What is bittersweet nightshade?

Good bittersweet nightshade identification starts with knowing it is a scrambling, semi-woody perennial vine in the same family as tomatoes and potatoes. It came over from Europe and Asia and now turns up in hedgerows, fence lines and overgrown corners all over Pennsylvania.

It is not the most aggressive weed you’ll deal with, but it is one worth noticing. The berries are poisonous, they look a lot like tiny tomatoes, and they hang right at a child’s eye level in a shrub bed or along a fence.

Bittersweet nightshade identification: what to look for

The flowers give it away. Each bloom is about half an inch across, with five purple petals swept backward around a pointed yellow cone in the center. You’ll see them in loose clusters from late spring right through summer, often on the same plant as ripening fruit.

• Leaves: Dark green, sometimes purple-tinged, alternate on the stem. Many leaves have one or two small lobes or ‘ears’ at the base, but some are plain and heart-shaped, so check several.
• Berries: Oval, about a third of an inch long, hanging in drooping clusters. They start green, turn orange, then ripen to a glossy red.
• Stems: Thin and green when young, becoming woody and tan near the base. They lean on and weave through whatever is nearby.
• Smell: Crush a leaf and it smells rank and unpleasant.

The old stems often die back partway over winter and push out new growth each spring from the woody base, so a patch can look dead in March and be thick again by June.

Where it grows in Pennsylvania

Bittersweet nightshade likes moisture and a bit of shade. In central PA it shows up along creek banks and drainage ditches, in wet woods edges, in brushy fence rows of old farm fields, and in shrub beds along the north side of a house where the soil stays damp.

Birds eat the berries and drop the seeds under wherever they perch, which is why you so often find it growing up through a hedge, a fence or a foundation planting. Wet, poorly drained spots in a yard are a favorite.

Bittersweet nightshade look-alikes

The name causes most of the confusion. Oriental bittersweet is a completely different plant, a true woody vine with round toothed leaves and orange-and-red capsules in fall. It has no purple flowers.

Eastern black nightshade is a low, bushy annual with small white flowers and black berries. Horsenettle stands upright, is covered in prickles and makes yellow berries. If your plant climbs, has purple star flowers and red berries, it’s bittersweet nightshade.

How to get rid of bittersweet nightshade

For a few plants, pulling it yourself is the right answer. The roots are fairly shallow, so it comes out well when the soil is moist in spring.

• Hand removal: Wear gloves. Follow each stem back to its base and dig out the crown and as much root as you can. Leftover root pieces and stems lying on wet ground can root again, so bag everything, especially stems with berries. Don’t compost it.
• Cutting: On a large tangle, cut the stems down and keep cutting the regrowth. That alone weakens it, and it sets you up for a cleaner follow-up.
• Cultural: Thick mulch over a cleared bed helps keep seedlings and root sprouts from coming back. If the area stays soggy, fixing the drainage takes away the conditions it loves.
• Chemical: Broadleaf herbicides containing triclopyr, or glyphosate for spot treatment where nothing else will be hit, are commonly used on the leafed-out vines in summer. Glyphosate will injure any plant it touches, so keep it off your shrubs. Read and follow the product label (the label is the law), and make sure the product is labeled for your site, whether that is a lawn, a landscape bed or near a stream.

Near creeks and ditches, only products labeled for use near water can be used. Applying herbicide for hire in Pennsylvania requires a PA Department of Agriculture pesticide applicator certification, so larger or streamside jobs belong with a licensed lawn-care or vegetation-management company. Expect to go after resprouts for at least a season or two, and check again the following spring.

Keeping it from coming back

Because birds keep planting new seeds, the goal is catching seedlings early. Walk your fence lines and shrub beds each spring and pull anything with that telltale leaf before it gets woody.

Keep beds mulched about two to three inches deep, and thin out overgrown shrubs so you can actually see the ground underneath. A damp, neglected corner is exactly where this vine hides, so a cleaner, drier, better-drained yard is your best long-term defense.

Questions we get about bittersweet nightshade

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Eastern Black NightshadeSolanum ptycanthumHorsenettleSolanum carolinenseOriental BittersweetCelastrus orbiculatus