Eco Tip: Give Beneficial Bugs a Boost By Holding Back on Yard Cleanup

Marsha Low, Weavers Way Environment Committee

Note: This is a revised version of an Eco Tip published last spring. We’re reprinting it because we consider it to be of particular environmental importance.

With all the snow we’ve had this winter, and with COVID-19 also keeping us indoors, those fortunate to have a garden are likely itching to get out and start doing a spring cleanup. But with the sharp decline in insects (more than 40% of insect species are declining, and a third are endangered), it’s more important than ever to hold off on doing so.

Many overwintering beneficial insects, including pollinators like tiny native bees and pest-eating predators, spend the winter in hollow plant stems either as adults or pupae. Others, like ladybugs and damsel bugs, hunker down under leaf litter. If you’ve left leaf litter and dead plant stems in place to help overwintering beneficial insects, you want to be sure not to remove them too early. In early spring, many insects are still in a physiological state akin to hibernation, so doing your cleanup then will disturb them before they have a chance to emerge.

If at all possible, wait until daytime temperatures consistently reach the 50s before removing leaf litter and dead plant stems. If you want to remove dead plant stems earlier, before new growth starts, consider taking the cut stems and gathering them into small bundles of a few dozen each. Tie the bundles together and hang them on a fence or lean them against a tree. The insects sheltering inside them will emerge when they’re ready.

Remember: Birds need insects, too. With the exception of seabirds, 96% of North American bird species feed insects to their young. Doing all we can to promote healthy insect populations will help birds that visit your yard and encourage them to nest in your trees, large shrubs, or bird houses.

One more tip: Since some beneficial insects overwinter in soil burrows, make sure not to mulch too early in the spring, as doing so may block their emergence. May your garden be filled with the sounds of beneficial insects a-hummin’ and a-buzzin’ this season!