Guide

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Hitchhiker seeds: burdock, beggarticks and tick-trefoil

September to November

Burdock burs, beggarticks and tick-trefoil pods are seeds built to hook onto fur and clothing, and fall walks along field and trail edges pick them up. Each one is a plant trying to get carried somewhere new before winter.

Why this time of year

These plants set seed in late summer and fall. Burdock burs stay on the dead stalks through fall and winter.

How to notice it

  1. Wear long pants, or pull high socks over your pant legs (light colors show seeds best), and walk the edge of an unmowed field, trail side or roadside.
  2. Stop after a while and check your legs, socks and your dog's coat for seeds that came along.
  3. Sort what you find: round burs covered in tiny hooks (burdock), flat dark seeds with two or more barbed prongs at one end (beggarticks), and flat, fuzzy pod segments (tick-trefoil).
  4. Pick them off by hand or scrape them with a butter knife, because washing leaves most of them stuck. Put native seeds back in the same field, and drop burdock burs in the trash rather than shaking them out somewhere new.

Try this with kids: Count every seed that rode home on your socks, sort them into hooks, prongs and fuzzy pods, then do a tick check with a grown-up.

Word to know: “Achene”: a small dry fruit holding one seed, which is the part of a beggarticks that sticks to you.

Safety

  • After walking through fields, check clothing and skin for ticks.
  • Burdock burs hold tiny bristles that can irritate eyes, skin and breathing, so pick them off pets and clothing with care, don't crush or break burs apart, and keep them away from faces.
  • Stay on the path's edge rather than pushing into tall brush, and wash promptly if you brush against poison ivy.

Sources

  • massaudubon.orgMass Audubon activity sheet: hitchhiker seeds have hooks or barbs that attach to fur; plants disperse before the first big frost; walk unmowed field and road edges in long pants or high socks; release seeds in the same field; check for ticks.
  • plants.ces.ncsu.eduNC State: burdock bracts end in fine hooks forming prickly burs; fruit display fall and winter; non-native; bristles can irritate eyes and skin.
  • umass.eduUMass Extension: Arctium minus introduced biennial; hooked burs stick to fabric and fur.
  • gobotany.nativeplanttrust.orgGo Botany: burdock not native, present in MA in fields and roadsides.
  • gobotany.nativeplanttrust.orgGo Botany: devil's beggarticks native, widespread in MA; achenes have two barbed awns that attach to clothing or fur.
  • gobotany.nativeplanttrust.orgGo Botany: showy tick-trefoil native, widespread in MA; seedpods cling to clothing.
  • fruit.wisc.eduUW-Madison: Bidens bloom August-October; barbed stick-tights attach to fur or clothing.
  • extension.illinois.eduIllinois Extension: washing does not remove most hitchhiker seeds; pick off or scrape with a butter knife.
  • dec.ny.govNY DEC: remove seeds from clothing and dogs; dispose in a garbage can (invasive guidance, applied to burdock only).

Checked against these sources on October 16, 2026.

In the guide for September, October, November

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