North America Non-native Plant

Spiny Cocklebur

Botanical name: Xanthium spinosum

USDA symbol: XASP2

Life cycle: annual

Habit: forb

Native status: Non-native, reproduces and persists in the wild in Canada âš˜ Non-native, reproduces and persists in the wild in the lower 48 states  

Synonyms: Acanthoxanthium spinosum (L.) Fourr. (ACSP5)  âš˜  Xanthium spinosum L. var. inerme Bel (XASPI)   

Spiny Cocklebur: A Weedy Wanderer You’ll Want to Know (But Probably Not Grow) Ever found yourself picking spiky little burs off your socks after a walk through a vacant lot? There’s a good chance you’ve made the acquaintance of spiny cocklebur (Xanthium spinosum), a tenacious annual that’s made itself at ...

Spiny Cocklebur: A Weedy Wanderer You’ll Want to Know (But Probably Not Grow)

Ever found yourself picking spiky little burs off your socks after a walk through a vacant lot? There’s a good chance you’ve made the acquaintance of spiny cocklebur (Xanthium spinosum), a tenacious annual that’s made itself at home across North America despite its foreign origins.

What Exactly Is Spiny Cocklebur?

Spiny cocklebur is an annual forb – basically a non-woody plant that completes its entire life cycle in one growing season. Originally hailing from South America and the Mediterranean region, this sturdy little survivor has hitchhiked its way across continents and now calls much of North America home.

As a member of the sunflower family, you might expect something cheerful and bright, but spiny cocklebur is more like that distant cousin who shows up uninvited and refuses to leave. It’s not particularly pretty, but it’s certainly memorable – especially if you’ve ever had the pleasure of removing its clingy seed pods from your clothing or your dog’s fur.

Where You’ll Find This Prickly Character

This adaptable annual has spread across an impressive range, establishing populations in Alabama, Arizona, California, Colorado, Connecticut, Delaware, District of Columbia, Florida, Georgia, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Maine, Maryland, Massachusetts, Michigan, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Jersey, New Mexico, New York, North Carolina, Ohio, Oregon, Pennsylvania, Rhode Island, South Carolina, Tennessee, Texas, Utah, Virginia, Washington, and West Virginia. It’s also found its way into several Canadian provinces including New Brunswick, Ontario, Quebec, and Saskatchewan.

Should You Plant Spiny Cocklebur?

Here’s the short answer: probably not. While this plant isn’t officially classified as invasive everywhere, it has all the hallmarks of a troublemaker. It spreads readily, isn’t particularly attractive, and those spiny burs can be a real nuisance for both people and animals.

Spiny cocklebur thrives in disturbed areas, vacant lots, roadsides, and waste ground – basically anywhere the soil has been messed with and other plants are struggling. Its superpower is being incredibly tough and drought-tolerant, which sounds great until you realize it means this plant can outcompete more desirable species.

What Does It Look Like?

Spiny cocklebur typically grows as a branching annual that can reach 1-4 feet tall. The leaves are somewhat triangular with toothed edges, and the whole plant has a rather rough, weedy appearance. The flowers are small and unremarkable – greenish and easy to miss. But those seed pods? Those you’ll definitely notice. They’re oval-shaped burs covered in hooked spines that grab onto anything that brushes past.

Growing Conditions (If You Must Know)

This plant is frustratingly easy to grow, which is part of the problem. It tolerates:

  • Poor soils and disturbed ground
  • Drought conditions
  • USDA hardiness zones 4-10
  • Full sun to partial shade
  • Various soil types, though it prefers well-draining conditions

The wetland status across all regions is Facultative Upland, meaning it usually sticks to drier ground but can handle some moisture if needed.

Better Alternatives for Your Garden

Instead of welcoming this prickly visitor into your garden, consider these native alternatives that offer similar toughness without the invasive tendencies:

  • Native sunflowers (Helianthus species) for sunny, dry areas
  • Wild bergamot (Monarda fistulosa) for pollinator support
  • Purple coneflower (Echinacea purpurea) for drought tolerance and wildlife value
  • Black-eyed Susan (Rudbeckia species) for reliable blooms and easy care

If It Shows Up Anyway

Since spiny cocklebur reproduces readily from seed and those burs are excellent at hitchhiking, don’t be surprised if it appears in your garden without an invitation. The best approach is to pull young plants before they set seed, especially after rain when the soil is soft. Wear gloves – those spines aren’t just for show!

Remember, the key to managing any unwanted plant is persistence and prevention. Remove plants before they can produce those clingy seed pods, and you’ll save yourself a lot of trouble down the road.

While spiny cocklebur might not win any beauty contests, understanding these tough, weedy characters helps us become better gardeners and land stewards. Sometimes the most important plants to know about are the ones we choose not to grow!

Wetland Status

The rule of seasoned gardeners and landscapers is to choose the "right plant for the right place" matching plants to their ideal growing conditions, so they'll thrive with less work and fewer inputs. But the simplicity of this catchphrase conceals how tricky plant selection is. While tags list watering requirements, there's more to the story.

Knowing a plant's wetland status can simplify the process by revealing the interaction between plants, water, and soil. Surprisingly, many popular landscape plants are wetland species! And what may be a wetland plant in one area, in another it might thrive in drier conditions. Also, it helps you make smarter gardening choices and grow healthy plants with less care and feeding, saving you time, frustration, and money while producing an attractive garden with greater ecological benefits.

Regions
Status
Moisture Conditions

Arid West

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Atlantic and Gulf Coastal Plain

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Eastern Mountains and Piedmont

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Great Plains

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Midwest

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Northcentral & Northeast

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Western Mountains, Valleys, and Coast

FACU

Facultative Upland - Plants with this status usually occurs in non-wetlands but may occur in wetlands

Spiny Cocklebur

Classification

Group

Dicot

Kingdom

Plantae - Plants

Subkingdom

Tracheobionta - Vascular plants

Superdivision

Spermatophyta - Seed plants

Division

Magnoliophyta - Flowering plants

Subdivision
Class

Magnoliopsida - Dicotyledons

Subclass

Asteridae

Order

Asterales

Family

Asteraceae Bercht. & J. Presl - Aster family

Genus

Xanthium L. - cocklebur

Species

Xanthium spinosum L. - spiny cocklebur

Plant data source: USDA, NRCS 2025. The PLANTS Database. https://plants.usda.gov,. 2/25/2025. National Plant Data Team, Greensboro, NC USA