Summer plants for bees

The June gap

In much of northern Europe there is a genuine dip in forage in late May and June. The spring blossom — blackthorn, hawthorn, fruit, dandelion, willow — has finished. The high summer plants — lime, bramble, clover, marjoram — have not yet started. Meanwhile colonies are at or approaching peak population and consumption.

Beekeepers watch for it because colonies can go backwards or even starve in a fortnight of wet weather at this point, with supers on the hive. For gardeners it is the period worth planting for specifically, because a garden full of July flowers does nothing about it.

High summer

• Lime and basswood — a heavy flow for a fortnight in July, and audible from a distance.
• Bramble — the backbone of the British summer for bees and one of the most productive plants there is.
• White and red clover — clover in a lawn is a forage resource, not a defect.
• Marjoram, thyme, lavender and catmint — the Mediterranean herbs, which flower for months.
• Viper's bugloss — the highest nectar output per flower of almost anything temperate.
• Knapweed, teasel and thistles — the composites that carry a meadow.
• Hemp agrimony and purple loosestrife on damp ground.

The mowing question

A lawn mown weekly at 3 cm produces nothing. The same lawn mown every three or four weeks at 6-8 cm produces clover, selfheal, bird's-foot trefoil and dandelion in quantity, and studies of relaxed mowing regimes consistently find substantially more floral resource and more pollinators.

Drought and summer failure

Nectar production falls sharply in drought, because nectar is mostly water and a stressed plant does not produce it. Increasingly hot dry summers in southern Europe and Australia have made this a routine cause of failed honey crops rather than an exceptional one.

The practical response in a garden is to include deep-rooted and drought-adapted plants — viper's bugloss, calamint, russian sage, marjoram, lavender — which keep producing when shallow-rooted border plants stop.