What do apples, strawberries, cucumbers, different types of squash, pumpkins, watermelons, and almonds all have in common?
Pollinators are needed to produce these crops, as well as many others. Within our landscapes, conserving a variety of bees is possible by planting landscape attractive, bee-friendly trees and shrubs.
In a scientific study conducted by Dr. Daniel Potter, University of Kentucky Entomologist, and a graduate student, Bernadette M. Mach, they counted the number of visits made by bees to flowers of trees and shrubs.
They also identified the different types of bees including native bees such as the mason bee and non-native bees. As a result, various trees and shrubs were identified that bloom throughout the year to serve as food sources.
One of the earliest blooming large shrubs visited by bees is the Cornelian cherry (Cornus mas), which blooms in March. It is covered in three-quarter-inch clusters of flowers.
Each flower is surrounded by tiny yellow bracts, which are modified leaves. In full bloom, even though the bracts are small, the tree stands out in the landscape with the yellow color.
The large shrub to small tree reaches 15 to 25 feet tall with a spread of 15 to 20 feet. Bright red fruits are produced in the summer. The grayish-brown bark exfoliates on the older branches providing another interesting characteristic to the landscape.
Cornelian cherry prefers to grow in good, well-drained soil and can grow in partial shade to full sun.
Redbud (Cercis canadensis) is a native, bee-friendly tree, which blooms around April.
Half-inch long, reddish-purple flowers are produced on the branches before the leaves appear. Flowers are often found on the trunk too. As an added feature, attractive, brown, flat seed pods often stay on the tree until the following spring.
Redbud grows well in sun or shade and is best used as an understory tree. The soil should be well drained. Verticillium wilt and borers are sometimes a problem with redbuds, especially on sites with a lot of stress factors.
Flowering crabapple (Malus hybrids) trees bloom in the spring. They range in height from 10 to 30 feet depending on the many cultivars available. The flower color is white or pink to rosy red.
Clusters of flowers cover the tree when in full bloom. An added interest is the fruit which turns yellow to red in color and varies in size from 0.375 to 2 inches.
Some trees have attractive, small, persistent fruit while others have larger fruit that falls early and creates litter. It is best to plant crabapples away from sidewalks and driveways to avoid walking on the fruits.
Disease resistance is an important consideration when selecting a crabapple cultivar. Many cultivars are very susceptible to apple scab, fire blight, cedar apple rust, and powdery mildew. Apple scab causes the leaves to fall off the tree early in the season.
Fire blight can quickly kill a crabapple tree if it does not have resistance to this disease Information about disease resistant cultivars studied at the University of Kentucky is available in “The Flowering Crabapple” publication at the website http://www.ca.uky.edu/agc/pubs/id/id68/id68.pdf or from your county Cooperative Extension Service office.
Common winterberry, Ilex verticillata, is a deciduous holly and blooms during June. The flowers are small with white petals and appear in groups. An added bonus is the many bright red fruits that persist into winter.
Male flowers and female flowers are produced on different plants so the holly depends on pollinators. In order to have berries, you will need one male plant among several female plants.
The slow to medium growing shrub reaches 6 to 8 feet in height and width. The plant has a good fall leaf color as well. This holly tolerates wet conditions and prefers acidic soil. It grows in full sun and partial shade.
Summersweet clethra (Clethra alnifolia) is a shrub that blooms in June and July. White flowers are attached up and down 2- to 6-inch long stems. Individual flowers are .33 inch wide.
The flowers open first at the bottom of where the blossoms begin to the tip of the stem resulting in a long blooming period. The flowers are fragrant. The height of the shrub ranges from 3 to 8 feet tall and spreads 4 to 6 feet wide. If it is growing in conditions the plant prefers, it will grow bigger. Clethra prefers moist to wet soil and thrives in partial shade to full sun.
Glossy abelia (Abelia xgrandiflora) blooms during the summer months of July through August and possibly into September. The flowers are shaped like a funnel and described as white with a hint of pink. Flowers appear on new growth. The plant forms a mounding habit.
It can grow 3 to 6 feet tall and wide. Abelia prefers acidic soil that is well drained.
For more information about bee-friendly trees and shrubs, contact the Daviess CountyCooperative Extension Service at 270-685-8480 or firstname.lastname@example.org.
Annette’s TipJoin in conserving bees in your landscape and check out the list of “Woody Ornamentals for Bee-Friendly Landscapes (Ohio Valley Region)” available online at https://entomology.ca.uky.edu/files/bee_friendly_shrubs_and_trees_handout.pdf or through your County Cooperative Extension Service Office. Plants on the list have desirable landscape characteristics as well for your garden. If you do not want bees close to the house or spaces used often in the landscape, then consider planting them in the part of the landscape where you do not frequently visit or work.
Annette Meyer Heisdorffer, PhD, is the horticulture extension agent with the Daviess County Extension Office. She can be reached by calling 270-685-8480.