Rosebay willowherb

Value to bees

Nectar

Very high

Pollen

High

As a honey crop

Major honey crop — yields a surplus in good years

Which bees, and why

Worked heavily by honey bees and bumblebees together, and in the far north largely by bumblebees, which fly in cooler conditions. The long spike lets a bee work upward through dozens of flowers without flying, which is an efficient forage shape.

Open flowers with a short nectar tube, accessible to short-tongued and long-tongued bees alike.

Worth knowing

A major nectar source at a point in the year when many landscapes have gone quiet, and the mainstay of high-summer beekeeping across boreal North America and Scandinavia.

Flowering

In flower

June to September (northern hemisphere)

Peaks in July and August. The spike opens from the bottom upwards over several weeks, which stretches what would otherwise be a brief flow into a long one.

When nectar flows

Generous and reliable in warm weather, and unusually so for a high-summer plant at northern latitudes. Each flower is protandrous — male phase first, then female — which spreads the reward across the spike.

Year-to-year variation

Depends on disturbance more than on weather. A stand that yielded heavily for a decade simply stops as scrub and trees close over it, so production migrates with logging and fire.

What it does to the honey

Willowherb nectar yields a near-colourless honey with a buttery, faintly tea-like delicacy. It is among the palest honeys produced anywhere, and the paleness is genuinely the plant rather than any processing.

Growing it

Conditions

Sun to light shade, most soils, and above all disturbed or recently cleared ground.

Size

1-2.5 m.

Native range

Circumboreal — northern Europe, northern Asia and North America, on disturbed ground throughout.

Suits

Meadow or wildflower area, Large gardens

• Vigorous to the point of thuggishness in a border — it spreads by rhizome as well as by seed and is difficult to remove once established.
• Best in a wild corner, a meadow or a large garden where it can be left alone. In a small bed it will win.
• A useful plant for anyone rewilding disturbed ground, where its aggression is the feature rather than the problem.

What it looks like

A tall unbranched perennial with narrow willow-like leaves spiralling up the stem, topped by a long spike of four-petalled magenta-pink flowers opening from the bottom upwards, followed by masses of fluffy wind-borne seed.