Himalayan balsam

Value to bees

Nectar

Very high

Pollen

Very high

As a honey crop

Major honey crop — yields a surplus in good years

Which bees, and why

Worked intensively by bumblebees and honey bees, which emerge from the hooded flowers dusted white with pollen — the most recognisable sight in late-summer riverside beekeeping. There is evidence that its abundance draws pollinators away from native plants nearby, reducing their seed set, so even the forage benefit is not unambiguous.

Worth knowing

Outstanding on both counts, at a time of year when little else offers anything. This is the whole difficulty.

Flowering

In flower

July to October (northern hemisphere)

A long late season, continuing until the first frosts.

When nectar flows

Exceptional. It is among the highest nectar-producing plants recorded in Europe, and in a stand of any size the flow is heavy enough to yield a surplus.

Year-to-year variation

Reliable where the plant is abundant, which is increasingly everywhere along British and European rivers. Some beekeepers value it highly; the honey is pale and mild and bees working it emerge dusted white with pollen.

Growing it

Conditions

Damp ground in sun or part shade, particularly riverbanks and wet woodland. It needs no encouragement at all.

Size

1-2.5 m tall, and the tallest annual in Britain.

Native range

The western Himalaya. Introduced to Britain as a garden ornamental in 1839 and now naturalised along watercourses across Europe, North America and New Zealand.

Suits

Farm scale

What it looks like

A tall, hollow-stemmed annual with reddish stems, lance-shaped toothed leaves, and hooded pink to purple flowers shaped like a helmet. The ripe seed capsules explode at a touch, throwing seed several metres.