Why should we care about bees?
Bees provide significant benefits to us, including pollination of our fruit and vegetable plants. Honeybees make honey that is a delicacy in any kitchen. Introduced honeybees are responsible for pollinating over $10 billion worth of U.S. food crops each year. Wisconsin has over 400 species of native bees that also are responsible for pollination of many plants. Unlike honeybees, the majority of native bees do not live in colonies. Instead, most of them construct solitary nests below ground in burrows or above ground in cavities. Unfortunately, both native and introduced honeybees are facing significant declines in their population due to loss of habitat, climate change, diseases and mites, excessive pesticide use or misuse and pollution.
We need to take steps in our communities to help bees and other pollinators’ populations thrive in our urban environments. Plant a wide variety of trees, shrubs, perennials and annuals with overlapping and sequential blooming periods throughout the season. Flowers that bees are attracted to include bright white, yellow, blue and purple with a fresh, mild to sweet fragrance. Bees like tubular to shallow flowers or flowers with landing platforms. Flowers that produce nectar or have slightly scented, sticky pollen attract bees. In particular, trees can provide a good source of pollen early in spring right when bees are laying their eggs and the resulting larvae use it for their development. Throughout the rest of the growing season, adult bees use nectar from flowers as a carbohydrate source to continue their reproduction and pollination of plants. Besides a continuous food source, bees also require water, adequate nesting habitat and an adequate amount of sunny, open space.
When bees are pollinating flowers, reduce or avoid the use of pesticides, especially broad-spectrum insecticides. Even organic pesticides can be highly toxic to bees and other pollinators. Avoid spraying trees during bloom time, especially when lindens and fruit trees are in bloom as these trees are some of their favorite choice for food. Following is a list of tree species that are known for their source of either pollen or nectar that are critical to sustaining bees.
Early Spring
Acer spp.: maples, especially red maple Amelanchier spp.: serviceberries Cercis canadensis: eastern redbud Cornus mas: corneliancherry dogwood Corylus spp.: hazelnuts, filberts Prunus spp.: cherries, plums, peaches, apricots, nectarines (some bloom mid-spring) Populus spp.: poplars Salix spp.: willows Sassafras albidum: sassafras
Mid-Spring
Aesculus spp.: buckeyes and horsechestnuts Gleditsia triacanthos f. inermis: thornless honeylocust Halesia tetraptera: Carolina silverbell Liquidambar styraciflua: American sweet-gum Malus spp.: apples and crabapples Nyssa sylvatica: black gum, tupelo, sour gum, the food source of tupelo honey Pyrus spp.: pears
Late Spring
Castanea spp.: chestnuts Cladrastis kentukea: American yellowwood Crataegus spp.: hawthorns Liriodendron tulipifera: tulip-tree, yellowpoplar, the food source of tulip-tree honey Ptelea trifoliata: wafer-ash, hop-tree Robinia pseudoacacia: black locust (invasive, on DNR NR-40 list), the food source of locust honey Sorbus spp.: mountainashes Tilia spp.: lindens and basswood, American basswood is the food source of basswood honey
Early Summer
Catalpa speciosa: northern catalpa Cornus alternifolia: pagoda dogwood Rhus spp.: sumacs Syringa pekinensis: Peking lilac Syringa reticulata: Japanese tree lilac
Mid-Summer
Koelreuteria paniculata: golden raintree Oxydendrum arboreum: sourwood, sorreltree, the food source of sour – wood honey Styphnolobium japonicum: Japanese pagoda-tree (formerly Sophora japonica)
Early to Mid-Fall
Heptacodium miconioides: seven-son flower, good late-season food source for pollinators
– Dr. Laura G. Jull, Dept. of Horticulture, UW–Madison