Bush Honeysuckle

The arching red-berried shrub that fills the understory of half the woodlots in the Midwest and Northeast - first to leaf out, last to drop, and the reason nothing grows beneath it. It is also the toxic look-alike foragers mistake for autumn olive. Never plant it.

How to recognize it: opposite oval leaves, paired flowers and paired red berries, hollow pith in older stems, and a leaf season that starts and ends weeks outside everything around it. Plus the two names it shares with plants that are not invasive at all.

You should never plant this, so identification is the point. Look for an arching, multi-stemmed shrub with simple, opposite, oval, pointed leaves; paired tubular flowers from the leaf axils in May and June; and paired translucent red berries from late summer into winter. Old bark is grey-brown and shreds in vertical strips. The confirming test is the pith: cut a stem thicker than a pencil and the invasive honeysuckles are hollow and brown inside, where most native shrubs are solid and white. The species differ in detail — Amur is the tallest and most tree-like with long-pointed leaves, Morrow's is grey-downy, Tatarian is smooth with pink flowers, and Bell's is intermediate — but they are controlled identically, so you do not have to settle the species to act.

Two naming traps are worth clearing up. First, the native shrubs also called bush honeysuckle — Diervilla lonicera and its relatives — are perfectly good plants: low, suckering, yellow-flowered, with dry capsules instead of red berries and no hollow pith. Do not tear one out. Second, the red-berry confusion with autumn olive, which is the one that gets people sick. Both are scrubby shrubs of old fields and edges with red fruit in fall. Autumn olive has alternate leaves with distinctly silvery-scaly undersides and berries flecked with silver, and its berries are edible. Bush honeysuckle has opposite leaves, no silver anywhere, hollow pith, and berries that make you vomit. Leaf arrangement takes two seconds and settles it.

How it spreads: enormous berry crops moved by birds for miles, seed that germinates in deep shade, and stumps that resprout into a ring of stems - which is why cutting alone rebuilds the thicket thicker than before.

Bush honeysuckle spreads overwhelmingly by bird-dispersed seed, and it is very good at it. A mature Amur honeysuckle can carry many thousands of berries, they ripen when migratory and resident birds are feeding heavily, and they hang on into winter when little else is left. Seed passes through and germinates readily — crucially, in deep shade as well as in the open, which is why closed-canopy woodlots fill in from the inside rather than only from the edges. Seedling density under a fruiting shrub or a favored perch can run into the hundreds per square yard.

The second mechanism is resprouting. Cut or mow a bush honeysuckle and it returns from the root crown as a ring of vigorous stems, typically denser than the single shrub you removed. It also layers where low branches rest on soil. This is the reason so many well-meant volunteer workdays leave a site worse off a year later: the cutting was real work, the plant simply treated it as pruning. Effective control has to remove the seed source, kill the root crown, and then hold the ground that clearing opens up — because the seed bank under an old stand will restock bare soil within two seasons.

Control, not care: pull small shrubs by the root, cut-stump-treat larger ones in the dormant season using the late-leaf window, take out fruiting shrubs first, and plant the gap the same season you make it.

For bush honeysuckle, care means removal, and the method should scale with stem size. Under about an inch at the base: pull it. Moist spring soil gives up seedlings and small shrubs whole, and a weed wrench or lever tool handles the next size up. This is real, chemical-free progress on small infestations — just get the root crown, because a snapped stem comes back. Larger shrubs: the standard method is cut-stump herbicide treatment. Cut low, apply to the fresh cut surface within minutes before it seals, and work in the dormant season, late fall through winter, when the plant is moving reserves down and the natives around it are asleep. Use a product whose label lists the site you are treating and follow that label exactly — the label is the legally binding instruction. If you are working in a floodplain, along a stream, or anywhere water stands, the product must be labelled for aquatic sites, and many states require a permit or a licensed applicator for that work.

Two pieces of sequencing matter more than technique. Take the fruiting shrubs first. Clearing seedlings while a berry-laden parent still stands is wasted effort; kill the seed source, then work down through the sizes. And plan the replanting before you clear, because a stripped thicket leaves bare, shaded, seed-loaded ground that reinvades fast. Put something in it the same season — spicebush, arrowwood or blackhaw viburnum, serviceberry, elderberry, chokeberry, or a woodland seed mix suited to your region — and mulch what you cannot plant. Then walk the site each spring for several years pulling the seedling flush. For a large woodlot, your county extension office or a local invasive-plant partnership can usually advise on region-specific timing and, in some places, help with equipment.

Not a food - the berries are mildly toxic to people and cause vomiting and diarrhea. They are not much better for the birds that spread them: honeysuckle fruit is sugary and low in fat, poor fuel for migration compared with the native shrubs it replaces.

Bush honeysuckle is not edible. The paired red berries contain saponins and other compounds that cause vomiting and diarrhea, and while a berry or two is unlikely to do lasting harm, a handful will make a child or a dog genuinely sick. Keep them out of reach, and if someone eats them call Poison Control, or a veterinarian for a pet. The berries are the reason this shrub deserves a page at all for anyone who forages: it is the plant most often mistaken for autumn olive, which is edible. The rule is opposite leaves and hollow pith mean do not eat; alternate leaves with silvery undersides and silver-flecked fruit mean autumn olive.

