Pollinators and pesticides

Cathy Wood

A honeybee at work on a wild geranium. Photo by Jim Lundstrom.

A garden buzzing with bees and other pollinators is a sign of a healthy ecosystem. Create a pollinator-friendly yard by providing safe space with flowering plants throughout the growing season, places to nest and pesticide-free wildlife habitat.

Provide a small water feature, possibly a hanging bird bath and another on the ground.
Leave the leaves or rake them into your garden, under trees and bushes to enrich the soil and keep the caterpillars safe.  Cut stems of spent flower stalks provide for over-wintering larva.

Plant native trees and shrubs that bloom for the pollinators and provide berries/nuts for the wildlife.
Add ground cover under trees to provide “soft landings” for caterpillars.

How to begin a pollinator garden 

Start small, then expand over time – maybe in the boulevard, along the alley or a fence.
Be aware of site conditions, soil type, moisture, sun, space.

Remove the sod or vegetation by hand, or by sheet mulching which takes a few months.

Consider design layout, paths, appearance.

Buy seed or plants from organic growers, especially avoid plants treated with neonictinoids.

Choose native plants and plants specific to this region. 

Select a variety of mostly native plants, for blooms from  April – October.

Consider height and shape, year-round interest, colors.

Set plants 12 inches apart or less, depending on size, in a hole deep enough to hold the entire root system up to the original soil level. Plant masses of flowers.

Keep taller plants near the back.

Create a border with mulch, edging, stones or ground cover.

Plant slopes and hillsides with trees, shrubs, grasses and flowers for pollinators, to reduce erosion and eliminate mowing.

Maintenance

Continue weeding. Water plants regularly the first season, if no rain.  

Native plants are slow to grow the first year, expanding their root system. By year three, the plants will be flourishing.

Consider a bee-lawn

Traditional lawn offers little support for pollinators. Shrink your lawn or incorporate low-growing flowering plants by re-seeding with pollinator-friendly lawn mixes. Bee-lawns reduce mowing, fertilizer and watering. Set your mower 3 inches or higher to encourage blooming.

Native plants and bee-lawns don’t need fertilizer. Most of the fertilizers sprayed or sprinkled on our lawns gets washed away. They end up in our streams and lakes causing problems like algae blooms.

What to do about garden pests?

A few holes in your plants can be a good sign, that your garden is providing food for caterpillars.
Identify which pest you may be dealing with, the underlying cause, then research how to manage it.

Try hand-picking the pests or spray them with water, and prune the damaged plant parts.  

When necessary, replace the plant with one better suited to the location.

Pesticides

Bee and butterfly populations are decreasing due to drought, severe storms and pesticides.
Sources include agriculture, stormwater runoff and commercial and residential properties.

Insecticides kill insects (pollinators). Herbicides kill flowering plants, which reduce nectar or pollen sources for pollinators. Fungicides weaken pollinators impacting survival and population size. Some pesticides can remain in the environment for days, weeks, or longer,

Even low-impact pesticides such as insecticidal soap and horticultural oils should be used with caution. 

Pesticide use guidelines

Use pesticides only when a pest is seriously damaging a plant.

Again, identify which pest you are dealing with.

Choose a targeted, reduced risk product. Avoid multiple use products.

Avoid applications during bloom time.

Never apply pesticide when pollinators are present.

Using a landscape/lawn service? Ask which products they use for managing weeds.

What to do about weeds?

A weed is an undesirable plant in a place we don’t want it.

When you plant a new garden, you will have weeds for a year or two. 

Pull or use tools before weeds go to seed.

Choose organic untreated mulch such as wood chips (on- to two-inch layer).

Use sheet mulching or solarization for large areas to smother weeds.

Tolerate some native weeds, but invasive weeds should be removed.

Top invasive non-native plants in Duluth include common/European and glossy buckthorn, Japanese and Bohemian knotweed, common tansy, garlic mustard and wild parsnip. 

Caution: wild parsnip sap may cause phytochemical burns! Wear gloves, rinse skin with soap and water.

Other invasive plants include Japanese barberry, knapweed, oriental bittersweet, non-native bush honeysuckle and bull thistle.

Learn to identify invasive plants:

Midwest Invasive Plant Network

MN Department of Agriculture

Buckthorn is accepted at the Western Lake Superior Sanitary District (WLSSD) MRC and Yard Waste site.  For other invasive species disposal questions, call 218-722-3336. Do not compost!

Avoid using herbicides such as glypho-sate (sold as Roundup) for control. There is research data showing increased risk of cancer in humans and animals with repeated use of Roundup. Rainfall washes these chemicals into storm sewers and then they flow directly into Lake Superior. WLSSD does not treat stormwater before it is returned to Lake Superior.

Also note that washing cars on impervious surfaces such as a driveway is not advisable. Again, these washing solutions are flushed into the storm sewers to end up in the lake without any “decontamination” treatments.

Deer problems?

Realize that no plant is deer proof, and may require protection such as fencing. Repellents, either purchased or home recipes, are short lived remedies. They need to be applied weekly or more often during rainy periods. Follow the pesticide use guidelines above.

Success of any plants in the landscape will depend on local deer populations and weather conditions. Deer resistant native plants include hyssop, milkweeds, coneflowers, goldenrods, sunflowers, pearly everlasting, yarrow and pussytoes. Check your local native plant nursery for other options.

Vegetable gardens

Pollinators play an essential role in food production, also providing forage sites for them.
Choose plant varieties resistant to common pests and diseases.

Decrease pest problems by companion planting and crop rotation. 

Need more support? 

Attend local Arrowhead Chapter – Wild Ones events to learn more about landscaping with native plants. Check their website for local native plant nurseries.  

Make your garden a monarch waystation by adding milkweed.  There are over one hundred monarch waystations in the Duluth area. Check Monarch Watch to certify your garden.

Grant available

Minnesota Lawns to Legumes program provides funds to help establish pollinator habitat to support the rusty patched bumble bee and other pollinators. It offers a combination of workshops, coaching, planting guides and cost-share funding ($400 grants) for installing pollinator-friendly native plantings in residential lawns. 

The application deadline for the Spring 2025 Lawns to Legumes grant is November 30, 2024. Recipients will be notified in mid-January 2025. 

Pollinators and people need healthy landscapes. Join the effort to increase native plant and wildlife biodiversity in your neighborhood.

Cathy Wood is president of both the Arrowhead Chapter of Wild Ones and Duluth Monarch Buddies. She is a lifelong gardener, first with traditional perennials in southern Wisconsin, transitioning to native plants for Duluth’s many challenges. Cathy lives on a half-acre city lot, certified as a monarch waystation, pollinator and wildlife habitat.