MOST people are aware that bees are in trouble. Due to factors including habitat loss, use of pesticides and a mysterious phenomenon called colony collapse disorder 鈥� when most of a hive鈥檚 workers just buzz off 鈥� many bee species are seeing downturns in their numbers worldwide.
There have also been declines in other pollinating insects, such as hoverflies, which, like bees, rely on sugar-rich nectar from flowering plants. The amount of nectar in England and Wales fell by about a third in the past century, mainly due to changes in farming practices, such as the growing use of weedkillers and the loss of hedgerows.
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But it isn鈥檛 all bad news. In the UK, big changes in farming had mostly petered out by the 1970s; nectar availability stopped falling and has even . On average, the UK鈥檚 towns and cities have as much nectar available for pollinating insects per square hectare as farmland and even nature reserves and parks, according to a recent .
The nectar bounty of such areas is down to home gardeners. 鈥淭he decisions you make as a gardener really do make a difference,鈥� says ecologist Nicholas Tew at the University of Bristol, UK, who led the research.
Tew鈥檚 team analysed the nectar supply from urban areas, farmland and nature reserves by gathering existing data and also by measuring nectar production from more than 3000 flowers by sucking it out in fine glass tubes.
They found that the nectar supply from urban areas was actually better than that from farms and nature reserves because it was from a more diverse range of plants: gardeners tend to stuff their flower beds with a broad range of non-native species.
This is good for insects as it helps ensure nectar is available throughout the year, and there are options that suit different species. 鈥淚f you have a lot of different plants, all pollinators will be able to find something they like,鈥� says Tew.
People who want to maximise nectar in their garden should mow the lawn less often, use fewer pesticides and avoid too many frilly 鈥渄ouble鈥� flower varieties. These showy blooms, such as some varieties of roses and dahlias, look gorgeous but lack nectar because the reproductive parts of the flower have mostly been converted into extra petals.
In 鈥渟emi-doubles鈥�, only some of the reproductive parts have been made into petals. Usually, if you can see the yellow-topped anthers in the middle of the flower, insects can reach the nectar.
Some large, exotic flowers normally pollinated by birds are too deep for insects to be able to reach the nectar. However, smart bees and wasps have been spotted stealing the nectar by cutting holes at the base of the flowers. 鈥淧ollinators are very ingenious,鈥� says Tew.
What you need
Plants, mainly with flowers that are single varieties. Avoid too many double flowers, which lack nectar
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