Hi! Welcome to #WorldWednesday! Now that spring is right around the corner, many of us are anxious to head out to the garden and clean things up. This is the time of year we start to notice the dead ornamental grass stalks, spent perennial stems and autumn leaves that collected over the winter season. Now that the days are starting to warm up, gardening chores are back on the "to do" list. Let's talk about best practices when doing spring garden clean up.
Step 1: Cut, bundle and tie. In early spring, many insects are still in diapause (a physiological state akin to hibernation). In other words, they're still sleeping. Lots of beneficial insects, including pollinators like tiny native bees and pest-munching predators like syrphid flies, lacewings, and parasitic wasps, spend the winter hunkered down in hollow plant stems either as adults or pupae. Cutting down the dead plant stems too early in the spring will disturb them before they have a chance to emerge. Wait as long as you can to do your spring garden clean up. Ideally, you should wait until the daytime temperatures are consistently above 50 degrees or as an alternative to delaying your spring garden clean up, here are two options:
a. Toss cut perennial and woody plant stems onto the compost pile very loosely, or spread them out at the edge of the woods. Many of the insects taking shelter inside the plant stems will still be able to emerge when the time is right. When you cut off the plants, leave about 8 inches of stubble behind. These hollow stems will serve as overwintering sites for future generations of insects and the new growth will soon hide them.
b. Another option is to take the cut stems and gather them into small bundles of a few dozen stems each. Tie the bundles together with a piece of jute twine and hang them on a fence or lean them against a tree on an angle. Again, the insects sheltering inside of them will emerge when they're ready. An added bonus of this method: More insects, especially native bees, will move in to the stems and possibly use them as brood chambers all summer long.
Step 2: Do a careful leaf clean up. Again, waiting as long as possible to rake leaves out of perennial beds is the best idea. Hold off on your spring garden clean up until daytime temperatures consistently reach the 50s if possible. Scores of beneficial insects-ladybugs, assassin bugs, and damsel bugs, for example-hunker down for the winter in leaf litter as adults. Others do so as eggs or pupae. And, adult butterflies, such as morning cloaks, question marks, and commas, nestle into leaf litter for the winter. Luna moths spend the winter in cocoons that look just like a crinkled brown leaf. As you clean up your leaves keep a sharp eye out for these insects and do your best not to disturb them.
Step 3: Don't mulch...yet! There are also many beneficial insects and pollinators who overwinter in soil burrows as either eggs, pupae, or adults. Some examples include the hummingbird clearwing moth, soldier beetles, and many native bees. Covering the ground with a layer of mulch too early in the spring may block their emergence. Hold off on mulching chores until the soil dries out a little and the weather warms.
Step 4: Prune with great care. If part of your spring garden clean involves pruning back woody perennials or shrubs, keep a sharp eye out for cocoons and chrysalises. Some of our most beautiful moths and butterflies spend the winter in a delicate cocoon dangling from a branch, including the swallowtails, the sulfurs, and spring azures. Allow any branches with a cocoon or chrysalis present to stay intact. You can always cut them back later in the season.
By taking your time and doing it right, you and your garden can reap the many benefits of a healthy population of pest-munching beneficial inspects and pollinators. Check back next Wednesday for more tips and tricks. See you soon! Warmly, Susan