From the Ground Up: Planting for pollinators: Shrubs, trees good for bees

When planting for pollinators, it's important to choose pollinator friendly shrubs and trees, which provide a long-term balanced habitat. Shrubs and trees, or 'woody stock' are the backbone plants for an ecosystem, which includes all the elements needed for a supportive environment. Habitats should be multitiered, allowing for all sizes and types of pollinators to thrive.

Trees and shrubs provide nesting opportunities for bees and butterflies.

Bees can make their nests in abandoned rodent holes found at the base of a shrub, or in hollows, crevices or holes within the bark of a tree trunk. I have enjoyed seeing the roosting of monarchs over night in the river birch located at Noelridge Park. Dead trees (snags) and branches are the preferred nesting spot for small to large species of bees and beetles, so various heights are recommended.

Trees and shrubs provide excellent foraging potential.

A decent sized shrub may be densely covered in nectar and pollen-rich flowers. This means foraging is efficient, requiring less energy for the bees to fly about in search of further sources of food. In particular, spring blooming trees and shrubs are essential to provide food for the emerging native pollinators. Cherry, apple, crabapple and magnolia are a few of the trees and forsythia, lilac, rhododendron and blueberry are top shrubs.

Even the hollow stems of shrubs can be useful to bees.

Tiny solitary bees may hibernate or make nests in them. For example, the tiny harebell carpenter bee is only about 6 mm or 7 mm in size and can easily be mistaken for a little black fly. It may create its nests in hollow stems of plants.

Trees and shrubs can provide a much needed windbreak for foraging bees and other pollinators.

Honeybees, for example, can withstand only 25 mph winds, and while monarchs use the wind currents during the migration to and from Mexico, normally they can forage only in light wind. When choosing, be sure to plant a variety of both deciduous and conifer trees and shrubs. A few favorites are honeysuckle, redbud, dogwood, willow and serviceberry. Although conifers do not require pollination, they can provide dense protection from the elements — rain and wind.

With summer beginning, it's a great time to add a few pollinator favorite shrubs and/or trees to your landscape. Take some time to investigate different species, and where they might fit into your landscape. The 'Trees Forever Pollinator Primer' is an excellent resource to use as a guide. The 'Working Trees for Pollinators' is also available online. With some advance notice, most local nurseries will be glad to order the exact tree/shrub that you would like, so you can introduce both familiar and unique pollinator trees to your neighborhood.

For gardening questions, call the Linn County Extension Master Gardener Hortline at (319) 447-0647.