Home Bee-friendly gardens: encouraging the pollinators

Bee-friendly gardens: encouraging the pollinators

Why bees are crucial to OUR survival

Bees are under threat from a variety of sources – use of pesticides, loss of habitat and the parasitic mite varroa being just three of them.

It’s not just the honeybee and bumblebee – there are also about 260 species of solitary bees in the UK, often mistaken as wasps or hoverflies.

Honey bees
Drop in honey yield worries beekeepers

In the UK, about 70 crops are dependent on or benefit from, visits from bees.

In addition, bees pollinate the flowers of many plants which become part of the feed of farm animals.

If bees go, one-third of the food we eat would not be available – no apples, onions, avocados, carrots, lemons, limes, melon, courgettes, aubergines, cucumbers, celery, cauliflower, leeks, kale or broccoli.

The economic value of honeybees and bumblebees as pollinators of commercially-grown insect-pollinated crops in the UK has been estimated at more than £200million per year.

How we can help bees and pollinators

Bees on lavender
Bees on lavender

What can we do to ease the bees’ plight?

  • Use bee-friendly plants in clumps in sunny places, not scattered about or in the shade.
  • Look for single blooms – avoid double, multi-petalled or pollen-free cultivars, as they may lack pollen and/or nectar, or it may be difficult for bees to reach them.
  • Provide nest sites for solitary bees. Some will nest in hollow stems, such as bamboo canes or herbaceous plant stems. Hole diameters in the range 2-8mm are required.
  • Cardboard nest tubes can be bought in garden centres. Holes 2-8mm diameter can be drilled in fence posts or logs. Place these nest sites in sunny positions.
  • Some solitary bees nest in bare soil or short turf. Bumblebee nest boxes can be bought but are often ignored by queens – they prefer to find their own nest sites in tunnels dug by mice or in the grass.
  • The British Beekeepers Association has an excellent guide to the state of the bee population, Asian hornet sightings and which plants to grow for pollinators – click here for more information.

Bee-friendly flowers

SPRING: hellebore, pansy, Muscari, Pulmonaria, bluebell, bugle, crab apple, daffodil, flowering cherry and currant, forget-me-not, hawthorn, pussy willow, Rhododendron, rosemary, Viburnum, thrift.

EARLY SUMMER: Aquilegia, Astilbe, Campanula, comfrey, everlasting sweet pea, fennel, foxglove, geranium, Potentilla, snapdragon, Stachys, teasel, thyme, Verbascum.

LATE SUMMER: Sedum, Salvia, Echinacea, Nepeta, Angelica, Aster, Buddleja, cardoon, cornflower, Dahlia (single), Eryngium, Fuchsia, globe thistle, heather, ivy, lavender, Penstemon, Scabious, Verbena bonariensis.

AUTUMN: Agastache (anise hyssop), wild marjoram, Echium vulgare (viper’s bugloss), Hebe elliptica, Solidago virgaurea, Valeriana officinalis.

WINTER: Bees could be foraging on any day if the temperature rises to 10C or above: Viburnum tinus, Choisya ternata, Mahonia japonica.

Using Pyrethrum – its toxicity to bees

Pyrethrum, pyrethroids and pyrethrins –  the facts:

Pyrethrum is a name for a group of natural insecticides that are extracted from chrysanthemum flowers.

The extract is called pyrethrum, and the insecticides within that extract are called pyrethrins. They are less harmful than most chemicals to humans and mammals but are still toxic to other creatures, including bees.

Pyrethrins are used in household insect sprays, outdoor and indoor herbicides, lice treatments, and flea and tick treatments. They’re often mixed with other chemicals to make them effective for longer, often pyrethroids, the synthetic version.

Insecticides labelled as containing pyrethrum and one of these other chemicals are usually more toxic than pyrethrum-based insecticides alone.

Plants poisonous to pets
Plants poisonous to pets – but catnip just makes George go nuts

Pyrethrum is classed as moderately toxic to bees and can kill them. To avoid harming them, apply pyrethrum insecticides only in the late evening, night or early morning – bees least likely to come in contact with the insecticide.

Do not apply to blooming plants on nights when dew is forecast or when temperatures are expected to be below 16C/60F. The residual effects are twice as hazardous to bees.

Liquid formulations are usually less dangerous to bees than dust or granular forms. Pyrethrum dust can be carried on the bees back to the hive, where the queen may be affected.

Pyrethrins are only mildly toxic to humans, but chemical enhancer piperonyl butoxide is considered a human carcinogen.

If you do use them, wear eye protection, long trousers, a long-sleeve shirt and a respiratory mask to decrease your exposure.

Cats and fish show a heightened sensitivity to toxicity, even in very low doses, so avoid use if you have a pond – or a cat.