Take a Walk on the Wild Side of the Garden

Written by Brittany Killingbeck, Stewardship Technician at the Hamilton Naturalists' Club, for the April 2025 Wood Duck.

With the arrival of warm spring days we are inevitably drawn outside to tend to our gardens and yards, but the traditional approach - removing leaves, cutting back vegetation, spreading mulch, maintaining the lawn, and filling yard waste bags for collection - is frankly bad for nature, especially insects which are essential for life.

Insects pollinate wild plants and agricultural crops, help control pests and maintain the natural balance, improve soil health, clean up dead or decaying matter on land and in water, are a crucial part of the food web, and act as bioindicators for the environment. They provide invaluable ecosystem services that keep nature (and us) alive. Unfortunately, insects are declining worldwide. Multiple factors like habitat loss and fragmentation, pesticides, pollution, disease, and climate change are driving population declines in even the most remote areas of the globe. As individuals we can work together to make a difference for our local insects, starting in our own backyards.

We can't see many insects right now, but rest assured most are right where we left them in the fall - in our gardens. When we clean up the yard we’re cleaning up those valuable insects too, so if we want to support biodiversity in our backyards we need to shift away from pristine landscapes to something a little more wild. That doesn’t mean it needs to look neglected though! With some strategic adjustments to our maintenance activities we can keep a neat, bylaw complying yard that supports insects while saving ourselves time too.

The common advice for spring cleanup is to wait until the daytime temperatures are consistently above 10-15°C with no risk of frost, after which the insects will have left their overwintering spots and it is safe to clean up. However, we know that different insects emerge at different times of the year and the insects that take flight later will still be inside the plant debris we plan to remove. Instead of cutting, raking, and bagging away the old vegetation:

• Leave stems intact or trim pithy/hollow stems to a height of 8-24 inches, which will be quickly concealed by new growth. Cut stems can be scattered around the garden or placed in bundles in inconspicuous places rather than tossed into yard waste bags, which allows any resident insects to emerge when they’re ready and will be reused as a natural “insect hotel."
• Leave woody stems, sticks and logs at the back of the garden to rot over time, creating perfect nesting habitat for many insects.
• “Chop-and-drop” non-diseased leaves and stems around the base of the plants, creating a natural mulch that will fertilize the soil.
• Leave the leaves, permanently. Many butterflies and moths overwinter as caterpillars or pupae in leaf litter, and leaves insulate the ground for bees and bumblebees. Use your best judgement and pick a method that works for you, like leaving a thin layer of leaves on the lawn, raking them into garden beds around the plants to act as natural mulch, or creating designated leaf piles to break down. It doesn’t have to be perfect, just keep as many leaves as you can.​

Another consideration is that a majority of our native bees and bumble bees nest in the ground and need bare soil as suitable habitat. So skip the tilling and heavy mulch chips in favour of undisturbed bare soil and natural mulches like leaves, plant debris, and sedges that create wonderful nesting habitat.

Now let’s address the elephant in the room - lawns. Over the last decade the “No Mow May” campaign has become popular in part due to its (over)simplicity and there have been many discussions evaluating its effectiveness. Anyone can participate by delaying mowing their lawn, which does allow some flowers to grow among the turfgrass and provide early-season sources of nectar. However, the species that typically grow (ex. dandelions, clover) are non-native plants that are less nutritious than native plants and do not provide good quality habitat. After the four weeks are up mowers and leaf blowers are powered up to restore the lawn’s aesthetics, destroying the minimal habitat created in the process. The campaign’s greatest benefit is arguably its ability to spark conversations, break social norms, and encourage both individuals and municipalities to explore ecologically-friendly management practices. No Mow May should be considered a stepping stone, not the destination.

A more intentional approach to supporting insects is to replace part of the lawn with a diverse native plant community, which will provide food, shelter, nesting habitat, and overwintering sites for insects. Some people dive head first into converting their entire yard while others expand the garden edges little by little each year. For maintaining the lawn you’d like to keep, try to reduce mowing to every two weeks throughout the growing season, raise the blades to keep the grass at least 8 cm tall, and skip the pesticides.

If you’ve been inspired to create a native plant garden or already have one established in Hamilton, you can certify your pollinator garden through our collaborative Hamilton Pollinator Paradise Project and receive a “We’re Feeding Pollinators” sign to display and spark discussions with friends and neighbours. Happy gardening!