Mulching During Winter?


Mulching During Winter?
What happens if mulching is done during winter, since we’ve had so little snowcover during this GTA winter?
Specifically, if I add mulch on top of any weeds remaining from the past spring/summer/fall, will the remaining weeds be nourished, and be stronger in spring, or will the weeds diminish because of lack of sunlight?


Adding mulch to your garden has a number of benefits. Mulch helps to control weeds by preventing the germination of weed seeds. In the summer, a layer of mulch conserves moisture in the soil. In the winter, the mulch will insulate the ground keeping the soil consistently cold and avoiding the freeze-thaw cycle that can cause plants to heave out of the soil. Over time, mulch will break down adding organic matter and improving the water-holding capacity of the soil.

Mulch for winter protection is best applied in the late fall, after the ground freezes and before any significant snowfall. Given the lack of snow cover right now in Toronto you could certainly add mulch to your garden at this point. You’ll gain the insulating quality during the remaining winter months and weed suppression in the spring. Note that while a good layer of mulch prevents the germination of weed seeds, it will not kill the roots of any perennial weeds (for example, dandelions) that are already established in your garden bed. The mulch does slow them down as they stretch up through the mulch to reach the sunlight and will make it easier for you to root them out.

As always when applying mulch, ensure the mulch does not touch the crowns or stems of plants to avoid rot caused by the moisture-retentive quality of the mulch. Leave about an inch (2.5cm) around the plant.

If you’d like to read more about using mulch in your garden, the City of Toronto has put together a good fact sheet on gardening with mulch. Click here to access the article.