…..we have placed garden leaves over our flower beds for the winter for the first time and we are wondering when would be the ideal time to remove them to the benefit of the wee beasties below ??……
Thank you, dear gardener, for writing. Your question says it all, re leaf matter benefiting the ‘wee beasties’.
Yes, insects and bees overwinter in hollow plant stems, and most wild bees live in the ground area beneath. Most butterflies lay their eggs on the very plants that will be eaten by the caterpillars, when they hatch. Some species lay their eggs on the tops of leafs, some on the bottom, some at the leaf axils, some on flowers, and some on stalks. So best if gardeners can let leaves lie undisturbed, for as long as possible!
As you are clearly aware — since you took admirable care to mulch leaves over your garden last fall — fallen leaves are prized as nutritious ‘garden gold’, the best fertilizer after homemade compost. Over-wintered, rotted, leaves are valued for many reasons. The activity of ground ‘beastie’ worms, and the work of decomposer organisms, literally pulls leaves down into the soil, bit, by bit, by bit. Come June or earlier, last year’s leaves are gone.
Date-wise, it is indeed a bit early (March 16, Toronto, ON ) to remove garden leaves, as the beneficial creatures that overwinter are not quite ready to come out of hibernation. Evening temperatures still dip below the zero Celcius mark. Suggest to watch for upcoming days when the soil becomes warm, evening temps are above zero, and you see insect activity on the soil, and even in the air, before tidying up.
In consideration that every garden is unique, and that all plant leaves differ in size and density, please see this Toronto Master Gardener reply to a similar question on this topic of spring garden leaf management.
You, and other gardeners, may be interested to read further from the North American Butterfly Association at this link