Sunday, August 2, 2015

Boosting the Bumbles

After a month and a half of blooming, my Hypericum shrubs are winding down. Known commonly as St. John’s wort, Hypericum is a genus of annuals, perennials and shrubs with 31 species that are native to Georgia. I have written about this genus before, so I won’t repeat, but these plants always highlight for me the support that bumble bees need.

Bumble bees on Prenanthes
Whenever my Hypericum flowers are open, they are covered in bumble bees, especially the common but oh-so-adorable Eastern bumble bee, Bombus impatiens (named by the way, for the genus of plants Impatiens, such as our native jewelweed, I. capensis, which they like to visit). Even when the Hypericum is not flowering, these native bees come visiting to check out what is flowering. In the spring, for example, they love beardtongue flowers (Penstemon).

Bumble bee on Agastache
Bumble bees are one of the few species of native bees that are social. While they don’t make honey, they do create a cluster of wax-brood cells in small hidden spaces such as an old hole or under a clump of grass. Workers tend to the larvae in the cells, bringing more provisions as needed. Small quantities of nectar may be stored for use by the colony. This is unlike solitary bees that provision the larvae once and then do not return.

The nest is only used for one year, and the workers die over the winter. I hope one day to find a nest (even an old one). I feel sure that there is probably one somewhere on my property given how many worker bees that I see. You can see a good picture of a nest here.

There are several recent articles out lately about bumble bee population declines and the trend is disturbing. Bees are being affected by pesticide use via the movement of pesticides through the nectar and pollen that they collect. In addition, a study on insect response to climate change shows that they are less likely to move north even while their populations are diminishing in their southern ranges.

Bumble bee on Eupatorium
I have noticed what other flowers that bumble bees visit in my yard. They include anise hyssop (Agastache foeniculum), Eupatorium, rattlesnakeroot (Prenanthes) and some of the non-native herbs that I grow like oregano, catnip and basil. If you grow those herbs, let them go to flower every now and then and see what you get. Their tiny flowers are just perfect for bumbles. Holly (Ilex spp.) flowers are also so popular that I tell people not to plant hollies if they don’t like bees.

Bumble bee on Hypericum

Bumble bees are worth supporting and provide a lot of important pollination services. If you would like to support them, observe what flowers they visit already and add more or try one of the ones mentioned here.


  1. Big fat bumblebees are adorable! I have loads of them in our garden. They especially like visiting my passiflora incarnata blooms.

  2. I don't use pesticides or herbicides on my small patch of property. I consider it a home for the creatures that visit and live here.

  3. I have a nest in an old bird house. I noticed some bumbles on the outside just fanning, the opening of the bird house, with their wings. Guess they are keeping the queen cool.

  4. Love this post and bumbles! Right now they're visiting the Cup plant (Silphium perfoliatum), any of the Joe-pyes (Eutrochium) and coneflowers (Echinacea).