MASTER GARDENERS: Using pollinators to increase fruit production
For those interested in increasing the chances of a better crop of most fruits and vegetables, improving the habitat for pollinators could help improve production.
At the 2018 Upper Midwest Regional Master Gardener Volunteer Conference, University of Minnesota graduate student Nathan Hecht gave a presentation on plants that help increase production.
He talked about ongoing research that is trying to increase strawberry production in particular. Strawberries are self-pollinated to some degree, but having blooming plants nearby that provide pollen at close to the same time of the year will keep more pollinators in the area and increase production of good strawberries. More thoroughly pollinated strawberry flowers equal bigger berries and, reportedly, the berries last longer if better pollinated.
However, strawberry flowers are not the best attractor of pollinators. Pollinators tend to like larger purple or blue flowers. For this reason, it helps if there are more attractive flowers near fruit with coinciding bloom times. Additionally, simple flowers tend to have more pollen than multi-petal flowers, and are thus better attractors for pollinators.
When trying to attract more pollinators, note that there are reportedly over four hundred types of bees in Minnesota alone, and they have a variety of preferences in living habitat and pollen preferences. Having a variety of habitat and flowers is typically a good idea.
Each garden is part of a larger ecosystem, and the pollinators need the whole system to prosper as a species. Hecht liked borage flowers as companions to strawberries. The companion plantings should generally be no more than 25 to 50 feet away from strawberries or raspberries. It should be noted that pollinators in general like a fairly large variety of flowers so that they can feed whenever it is warm enough. One additional flower to consider is the sunflower, as there has been some indications that sunflower pollen helps bees get rid of some of their "gut" infections, meaning better overall bee health.
When trying to improve the habitat for pollinators, it is good to remember that close to ninety percent of native bees have their "home" in the ground, and some others in hollow stems of plants. The exact preferences for the ground are not clear, but bare spots under clump forming grasses seem to be preferred by some pollinators (not yard grasses).
Hecht also clarified that there are certain species of flies and the smaller bees that are better pollinators in cold weather than larger bees and butterflies. The hover fly and other flower flies are good for pollinating and from keeping some pests away from strawberries. Bees are the best overall pollinators, but the pollinating flies are generally considered the second best pollinators, and perform better in cool or cold weather. One of the better attractors of hover flies is a cover crop called buckwheat. With buckwheat, it is a good idea to cut off any part of the plant that contains the flowers prior to actual seed formation.
For more gardening information, visit the University of Minnesota Extension website at www.extension.umn.edu and click on "Yard and Garden." Call (218) 444-7916 and leave name, number and question and a local Master Gardener will respond as soon as possible. Or visit the Beltrami County Master Gardeners' Facebook page.