaf Weeds
Thistle
Cirsium spp., Carduus spp.
Common Name
Thistle
Latin Name
Cirsium spp., Carduus spp.
Family
Asteraceae
Life Cycle / Type
Annual or perennial (species dependent) · Broadleaf
What Is It?
Thistle is a spiny broadleaf weed with lobed leaves armed with sharp spines and upright flowering stems topped with purple or pink flowers. Some thistles act as annuals, while others are deep-rooted perennials that spread by roots and seed. They commonly occur in thin turf, pastures, fence rows, and disturbed areas. This weed can behave as both an annual and a perennial. Pre-emergent herbicides may reduce new seedlings but will not control existing plants.
Soil Temperature & Germination
Thistle establishment is tied to cool to moderate soil conditions.
Below 55°F
Germination for annual types
Cool to moderate soils
Continued establishment
Decision Question
Is the thistle visible above the soil right now?
Why This Weed Comes Back
Deep taproots or creeping root systems in perennial species
Heavy seed production
Thin or unmanaged turf
Learn the Basics
A healthy, thick lawn is the best defense against weeds.
