Extension > Garden > Diagnose a problem > Is this plant a weed? > Broadleaf Weeds > Basal > Bull Thistle
Bull Thistle
Cirsium vulgare (Savi) Tenore
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Found in:
- Prairie and landscape plantings, and lawns (occasionally)
Characteristics:
- Biennial plant that produces a basal rosette and long taproot the first year
- Upright flowering stem grows 2-4’ tall the second year
- Stem is large, heavily branched and covered with dense hairs
- Leaves are coarsely lobed with a long, sharp spine on each tip
- Upper leaf surface is covered with stiff hairs and spines; lower surface is covered with dense, woolly, gray hair
- Compact reddish purple flower heads, 1-2” in diameter, bloom June through Aug
- Root system has a long taproot and underground stems (rhizomes)
Significance:
- Minnesota Primary Noxious Weed that spreads rapidly and aggressively from the extensive root and rhizome system and by seed
