Pollinator Pockets West Roxbury, MA
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Invasive Species

Common Buckthorn

Rhamnus cathartica

A thorn-tipped shrub-tree that leafs out early and holds its leaves late, shading the forest floor bare.

Why it's harmful How to ID it How to remove it
Common buckthorn foliage — glossy, finely toothed leaves whose veins curve to follow the leaf edge toward the tip
Photo: NY State IPM Program at Cornell University via Wikimedia Commons · CC BY 2.0

📝 Draft content — written for your review. Verify the identification and removal details before publishing.

Why it’s harmful

Common buckthorn is a large shrub or small tree that has invaded woodlands, hedgerows, and yards throughout the Northeast.

  • It leafs out earlier in spring and holds its leaves later in fall than almost any native — casting deep shade that starves out native wildflowers and tree seedlings beneath it.
  • It forms dense thickets that crowd out the native plants pollinators and birds rely on.
  • Birds eat its abundant berries — which have a strong laxative effect (hence cathartica) — and spread the seeds far and wide.
  • It’s an alternate host for crop pests, including soybean aphid and oat crown rust, and can change the nitrogen chemistry of the soil.

How to ID it

  • Form: a shrub or small tree, often multi-stemmed, up to about 20–25 feet.
  • Thorns: twigs frequently end in a short, sharp spine between the two terminal buds — a key feature.
  • Bark: dark gray-brown with prominent pale dots (lenticels); scratch it and the inner bark is bright orange.
  • Leaves: oval, finely toothed, with 3–5 pairs of veins that curve to follow the leaf edge toward the tip (arcuate venation) — very distinctive. They stay glossy green well into late fall.
  • Berries: clusters of small black berries in fall on female plants.

Look-alikes: Native cherries and plums, and the related glossy buckthorn (Frangula alnus) — which has untoothed leaves and lacks the twig spines.

📸 1 photos to help you recognize it in different settings and seasons.Click any photo to enlarge and browse.

How to remove it

A great time to tackle buckthorn is late fall, when its leaves stay green long after natives have dropped — making it easy to spot and avoid harming everything else.

  1. Seedlings & small plants: pull or dig them when the soil is moist; a weed wrench helps with larger stems.
  2. Don’t just cut it. Cut stumps resprout vigorously.
  3. Larger plants: the most reliable kill is a cut-stump herbicide treatment (triclopyr or glyphosate) on the fresh cut, ideally in late summer or fall.
  4. Bag the berries so birds can’t spread them.
  5. Replant or mulch the cleared area to discourage re-invasion, and monitor for several years as the seed bank empties.

Sources and local guidance vary — when removing invasives, follow the latest advice from groups like the Massachusetts Invasive Plant Advisory Group (MIPAG) and your local conservation commission.