Arctium

( ARK - tee - um )

At-A-Glance Information

This is genus includes species of biennial plants commonly known as Burdocks. They are native to Europe and Asia, and several species have naturalized in various climates worldwide. These plants produce dark green, large, coarse leaves and thistle-like flowers that are in bloom from July through October. Seed pods that follow flowers have clinging properties to aid in seed dispersal, and were the original inspiration for the hook and loop fastener. Take care when planting Arctium in the garden, as burs and bristles may cause severe eye, skin, or respiratory problems in humans, pets and livestock. Actiums are also aggressive in the landscape, and have the potential to crowd out other plants.

Arctium Species and Varietals

The genus Arctium is a member of the plant family Asteraceae, and includes 52 species and hybrids. Burdock grows well in USDA hardiness zones 3-10 or Sunset growing zones A1, A2, and 1-26. To find your zone, click here: Zone Map.

Arctium lappa (Arctium leiospermum) (Beggar's Buttons, Greater Burdock, Gobo, Eduble Burdock, Lappa, Thorny Burr, Happy Major)
These plants are native to the Old World, and has naturalized worldwide. It is cultivated as an edible root vegetable plant, and above-ground parts can reach up to 10 feet tall. Leaves are green, and flowers are globe-shaped and purple. These plants bloom from July through September. Taproots can reach up to over 3 feet deep. Considered invasive in North America and Australia.

Arctium minus (Lesser Burdock, Little Burdock, Louse-Bur, Common Burdock, Button-Bur, Cuckoo-Button, Wild Rhubarb)
These plants reach up to 6 feet tall and are bushy. Leaves are up to 20 inches long and are green with wooly undersides. Flowers are pink and similar in appearance to those of Thistle plants. They are native to Europe. Leafstalks, flower stalks, and roots are edible. This species is considered invasive in North America.

Arctium tomentosum (Wooly Burdock, Downy Burdock, Cotton Burdock)
This species was first described by Phillip Miller in 1768, and is native to Eurasia through China. It has naturalized widely in North America, where it is considered an invasive weed. These plants produce erect stems to 6 feet tall and are clothed in green-grey leaves that are quite fuzzy. Flowers are purple-red and bloom from July to September.

Caring for Arctium

Before planting Burdock in the landscape, note that it can be extremely difficult to contain once in the ground and is considered invasive in many regions around the globe; check with local authorities before planting. These plants prefer to receive full sunlight (between 6 and 8 hours of direct sun each day is suggested). They can grow in any type of soil as long as it is well-draining, even if it is poor in nutrients. Water new plantings regularly as they establish a strong root system in their new home. At maturity, Burdock plants are considered to be relatively drought-tolerant, preferring deep but infrequent irrigation. As a general rule of thumb, water whenever the top 2-3 inches of soil feels dry to the touch. Burdock plants are biennial, producing rosettes of foliage in their first year and flowering stems in their second. To control the spread of these often invasive plants, it is suggested that flowering heads are pruned off when they begin to fade so that seeds are not dispersed. Plants will last two years in the garden before needing to be pulled and replaced.

Harvesting Burdock
In Burdock cultivation, seeds are sown in summertime and first-year roots are harvested by late autumn before they become too fibrous. Any longer in the ground, and the roots become unpalatable. The most commonly cultivated species for harvesting is Arctium lappa, or Greater Burdock. To harvest, dig a trench along the side of the planted area, exposing the roots. Carefully lift them out of the ground, and rinse off any dirt or debris. Larger roots can be processed, and smaller roots can be replanted if desired. Burdock roots can be dried, ground, and made into tea, added to soups or stir fries, or simply roasted with spices and other vegetables.

Disclaimer: Information contained on this website is strictly and categorically intended as a reference to be used in conjunction with experts in your area. Foraging and consumption of plant parts should never begin without the guidance and approval of a local plant specialist. The providers of this website accept no liability for the use or misuse of information contained in this website.

Propagation

Arctium can be propagated either by using cuttings or from seed. To ensure that your propagated plant will have the exact same qualities and characteristics as the parent plant, use the cutting method. If you would like to experiment and see what plant you can grow from seed, just keep in mind that it will not necessarily be the same as the parent plant. To propagate your Burdock plant, follow the instructions below:

Propagating Arctium by Seed

Keep in mind that the plant you get from seed will not necessarily mimic all of the characteristics of the parent plant. To propagate by seed, you will need a paper bag, a pot or tray filled with well-draining compost or other organic material, a spray bottle and a fork. If you don't have any potting medium on hand, you can make some. Just mix together equal parts (by volume) moss peat and horticultural-grade sand or grit sand. You will also, after a few weeks, need individual 3-inch pots for each seedling that grows.
Harvest your seeds. The seed pods on these plants are very easy to spot, and will hitch a ride on clothing or pet fur. They contain many small seeds. Cut the flowering head off of the plant completely and place it in a paper bag or other container to avoid spreading seeds where they are unwanted. If seed pods have not opened fully, simply crush to release the seeds.
Water your prepared seed tray or pot filled with soil, and ensure that good drainage is occurring. Place your seeds in your prepared pot or seed tray about a quarter inch to a half-inch under the soil surface. Cover them with soil and water with your spray bottle. Place your tray of seeds in a warm area that receives bright, indirect light. A greenhouse is the most ideal climate, but a planting tray inside a window will do as well. Germination usually takes 7-14 days from sowing. Once you begin to see seedlings sprout and they are able to be handled, transplant them to their own individual 3-inch pots, filled with the same potting medium as described in Step 1. Loosen the seedlings from the potting medium by digging down with the tines of your fork about an inch and a half, gently working the seedling up until it is out. Then, replant the seedling in its individual pot.
Keep the seedling's potting medium moist, but not wet, by spraying the soil with your spray bottle. Keep your new plant in an area with bright light (though not direct sunlight) and temperatures between 55 and 70 degrees Fahrenheit. Ensure that the soil stays moist, but not wet, until the next spring (after the danger of frost has passed), when you can transplant it to its new home.

Propagating Arctium by Division
This type of propagation is relatively simple; you will need a clean shovel, mulch, fresh soil (any kind will do, though it does need to be well-draining), compost, and pots (12 inch pots will do, and these are only necessary if you will be saving divided plants for transporting elsewhere). Division is best done in fall when the plants are harvested, and needs to be done every four to five years regardless of whether you have the goal of propagating to avoid them spreading into areas where they are unwanted. To propagate by division, follow these steps:

Gather your materials. Using a shovel, dig up your existing plant. Start from the outside and work your way in to avoid damaging the tuber roots. Once you have worked them up out of the ground, lay them out.
Separate your plant roots into segments, ensuring that each one has at least one thick tuberous section.
Prepare your pot(s) or new planting site(s) with amended, well-draining soil. You can either bring in new soil or simply amend your existing soil with compost to complete this task. Then, plant your divided tubers about an inch under the soil surface and water thoroughly.
Apply a thick layer of mulch over the new planting to protect it from cold weather as it acclimates to its new home. Then, enjoy watching it sprout.

A Burdock seed pod.

Burdock seeds.

Problems and Pests

Arctium plants are notoriously difficult to control in garden spaces; they readily escape landscapes and naturalize in disturbed soils, empty parking lots, parks, roadsides, fields, and pastures. They compete well with native plants, and are extremely difficult to eradicate once they are in an area; their deep taproots can re-sprout easily from small pieces left behind. Burdock plants are susceptible to developing issues with the following pests and diseases in the landscape: