Click here to be taken to an extensive list of flowers visited by north American bees and European bumblebees. The most important thing to understand in planting flowers for bumblebees is that they need flowers throughout the season. Unlike honey bees they do not have a large store of honey in their nests, but just enough to last a few days. I have split the flowers into early, summer and late flowers, but this will vary according to where you live.
- Early flowers. When the queens emerge in the spring flowers such as spring flowering heathers, crocuses, primroses, aubrietia, comfrey, lungwort, pieris, rhododendron, bugle, cornflower, broom, poppies any flowering currants and vetches and peas are very useful. They will also gather pollen from hazels and willow catkins and early flowering fruit trees. A dense patch of heather will serve as a shelter in times when the weather changes suddenly. In my garden we let the heather flop over a low wall. The stone absorbs heat during the day and gives it out at night, so in the morning that patch is always full of slow moving queens with just enough energy to climb up the stems to drink their breakfast from the flowers. In the early days of the nest it is estimated that a Bombus terrestris queen may have to visit as many as 6000 flowers per day in order to get enough nectar to maintain the heat needed to brood her eggs. And during every foraging trip the brood will cool down, so the trips should be short. This is why it is vital that the nest is located close to rewarding flowers.
- Summer flowers. In general most cottage garden type of flowers are useful to bumblebees such as Indian balsam, Phacalia, viper’s bugloss, geraniums, aquilegia, lupins, campanulas, as well as brambles, raspberry, strawberry and other soft fruits, and many herbs such as the different varieties of thyme, marjoram, sage, and borage. Old-fashioned roses provide a good source of pollen, you can hear them gathering pollen from some flowers as they sonicate the anthers to dislodge the pollen. This is a higher sounding buzz than usual. Many flowers especially bred for showy displays do not have nectar, for example some nasturtiums are nectar-free, normally these provide a large amount of nectar per flower and so are very useful. And double-flowered varieties may or may not produce nectar, but the extra petals often make it too difficult to reach. Foxgloves are used by the longer tongued bees not only for nectar but also as a place to shelter during sudden showers, but some of the more showy ones have flowers that do not open properly.
- Late flowers. Lavenders and salvias are useful later in the year, actually most of the herbs used by cooks are used by bumblebees. Honeysuckle is also very valuable as it provides a rich supply of nectar.