Oliver Pemberton
Why Pollinators Earn Their Keep on the Plot
If you grow courgettes, runner beans, apples, strawberries or broad beans, you are already relying on insects. Every third mouthful of food we eat depends on pollination, and on an allotment that ratio feels even higher. Bees and butterflies do the heavy lifting free of charge, and the return on a few packets of seed is remarkable.
Bumblebees are the specialists worth courting. They work in cooler, duller weather than honeybees and they can buzz-pollinate tomatoes and aubergines, shaking the pollen loose in a way no amount of tapping the cane will match. Butterflies are less efficient pollinators but they are wonderful indicators of a healthy plot, and their caterpillars feed the birds that then help keep aphids in check. A plot humming with insects is usually a plot with fewer pests and better fruit set.
Choose Flowers That Actually Fill the Larder
Not all flowers are equal. Plant breeders have spent decades producing double blooms that look magnificent but offer little or no nectar, because the extra petals have replaced the bits that make it. Stick to single, open, daisy-like flowers where the centre is visible, and you cannot go far wrong.
Reliable nectar-rich choices for a UK plot include:
- Borage – a magnet for bumblebees, self-seeds freely, and the young leaves taste of cucumber.
- Phacelia – a green manure that doubles as a bee banquet; sow in spring and dig in before it sets seed.
- Calendula and nasturtium – cheerful, edible, and happy in a spare corner or between brassicas.
- Lavender, oregano, marjoram and thyme – herbs that earn their keep twice over in the kitchen.
- Cosmos, scabious, echinacea and helenium – late-summer workhorses that keep going into autumn.
- Poached egg plant (Limnanthes douglasii) – low-growing, self-seeding, and loved by hoverflies as well as bees.
Plant in generous drifts rather than single specimens. Insects find a block of colour far more easily than a lonely plant dotted about, and a square metre of borage will support more bees than twenty scattered plants.
Keep the Larder Open From March to November
The common mistake is a glorious flush in July and nothing either side of it. Queen bumblebees emerging in early spring are desperate for food, and the bees still flying in October need fuel to see them through winter.
For the hungry gap, think pulmonaria, crocus, willow, flowering currant and comfrey. Comfrey is especially valuable – a single clump can be cut for mulch and will flower again, and the bees adore it. For autumn, leave sedum, asters, ivy and single dahlias to do the work. Ivy is one of the most important late nectar sources in the British countryside, so resist the urge to hack it all back in September.
Sow a few hardy annuals in late summer for an early flush the following year, and let a few herbs run to flower instead of pinching them all out. A parsley or coriander left to bolt will bring in a surprising number of insects.
Provide Shelter, Nesting Sites and a Drink
Nectar is only half the story. Bees need somewhere to live and butterflies need somewhere to hide from wind and rain.
- Leave a patch of long grass undisturbed over winter – bumblebee queens and many caterpillars overwinter in tussocks.
- Build a log pile in a shady corner. Dead wood, hollow stems and loose bark are prime solitary bee real estate.
- Grow a mixed hedge or leave a boundary untrimmed – hawthorn, blackthorn and holly provide both blossom and shelter.
- Plant caterpillar food plants: nettles for peacock, small tortoiseshell and red admiral; garlic mustard and honesty for orange tip; buckthorn for brimstone.
- Set out a shallow dish of water with pebbles or gravel for landing. Butterflies will take minerals from damp soil, so a small puddle left to itself is worth having.
Aim for a sunny, sheltered spot facing south or west. Bees are cold-blooded and need warmth before they can fly, so a border against a fence that catches the morning sun will be far busier than the same plants in a shaded corner.
Avoid the Things That Undo the Good Work
The quickest way to lose your pollinators is to spray. Even organic-approved pesticides can harm bees, so rely on barriers, companion planting and a healthy population of predators instead. If you must treat, do it in the evening when flowers are closed and bees have gone home, and never on a plant in flower.
Also resist the temptation to be too tidy. Cutting back everything in October removes seedheads, hollow stems and hibernation sites in one afternoon. Leave the herbaceous perennials standing until late spring, when the new growth starts to push through, and you will have helped a whole generation of insects through the worst of the weather.
Simple First Steps for a Busy Plot
If time is short, start with three things. Sow a strip of phacelia or borage along one edge of the plot and let it flower. Put a shallow water dish near the shed. Then leave one corner rough and uncut over winter. That is perhaps half an hour of work, and it will transform the number of bees and butterflies visiting your plot – and quite possibly the size of your bean crop too.
