Hairy Bittercress
Broadleaf annual weed
Hairy bittercress is a small, fast annual weed that is especially familiar in pots, greenhouse benches and recently planted borders. It often completes its life cycle before it is noticed. Ripe seed pods burst when brushed, sending seed surprisingly far, so removing plants before pods ripen is the key task.
How to identify it
Plants form a low rosette of divided leaves, then produce slender upright stems 5 to 30 cm tall. Each leaf has several rounded leaflets along a central stalk, often with a larger terminal leaflet. Small white flowers with four petals appear at the stem tips. Long, narrow green seed pods follow and spring open when ripe or touched. Fine hairs may occur on stems and leaves. The root is a small, shallow taproot, usually easy to lift from moist compost.
Where it grows
It grows across the UK in moist, open soil, particularly in containers, greenhouse borders, cracks in paving and freshly cultivated beds. Germination is common in spring and autumn, though sheltered sites can support plants in most months. It favours damp compost, regular watering and the undisturbed corners of pots, trays and raised beds.
Why it is a problem
A few overlooked plants can seed a large area because their pods disperse seed abruptly. It competes with newly sown vegetables, young ornamentals and pot-grown plants, where space and moisture are limited. Repeated germination also makes beds look untidy and can turn routine pot maintenance into a continuing job.
How to control it
Pull plants before the flowers develop into full seed pods, taking care not to brush ripe pods. Hoe young seedlings in dry weather, leaving them exposed to dry before rain returns. Hand-weed containers and greenhouse edges regularly, removing seedlings with their shallow roots. Apply mulch to open beds once crops are established, and cover vacant soil to exclude light. Inspect pots, trays and newly bought plants often, since compost is a common starting point.
Commonly confused with
It resembles other bittercresses and small cresses, especially wavy bittercress. Hairy bittercress usually has a compact rosette, white four-petalled flowers and narrow explosive pods. Young plants can also resemble small mustard seedlings, but their neatly paired leaflets are a useful clue.
Hairy Bittercress: frequently asked questions
How do I identify hairy bittercress?
Plants form a low rosette of divided leaves, then produce slender upright stems 5 to 30 cm tall.
How do I get rid of hairy bittercress?
Pull plants before the flowers develop into full seed pods, taking care not to brush ripe pods.
Where does hairy bittercress grow?
It grows across the UK in moist, open soil, particularly in containers, greenhouse borders, cracks in paving and freshly cultivated beds.
General guidance for UK gardens and allotments, focused on prevention and non-chemical control. For a confirmed identification, the RHS or a local garden centre can help. Page updated 19 Sep 2026.