Some tips on how to attract bees.
Research suggests that flower groupings (clumps) of at least 3 feet (1 m) in diameter of an individual species are more attractive to pollinators than species that are widely and randomly dispersed in smaller clumps. Large clumps of individual species are easier for flying pollinators to find in the landscape, especially in the case of small urban habitats or small pollinators with flight ranges as short as 500 feet (152 m). For a natural look, these clumps can be distributed at random in a landscape, rather than in regularly spaced straight lines. In a large area of habitat, planting clumps may be impractical and not necessarily important so long as flowering plants are abundant.
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Flight Range
The flight range of native pollinators is a necessary consideration for restoration and management of pollinator habitat. The distance a pollinator can fly varies among species, and thus the distance between food and nesting sources must be carefully considered. This may be most important for bees because unlike butterflies, flies, and beetles they transport pollen and nectar to a nest and therefore are locked into visiting the flowers surrounding their nest. Other pollinators may forage much more widely, roaming across the landscape in search of food or egg-laying sites, sometimes over many miles even hundreds of miles, as in the case of monarch butterflies.
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The distance a bee can fly between nest site and forage area is related to its size. Small species may fly no more than 500 feet (152 m) while larger species such as bumble bees may fly more than a mile (1.6 kilometers). A general rule of thumb in habitat design is to have flowers no more than a few hundred feet (100 m) from potential nesting areas. With bumble bees, however, blueberry and cranberry farmers sometimes seek to establish habitat some distance from the field. When learning how to attract bees and support their populations in more heavily managed farm landscapes, you should work to have a patchwork of blooming plants, including flowering crops and wild plants on field margins or in-field insectary plantings, separated by no more than 500 feet (152 m).
More at
http://www.motherearthnews.com/organic-gardening/how-to-attract-bees-zebz1305zstp.aspx?newsletter=1&utm_content=06.28.13+GFSS&utm_campaign=2013+GFSS&utm_source=iPost&utm_medium=email
This is useful stuff. I enjoy it.