In years with plenty of hot days during the blooming season, bumblebees, solitary bees and the few honeybees will have time to do the pollination and the farmer can get a good harvest, even without bringing in pollinating bees. The risk for the farmer is the unpredictability of the weather in temperate areas where white clover is grown for seed production. The white clover flower has evolved so that the bees can reach and collect the nectar. A honeybee can therefore visit 18-20 flowers in one minute.