Master gardeners weigh in on decline of native pollinators

Chisago County master gardeners Tom Dickhudt and Leslie Scharafanow said native pollinators, like these bees in Scharafanow’s garden, are integral to growing healthy plants.

Chisago County master gardeners Tom Dickhudt and Leslie Scharafanow said native pollinators, like these bees in Scharafanow’s garden, are integral to growing healthy plants.

Just about anyone who owns plants that flower knows the importance of bees and other native pollinators.

They flit from flower to flower in search of nectar, pollinating as they go, which helps in the propagation of healthy plants.

Without native pollinators, numerous plants — some of which are food sources for much of America — would struggle to survive; yields would go down.

This scenario might seem abstract, but it’s not that far from reality.

The insects that are integral to pollination are declining, and part of the reason for this decline is due to human activity.

Tom Dickhudt, a Chisago County master gardener, said some of the main culprits in the decline of native pollinators are neonicotinoids, which are pesticides.

He described neonicotinoids as “systemic,” meaning that when they’re used, they actually end up being within the plant, as opposed to pesticides that are sprayed and stay on the outside of plants.

Systemic pesticides are effective in combating insects that damage a myriad of plants, but the scientific community, Dickhudt said, is finding out that there are far-reaching negative repercussions to using neonicotinoids.

“This fad started when people were talking about the emerald ash borer and using pesticides within the ash trees, which is systemic, and then people started asking if this stuff is used other places,” Dickhudt said, adding that neonicotinoids have been around for quite some time. “They found out it was used everywhere.”

Native pollinator decline due to the use of neonicotinoids, which are systemic pesticides, is gaining more attention nationwide. Photos by Leslie Scharafanow

Native pollinator decline due to the use of neonicotinoids, which are systemic pesticides, is gaining more attention nationwide. Photos by Leslie Scharafanow

Leslie Scharafanow, also a Chisago County master gardener, said neonicotinoids, which can be found in several shrub and insect control products available at big box stores and garden centers, effect the central nervous systems of insects that come into contact with the plants treated with the chemicals.

“The focus (of the research) has really been on native bees and honeybees,” Scharafanow said. “The neonicotinoids impact their ability to fly, navigate and forage for food.”

Dickhudt and Scharafanow said neonicotinoids are one of the contributing reasons for bee colony collapse, along with other factors, which include loss of habit, viruses and parasites.

“Pile neonicotinoids on top of those other issues, and the bees are taking a big hit,” Scharafanow said.

Alternatives to systemic pesticides

Dickhudt and Scharafanow are both proponents of having native plants in home gardens, which, they say, don’t seem to attract as many destructive bugs.

“I grow a lot of native plants, and I have a big prairie,” Scharafanow said. “The pesky bugs aren’t really interested in the native plants. They’re interested in my fancy (non-native) plants.”

Scharafanow noted that even though the bugs do tend to eat portions of her non-native plants, those plants usually tend to survive.

“Sometimes it’s just best to leave them alone,” she said.

If gardeners do want to use pesticides, Dickhudt and Scharafanow stressed they should read the labels on the products, and don’t simply employ the “point and shoot” method when it comes to application.

Dickhudt said a complete ban of neonicotinoids probably wouldn’t happen anytime soon because it’s really the only effective systemic pesticide used in the nursery industry.

“I get the professional nursery magazine, and basically the professional nurseries are saying neonicotinoids are terrible things, but they have no substitute and will use them until there is one.”

Scharafanow mentioned one more way to help area native pollinators: Create neighborhood habitats for them.

“Because of urban sprawl, bees just don’t have the wide-open prairies like they used to,” she said. “I think it would be nice if neighbors got together and planted bee-friendly gardens,” she said, noting that it’s important to have a variety of plants, which ensures some will be flowering in the spring, summer and fall. “That way, the bees don’t have to forage; they’ll have this nice area where they can get everything they need, rather than having to fly from one block to another.”

For more information on bees, pollination and how to create native-pollinator-friendly habitats, visit http://beelab.umn.edu.

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