Bull Thistle is a biennial plant in the Asteraceae (daisy) family that is native to Europe to Siberia, and the Arabian Peninsula. Its name comes from the Greek kersion which means thistle. The plant is spiny all over with a tall branching stem that contains large reddish purple flower heads. The plant often grows 2 to 5 feet tall with clasping leaves that are 8 to 24 inches long. It is often found along the edges of salt marshes, meadows, fields, shores, savannahs, roadsides, and it can invade almost any type of disturbed area where it forms dense thickets that crowd out native plants. Populations of bull thistle tend to be short lived, establishing after disturbance, dominating for a few years, and then declining as other vegetation recovers. Bull thistle prefers sunny, open areas. It grows in all types of soils from moist to dry conditions but prefers moist soil. It is self-pollinated via seed but expect it to take two years until it flowers forming a rosette of leaves the first year and sending up a flowering stem the second year with a solitary flower or a cluster of flowers. This thistle is much easier to control than other thistles. It is a high-value nectar plant for bees and butterflies and the songbirds eat the seeds and use the tufts of the seeds for their nests. The seeds are rich in oil, an important food source for seed-eating birds. Flowers are also attractive to hummingbirds. Members of this genus support the following specialized bees: Thistle Long-horned bee Melissodes desponsus , plus Osmia (Helicosmia) chalybea and Osmia (Helicosmia) texana. Thistles are a great option in your meadow garden or naturalized area when looking for a plant to attract pollinators and seed-eating birds. However, this species is considered a noxious weed in many areas of the United States. Please consider planting the Native Alternative Plants shown in the left sidebar. Insects, Diseases, and Other Plant Problems: No significant problems.
Curated pairwise relationships between this plant and others in the library — who feeds
whom, who competes, who confuses the pests. Green reads as a good pairing, red as one to avoid.
No curated interactions recorded for this species yet.
Also noted by NC State
Related species the NC State Plant Toolbox flags for this plant — look-alikes to tell
apart, and plants that play a similar role in a planting. Ones we carry in the library are linked.
Full sun (6 or more hours of direct sunlight a day)
Soil texture
Clay; Loam (Silt); Sand
Soil pH
Acid (<6.0); Alkaline (>8.0); Neutral (6.0-8.0)
Soil drainage
Moist
Available space
12 inches-3 feet
NC region
Coastal; Mountains; Piedmont
Growth rate
Rapid
Maintenance
High; Medium
Canopy layer
4 - Herbaceous
Form & Appearance
Habit / form
Erect
Texture
Coarse
Foliage
Deciduous
Leaf color
Green
Leaf type
Simple
Leaf arrangement
Alternate; Rosulate
Leaf shape
Elliptical; Lanceolate
Leaf margin
Lobed
Leaf feel
Prickly
Leaf size
> 6 inches long, 1-3 inches wide
Hairs present
Yes
Leaf detail
The leaf shape changes as the plant ages. Young (seed) leaves are elliptical. Older leaves form a basal rosette that can grow 8-24 inches long and are deeply incised and very spiny. The stem leaves are alternate with pronounced stiff spines along the edges, stiff hairs on the upper surface, and softer white hairs below.
Flower color
Pink; Purple/Lavender
Flower value
Showy
Flower form
Head
Flower shape
Dome
Flower size
1-3 inches
Flower detail
Each flower head contains numerous disc florets. Each disk floret is long and tubular and becomes divided into 5 long thread-like lobes giving it a hair-like appearance. The 1.5-2 inch flowers are pinkish-purple and occur solitary or in groups of 2-3. The bracts are stiff and rigid and have yellow-tipped spines. Blooms June to September.
Bloom time
Summer
Fruit color
Cream/Tan
Fruit type
Achene
Fruit value
Showy
Fruit size
< 1 inch long, < 1 inch wide
Fruit detail
Seeds are produced singly in a flat, brown fruit about 1/10 of an inch long with narrow dark brown stripes. Seeds produce a feathery pappus (similar to dandelion ‘seeds’) which help disperse the seeds.
Stem color
Green; Purple/Lavender
Stem detail
Stout green stems covered in dense white hairs with dark purple veins.
Wildlife & Ecology
Native status
Non-native
Origin
Europe to Siberia and Arabian Peninsula
Distribution
Europe, including Britain, from Scandinavia south and east to N. Africa and W. Asia. Naturalized in North America.
Wildlife value
The seeds are rich in oil, an important food source for seed-eating birds and use the tufts of the seeds for their nests. Members of the genus Cirsium support the following specialized bees: Melissodes (Heliomelissodes) desponsus, Osmia (Helicosmia) chalybea and Osmia (Helicosmia) texana.