Buddleia

Value to bees

Nectar

High

Pollen

Low

As a honey crop

Not a honey source

Which bees, and why

Butterflies and day-flying moths are the primary visitors and the flower is built for them — a narrow tube suited to a long proboscis. Honey bees and bumblebees use it but work it less efficiently, and many bees cannot reach the nectar at all.

A long narrow corolla tube designed for lepidopteran mouthparts. Short-tongued bees are largely excluded, which is why the bee ratings sit well below the butterfly reputation.

Worth knowing

The separate ratings do real work here. Buddleia offers substantial nectar and very little accessible pollen, so it feeds adult insects and contributes almost nothing to raising the next generation of bees. A garden of nothing but buddleia would starve its own pollinators.

Flowering

In flower

July to September (northern hemisphere)

Deadheading spent panicles reliably extends flowering into October and simultaneously reduces the seed set that makes it invasive — the two goals point the same way.

When nectar flows

Copious, sugar-rich nectar held in a narrow tube, produced steadily through the day. It performs well in heat and drought.

Year-to-year variation

Dependable every year. Not a honey crop.

Growing it

Conditions

Full sun, any drained soil including rubble and masonry. It grows out of walls and railway ballast unaided.

Size

2-4 m, and considerably more if never pruned.

Native range

Central China and Japan.

Suits

Large gardens, Small gardens, Walls and fences

• Prune hard to a low framework in early spring. Buddleia flowers on new wood, and an unpruned plant becomes a leggy shrub flowering out of reach.
• Deadhead through the season. It extends the flowering and stops the seed dispersing, and each panicle can carry tens of thousands of seeds.
• Do not treat it as a complete pollinator planting. It needs pairing with genuine pollen sources — marjoram, phacelia, single-flowered daisies — or it feeds adults while starving brood.

What it looks like

A fast-growing arching shrub with grey-green lance-shaped leaves and long dense conical panicles of small tubular flowers in purple, white, pink or yellow, each with an orange eye.