Bees need trees, not ‘No Mow May’

Pussy willow (Salix discolor) catkins emerging in March or April in Ottawa. Soon the male catkins will be covered in yellow pollen, providing one of the first pollen sources for bees. Photo: Dave Keys

Photo: Christina Keys

 By Christina Keys


Over the past couple of years, you’ve probably heard of the No Mow May challenge.

The concept behind No Mow May is to delay mowing your lawn until June to allow insects to forage on wildflowers that grow in the lawn during spring. This movement was popularized in Britain, and in the last few years has arrived here.

However, the movement is misguided in the Canadian context, particularly in urban areas like the Glebe.

The purpose of No Mow May is to support pollinators early in the season as they emerge from hibernation. In Britain, there are commonly native flowers that sprout up from unmown turf to support bees and other pollinators that have co-evolved with those flowers.

In Ottawa, we do not often have native flowers thrive among our non-native turf grasses. Instead, we have non-native or invasive species such as dandelions, Siberian squill, crabgrass, creeping charlie and black medic which are not suited to our native bees. Neglecting to weed invasive species from your lawn is also harmful to local ecosystems.


Bees need trees

Tree pollen is the earliest food source for Ottawa’s native bees. In particular, wild bees thrive on native willows, maples, serviceberries, wild cherries and dogwoods. When our yards lack this pollen, generalist native bees turn to dandelion pollen, but it is too low in the quality proteins they need. Specialist bees cannot feed on dandelions, as they feed exclusively on the pollen of the particular native plant species that they evolved with over thousands of years.

Wildlife-friendly garden design includes early flowering trees and shrubs and also plans for continuous blooms from spring into November. Spring flowers include wild columbine, woodland strawberry, golden Alexander and hairy beardtongue. Late flowering species are smooth aster, grey goldenrod, tall ironweed, spotted Joe Pye weed and cardinal flower.


Less lawn is more

The actions we need to take to support native bees and other pollinators are more complex than delaying mowing.

Instead of No Mow May, reduce the amount of yard that even needs mowing by expanding your garden beds. Lift the turf or smother it with cardboard and mulch. Establish a drought tolerant garden planted densely with native perennials, sedges and grasses. Add flowering trees and shrubs as space allows.

If you prefer the lawn look, plant dozens of Pennsylvania sedge in sunny conditions or ivory sedge in shade.

Support pollinators by minimizing spring and fall clean up in your yard to allow habitat for hibernating insects, amphibians and other creatures. Never rake garden beds. Remove invasive species such as dog-strangling vine, burning bush, creeping bellflower, barberry, periwinkle, miscanthus and lily of the valley.

Mow and rake your lawn as needed, but to create critical pollinator habitat, reduce the amount of lawn you actually have.

Our biodiversity crisis requires more from us than simply neglecting the lawn for the month of May.


Christina Keys volunteers with the Manor Park Community Association to remove invasive species and establish native plant gardens across the neighbourhood.


This article originally appeared in the Manor Park Chronicle.


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