Posted by: Bystander PJ19 SEP 2012
When I wrote about an attempt to control invasive Himalayan balsam in a local nature reserve (PJ 2012;288:797), I was criticised by a PJ letter-writer on the ground that the flowers are a nectar source for honey bees at a time when many other plants have stopped flowering (PJ 2012; 289:52). Personally I would rather help the bees by encouraging late-flowering native plants. In any case, I rarely saw honey bees among the insects that visited the alien balsam.
But a shortage of nectar in late summer is certainly a problem for bees. In early summer, rural bees can find a plentiful supply in the yellow fields of oilseed rape that cover much of Britain. But then they may be starved of nectar for weeks until a new crop comes into bloom. Intensive farming has destroyed many of the wild plants they may once have visited.
So when bees can no longer go to town on oilseed rape, what can they do? They can go to town. Urban parks, gardens and allotments provide a rich source of nectar for most of the year, so that towns and cities do not suffer big fluctuations in nectar flow. Urban bees also escape the effects of farm pesticides.
Central London has hundreds of beekeepers and thousands of hives, including some on the roofs of famous buildings. Metropolitan bees benefit from the milder weather experienced in city centres, which means that the beekeeping season is longer than in rural areas and usually more productive. London hives can provide up to three times as much honey as rural hives.
The wide choice of source plants means that London honeys vary in flavour. But at least they do not smell of cabbage like honey made from oilseed rape nectar. And London beekeepers regularly win taste and quality awards for their honey.