The wildlife story is more interesting than it looks. Birds eat the berries eagerly, which is often cited as a benefit — it is not. Honeysuckle fruit is high in sugar and low in fat, and research comparing it with native fruits has found it a poor energy source for birds building reserves for migration; birds feeding heavily on it can also end up with visibly redder plumage from its pigments. Meanwhile the shrub replaces the native fruit — dogwood, viburnum, spicebush, elderberry — that is fat-rich and actually fuels the flight. Add the bare, shaded ground beneath a stand, where the spring wildflowers and tree seedlings used to be, and the ecological ledger is clearly negative. The most nutritious thing this plant can do for wildlife is be replaced by natives.

Introduced from Asia and Eurasia through the 1800s as hardy ornamental hedging, then distributed by the millions for wildlife food, erosion control and highway screening well into the 1980s - the plantings that seeded the invasion are still standing.

These shrubs arrived as ornamentals: Tatarian honeysuckle from Eurasia in the 1750s, Morrow's and Amur honeysuckle from eastern Asia through the 1800s, all valued as tough, fast, hardy hedging with pretty flowers and heavy fruit. That would have been bad enough, but the real damage came later. Through the middle of the twentieth century, conservation and highway agencies propagated and distributed them by the million for wildlife food and cover, erosion control, strip-mine reclamation, and highway screening. Improved selections were released specifically for the wildlife-planting market, and the shrub was still being recommended in some programs into the 1980s.

Every one of those plantings became a seed source, and the birds did the rest. By the 1990s bush honeysuckle was recognized across the Midwest and Northeast as one of the most abundant invasive shrubs on the continent, and the agencies that once handed out seedlings now run removal programs. Several states have since banned its sale — Massachusetts, Connecticut, New Hampshire, Ohio and Illinois among them — and Wisconsin restricts it; the rules differ by state and sometimes by species, so check your own list. The pattern is by now familiar from autumn olive, multiflora rose and Callery pear: tough, fast and good for wildlife turned out to describe an invader.

Is it the invasive one or a native? Can I eat the berries? Why did it come back as ten stems? Why is the ground bare? The practical answers, including the autumn-olive discriminator and why clearing without replanting fails.

Is this an invasive bush honeysuckle? Opposite oval leaves, paired tubular flowers, paired red berries, shreddy grey bark, and — the confirming test — hollow brown pith in stems thicker than a pencil. If it is green in early April when the woods are bare, that is close to diagnostic. But my field guide says bush honeysuckle is native. Both are true: the native Diervilla shrubs share the common name. They are low and suckering, with yellow flowers, dry capsules rather than red berries, and solid pith. Do not remove those. Can I eat the red berries? No — they are mildly toxic and cause vomiting and diarrhea. If you were reaching for them thinking autumn olive, check the leaves: alternate with silvery undersides and silver-flecked fruit is autumn olive; opposite leaves and hollow pith is honeysuckle. How do I remove it? Pull anything up to about an inch thick from moist soil, root crown and all; cut-stump-treat larger shrubs in the dormant season. I cut it and now there are ten stems. That is what cutting alone does — it resprouts from the root crown. Treat the stump, or pull the crown out. Nothing grows under it. Correct, and that is the main harm: it leafs out first and drops last, so it takes the light the spring wildflowers need. I cleared it and it came straight back. The seed bank under an old stand refills bare ground within two seasons — plant and mulch the gap the same season you clear it. What should I plant instead? Spicebush, arrowwood or blackhaw viburnum, serviceberry, elderberry, or chokeberry.

Invasive across roughly zones 3-8, worst in the Midwest, Ohio Valley, Northeast and mid-Atlantic; extremely cold-hardy, shade-tolerant, and indifferent to soil - its edge is phenological rather than climatic.

Bush honeysuckles are invasive across roughly zones 3-8, with the heaviest infestations in the Midwest and Ohio Valley and severe problems through the Northeast, mid-Atlantic and upper South. They are extremely cold-hardy — Tatarian and Morrow's run well into the northern plains and New England — and they tolerate almost any soil, from dry roadside fill to floodplain silt. Amur honeysuckle is the most aggressive through the warmer, moister center of that range.

Their competitive edge is phenological rather than climatic, which is worth understanding because it is also the control window. They break bud two to four weeks before the native canopy and hold green leaves weeks after it drops, capturing light in the shoulder seasons that spring ephemerals and tree seedlings need. That advantage grows in regions with long, mild shoulder seasons, and it gives you a selective opportunity: late fall and early spring foliar treatment, when the honeysuckle is the only green thing in the understory, targets it while natives are dormant. Wherever you are in its range, the practical guidance is the same — walk the woods when everything else is bare, map the green, take the fruiting shrubs first, and plant what you clear.