Bittersweet Nightshade: A Poisonous Plant for the Damp Shade of the Garden

Growing bittersweet nightshade – well-drained to muddy substrate, shade only, generous watering, damp conditions

In brief: Bittersweet nightshade (Solanum dulcamara) is a perennial with purple flowers and red berries that grows in shade on damp to boggy soil, most often by water or in scrub. The whole plant contains poisonous alkaloids, the berries being the most dangerous – so it belongs rather at the edge of the garden, out of reach of children and pets, than in a bed next to a sandpit.

Position	shade to partial shade
Soil	well-drained to muddy, permanently damp
Watering	generous, the soil must not dry out
Toxicity	the whole plant, most of all the berries (they contain solanine)
Risk group	children, dogs and cats – attracted by the red berries

Bittersweet nightshade (woody nightshade, Solanum dulcamara) belongs to the nightshade family, like the tomato or the potato. Unlike them, however, the whole plant is poisonous, so it is good to be able to recognise it in the garden – whether because you want to grow it as an undemanding climbing perennial for damp shade, or, on the contrary, because it has grown up on its own and you want to know how to handle it safely.

In the wild bittersweet nightshade grows on the banks of streams and ponds, in ditches, at the edges of woods and in scrub – that is, wherever there is constant moisture and at least partial shade. It requires the same conditions in the garden.

How to recognise bittersweet nightshade

Bittersweet nightshade is a semi-deciduous subshrub with climbing or trailing stems that grows to 1–2 metres. The purple flowers with a distinctive yellow centre resemble a potato flower and bloom from May to August. After flowering it sets ovoid berries, which gradually change colour from green through yellow to bright red – at this stage they look most tempting to children and animals.

The leaves of bittersweet nightshade are alternate, ovate to heart-shaped, often with one or two small side lobes at the base. The stems are woody at the base and herbaceous at the tips, which makes the plant look half like a shrub and half like a climber. In winter the above-ground part dies back partly or completely, and in spring it shoots again from overwintering parts near the ground.

Position, soil and care

Bittersweet nightshade suits a shady to partially shaded spot with well-drained but permanently damp to muddy soil – the edge of a garden pond, a damper corner by the fence or the shade under shrubs is ideal. Drought and full sun do not suit it; on the contrary, dried-out or parched soil weakens the plant. Feeding is usually not needed; on richer soil it grows lushly enough by itself and, without further intervention, will last in the same place for many years.

Why bittersweet nightshade is poisonous and what to watch out for

The whole plant contains alkaloid glycosides, above all solanine and related substances. Most of them are in unripe green berries and in the leaves, the least in fully ripe red fruits – but even those are risky, especially for small children. Poisoning shows itself as a burning sensation in the throat, nausea, vomiting, diarrhoea and a rapid heartbeat. Unripe berries taste sweetish, ripe ones on the contrary unpleasantly bitter, which is a partial natural protection against eating them in larger quantities.

If you have small children or animals in the garden that tend to taste everything they find, plant bittersweet nightshade out of their reach, for example behind a fence by a pond to which they have no free access, and remove the berries continually before they ripen.

Traditional use and why it is not recommended today

In folk medicine the dried spring shoots of bittersweet nightshade were traditionally collected and used externally, among other things for their anti-inflammatory properties. Given the high content of poisonous alkaloids and the narrow margin between a safe and a risky dose, self-treatment with bittersweet nightshade is not recommended today, because the difference between a usable and a harmful amount is hard to estimate in home preparation. If the plant interests you from this point of view, it is appropriate to consult a doctor or herbalist, not to experiment at home.

Propagation and placement in the garden

Bittersweet nightshade is most easily propagated by cuttings or by dividing the clump in spring, or by sowing seeds from ripe berries into damp substrate. Because it is a fast-growing and in places invasive climber, it suits the edge of the garden or a pond, where it has enough space and will not compete with cultivated plants. If you want to keep it smaller, simply shorten it in spring by a third to a half of the length of the shoots.

Similar poisonous plants by water and in shade

Bittersweet nightshade is not the only plant that commonly appears in damp and shady places in the garden and can be risky. Before you start weeding or let children go to the water unsupervised, it is useful to know other similar species too.

Plant	Risky part	Typical symptoms
Bittersweet nightshade (Solanum dulcamara)	the whole plant, most of all the berries	irritation of the digestive tract, rapid heartbeat
Autumn crocus (Colchicum autumnale)	the whole plant, especially the seeds and corms	severe digestive problems, risk even with a small amount
Deadly nightshade (Atropa belladonna)	the whole plant, the berries are sweet	dilated pupils, confusion, cardiac arrhythmia
Monkshood (Aconitum napellus)	the whole plant	tingling, numbness, heart and breathing problems

All these plants are among the native poisonous species that can be met in damper and shadier places in the garden or at its edge. The basic rule is the same for all of them: do not eat unknown berries and leaves, and explain to children that whatever grows in the garden is not automatically for eating.

Frequently asked questions

Is bittersweet nightshade dangerous for dogs and cats?

Yes, eating the berries or leaves can cause vomiting, diarrhoea and general listlessness. If an animal has chewed the plant or swallowed berries, contact a vet.

How does bittersweet nightshade differ from the tomato, when they belong to the same family?

The tomato has been bred to be free of the high alkaloid content in its fruits, bittersweet nightshade has not – which is why its berries, unlike ripe tomatoes, are poisonous throughout.

Can bittersweet nightshade be grown safely in a garden with children?

It can, if you place it out of their reach and keep removing the berries. For small children, however, it is more sensible to choose another, non-poisonous perennial for damp shade.

What should I do if I suspect poisoning by bittersweet nightshade?

Do not induce vomiting. Contact the Toxicological Information Centre or a medical emergency service and state how many berries or what amount of the plant may have been swallowed, or take a sample of the plant with you to make identification easier.

Is bittersweet nightshade protected in the Czech Republic, or on the contrary invasive?

Bittersweet nightshade is not specially protected in the Czech Republic or regulated as an invasive species, but in damp habitats it spreads spontaneously and easily, so it is good to keep an eye on where it expands.

Does bittersweet nightshade have any use in the garden?

Yes, the small purple flowers are visited by bumblebees and other pollinators, and birds like to seek out dense growth for shelter. If you plant it out of the reach of children and animals, it can also benefit garden biodiversity and be a good complement to other moisture-loving perennials on a shady edge of the plot.

Sources

Updated: 10 October 2026