Insects find lifeline in the busiest of busy lizzies

Pop, pip, pop ... seedheads of Himalayan balsam are bursting in tiny explosions. The flower heads are chandeliers of red-green, glassy, pendants, which open into lipped, lobed, bulbous flowers like orchids from cerise to shell pink.

Each of these has a bee’s backside sticking out of it. When they’re pollinated and the petals crinkle and fall, the seedhead grenades are formed.

The first of these popped in Britain in 1839 when the plant was grown in gardens from seed collected in the Himalayas. Since then Himalayan balsam (Impatiens glandulifera), the busiest of busy lizzies, has colonised stream banks, river valleys and damp patches all over the country.

Sometimes this spread has been due to natural encroachment – the seeds can land seven metres away and are viable for two years. Sometimes it’s been caused by enthusiasts casting seeds.

This balsam has infiltrated popular culture under the names of policeman’s helmet, ornamental jewelweed, poor man’s orchid, stinky-pops, kiss-me-on-the-mountain, bee bums and Mr Noisy’s exploding plant. Yet it splits opinion.

Some – including the government – find it a nightmare weed, an alien invader with gaudy flowers and a noxious pong, a thug bullying native plants and swamping habitats. Because it is shade tolerant it dominates other plants and, being an annual, exposes stream banks to erosion when it dies back in winter. This brings out armies of volunteers, and sometimes the army, on balsam bashing operations.

Others appreciate its exotic splash of colour and scent and the nectar it provides, not only in its flowers but from glands under the leaf stalks. A vast number of insects, particularly bumblebees at the moment, feed on it when there are few other flowers about, and will do so until later in autumn when the frosts hit.

Where the climate gets warmer and wetter, plants like Himalayan balsam will thrive. Perhaps the tide of opinion is becoming more accepting of the colonists. The Himalayan balsam patch I’m watching is certainly growing rapidly and is full of life, unlike the thickets of buddleia, which are also garden escapes and have been around long enough to be prized as butterfly plants but are largely as empty as abandoned nightclubs this year. Hopefully Mr Noisy’s “outlaw” will give sanctuary to insects being wiped out in the rest of the landscape.