One of the most common things we hear from Lake County property owners is some version of this: "I thought that shrub was supposed to be here." Buckthorn is so pervasive in the Illinois landscape that many people assume it's native. It isn't — and the difference matters enormously for the health of your property.
This post walks through how to tell buckthorn apart from native shrubs it's commonly confused with, explains why buckthorn causes ecological harm that native shrubs don't, and offers native alternatives that provide real habitat value.
Why Buckthorn Gets Mistaken for Native Plants
Buckthorn has several characteristics that make it easy to overlook or misidentify:
- It's everywhere. When a plant occupies nearly every woodlot in a region, it starts to look "normal."
- It has dark berries in late summer and fall — similar to several native species with wildlife-friendly fruit.
- Its leaves are oval with toothed margins, a shape shared by many native shrubs.
- Young plants look similar to native shrub seedlings before their distinctive features develop.
The result is that many property owners walk past dense buckthorn thickets for years thinking they're looking at native vegetation. By the time the problem is obvious, the infestation is substantial.
The Key Identifiers That Give Buckthorn Away
Before comparing to specific natives, a quick refresher on what sets buckthorn apart:
Common buckthorn (Rhamnus cathartica)
- Sharp thorn at the tip of most branches (the most reliable field identifier)
- Orange-yellow inner bark when a small stem is scratched
- Leaves hold their dark green color well into November, long after native trees have gone dormant
- Dark berries in clusters along the stem in late summer/fall — mildly toxic to humans and pets
Glossy buckthorn (Frangula alnus)
- No thorns — often leads to confusion with native shrubs
- Distinctive white horizontal markings (lenticels) on young bark
- Orange inner bark when scratched (same as common buckthorn)
- Glossy, smooth-margined leaves (no teeth), slightly elongated
- Berries ripen through stages of red, purple, and black simultaneously on the same branch
For a more detailed guide, see our post on how to identify buckthorn on your property.
Buckthorn vs. Native Shrubs: Side-by-Side
Chokecherry (Prunus virginiana)
Chokecherry is a native Illinois shrub that can be confused with glossy buckthorn in late summer when both have dark berries. Here's how to tell them apart:
| Feature | Chokecherry | Glossy Buckthorn |
|---|---|---|
| Berries | Hang in elongated clusters (racemes) | Small clusters along stem |
| Leaves | Oval with sharply toothed margins | Smooth-margined, glossy |
| Bark | Gray-brown with horizontal lenticels | Also has lenticels, but more pronounced |
| Thorns | None | None |
| Inner bark | Reddish-brown, bitter smell | Orange-yellow |
Chokecherry is a valuable native — birds love the berries, and its spring blossoms support pollinators. If you're not sure what you have, scratch a small stem: the bitter, almost cherry-like smell of chokecherry inner bark is quite different from the neutral-to-slightly-acrid smell of buckthorn.
Elderberry (Sambucus canadensis)
Elderberry is a fast-growing native shrub with dark berries that's occasionally confused with buckthorn in late summer. The differences are quite distinctive:
- Elderberry has compound leaves (multiple leaflets on a single stem). Buckthorn always has simple, single leaves.
- Elderberry grows in open, moist areas and produces flat-topped clusters of white flowers in early summer. Buckthorn has small, inconspicuous flowers.
- Elderberry stems are hollow inside with soft, pithy centers. Buckthorn stems are solid.
If the leaves are compound, it's not buckthorn.
Serviceberry (Amelanchier spp.)
Serviceberry (also called Juneberry) is a native shrub or small tree with round, purplish-black berries that ripen in early summer. It's sometimes mistaken for young buckthorn:
- Serviceberry blooms with white flowers in early spring before leaves fully emerge. Buckthorn has no showy flowers.
- Serviceberry berries ripen in June. Buckthorn berries ripen in late August and September.
- No thorns, no orange inner bark.
Serviceberry is one of the most wildlife-valuable native plants in the Midwest — birds eagerly consume the berries, often stripping a whole shrub within days of ripening.
Wild Plum (Prunus americana)
Wild plum can look somewhat similar to common buckthorn in its branching structure, and both have thorny stems. Key differences:
- Wild plum has true spurs (short, stubby branches that end bluntly), not sharp terminal thorns like buckthorn.
- Wild plum has showy white blossoms in April before leaves emerge.
- Wild plum berries are round, red or yellow, and relatively large — nothing like buckthorn's small black clusters.
Nannyberry (Viburnum lentago)
Nannyberry is a large native shrub with clusters of dark blue-black berries in fall that can superficially resemble buckthorn from a distance. Up close:
- Nannyberry has opposite leaves with a distinctive reddish petiole (leaf stem). Buckthorn leaves are mostly opposite but the petiole is green.
- No thorns, no orange inner bark.
- Nannyberry berries form in flat-topped clusters, while buckthorn berries are in small clusters along the stem.
- Nannyberry has warty gray bark on older stems — quite different from buckthorn's scaly brown bark.
The Ecological Difference: Why It Matters Which Shrub Is on Your Land
This isn't just an identification exercise. Native shrubs and buckthorn have dramatically different ecological impacts on your land.
Native shrubs support wildlife. Chokecherry, elderberry, serviceberry, and viburnum are all deeply embedded in the local food web. Their berries are consumed by dozens of bird species and mammals. Their flowers feed native bees and pollinators. Their leaves host the caterpillars of native butterflies and moths.
Buckthorn undermines the food web. Research from the University of Illinois and other institutions has documented how buckthorn infestations reduce native plant diversity, decrease the abundance of native tree seedlings, and simplify the forest understory. A buckthorn-dominated understory supports fewer insects, which means fewer birds. It's a cascade effect.
Buckthorn alters soil chemistry. Emodin, a compound in buckthorn leaves and berries, inhibits the germination and growth of competing native plants. Over time, buckthorn-infested soils become less hospitable to native species — which is one reason restoration after buckthorn removal sometimes requires active replanting rather than just waiting for natural recovery.
Buckthorn spreads to neighboring land. Native shrubs stay where you plant them (or expand naturally in their range). Buckthorn seeds are spread by birds and can colonize neighboring properties and natural areas. Your infestation is a seed source for your neighbors' land.
What to Plant Instead
After buckthorn removal, the priority is getting native plants established before buckthorn seedlings fill the void. Our native plant restoration guide covers this in depth, but here's a quick summary of native shrubs that thrive in Lake County:
- Nannyberry viburnum — tolerant of shade and varied moisture, excellent for woodland edges
- Elderberry — fast growing, very effective at quickly filling gaps, excellent wildlife value
- Wild plum — tough and vigorous for open, sunny areas; birds and mammals love the fruit
- Serviceberry — exceptional wildlife value, beautiful spring bloom, works at woodland edges
- Dogwood species — Cornus racemosa (gray dogwood) and Cornus amomum (silky dogwood) are excellent natives for moist areas
For restoration to succeed, native planting should happen in the same season as removal to get ahead of the buckthorn seed bank. Several of these species are also eligible for cost-share through Riverwoods' Native Seeding program — see our grants page for details.
Still Not Sure What You're Looking At?
If you have shrubs on your property that you're not sure about, we're happy to help with identification. Send us photos or reach out to schedule a walkthrough — we can confirm whether what you're seeing is buckthorn or a native, and give you an honest assessment of next steps either way.