Bryony refers to two British native plants, white bryony (Bryonia dioica) and black bryony (Tamus communis). While unrelated, they share similar characteristics, including a vigorous climbing habit and tuberous roots. They're commonly found in hedgerows and the woodland edge, but are also found in gardens, where their extremely vigorous growth causes problems. The weight of their stems can smother growth of other plants, and therefore require control.
How to identify bryony
White bryony is a cucurbit, and is therefore related to courgettes, pumpkins and melons. It's a scrambling climber with large, five-lobed leaves, climbing tendrils, and greenish summer flowers, followed by red berries.
Black bryony is our only native plant that's in the yam family, Dioscoreaceae. It's a twining climber with heart-shaped leaves and no tendrils, and bears smaller, yellow-green flowers, followed by red berries.
The berries of both species are conspicuous and hang from dead stems throughout autumn.
Is bryony poisonous?
All parts of black and white bryony, including their berries, are poisonous. White bryony may also cause skin irritation so wear gloves when handling the plant and wash your hands afterwards.
How to control bryony in your garden
Bryony is introduced to gardens by birds, and is therefore often found growing in hard-to reach areas, such as among tree roots or beneath shrubs. For this reason, digging out is not always an option. It's worth trying though – it's best to tackle bryony plants when young, if left, both plants can develop large tubers and be almost impossible to dig out. However, digging out even a section of tuber can be enough to kill bryony, so try this first if possible. If you're unable to completely dig it out, persistently and regularly cutting back growth may be enough to eventually kill it.
If using weedkiller, bear in mind that its key ingredient, glyphosate, is extremely toxic and has been linked to cancer cases in humans. Studies have shown that it also destroys soil microbes and affects earthworms. Use with caution: wear protection, use as little as possible and ensure no other plants are affected from accidental contact such as spray drift. To do this, lay the leaves and stems on a hard surface, such as a path, and then spray or paint with a glyphosate-based herbicide. One application may not be enough to kill bryony so you may need to repeat the process a few times. The best time of year to apply weedkiller is summer to early autumn.