Okay, I agree this isnt a very sexy photo to start off with but it does tell a story. Weve had some crazy temperature swings this spring here in the upper Midwest, (including two inches of snow yesterday) and I have been putting off cutting down any plant material in my landscape.
As gardeners we are told to clean up our gardens in the fall, cut down plant stems (except ones that provide winter interest) and rake/blow every last leaf out of our yards. What we are in fact doing is removing the overwintering habitat of insects that the wildlife (birds, amphibians, reptiles, spiders) will need next spring to feed upon and rear their young.
So back to the first photo, theres leaf litter, rocks, grass blades and plant stems. The only thing missing is some nice logs on the ground with a bit of loose bark to curl up underneath.
Consider the Life Cycles of Insects
Insects can overwinter in several life stages including adult form, egg, nymph, larval and anything in between. Many insects undergo a period of suspended development called diapause, similar to hibernation. They seek out protection under leaf litter, tree bark, rocks, clumps of grass or plants, logs on the ground, and in hollow plant stems. (BugGuide.net) Some of earliest emerging butterflies like the Mourning Cloak and Eastern Comma overwinter in adult form and need somewhere to weather the cold winter temperatures.
In the second photo (late April/early May), the plant material on our front hillside has been cut down and almost all of it left in place as a mulch around the plants. I do take away the large stiff stems of Cup Plant (Silphium perfoliatum) for example, because theyre hollow and make excellent solitary bee nests. Just cut to lengths of 12 inches, bundle togther and hang in a sunny location.
Depending on the species of insect, the life cycle development can vary greatly but you can make a huge difference by leaving the plant material up for the winter and not removing the leaf litter. I attended a talk this winter by University of Minnesota Entomologist Vera Krischik, who said that in the spring it is important to wait until temperatures reach at least 50 degrees F to ensure that overwintering insects have emerged.
In the third photo, (mid August) no plant debris from the previous year is visible as it gets covered with the growing perennials.
Whats So Great About Encouraging Insects in My Yard?
Insects are the phytoplankton of the non-aquatic world. They are the foundation of the entire foodweb for wildlife. Native plants play an equally important role in this foundation, providing the habitat, nectar and food for insects.
We have incorporated logs into our naturalized woodland specifically for insects. They provide excellent habitat and woodpeckers will come and peck away at the logs seeking out the insects. Logs on the ground also help retain soil moisture native shrubs and perennials that were planted near logs have grown almost twice as large as others not planted near a log.
Not sure if you like the look of a log in your garden? Plant native shrubs and perennials around it so it will be become covered in the summer months.
Adding or leaving leaf litter, logs, plant debris and rocks in your garden will provide excellent insect habitat and ultimately attract more wildlife. You cant build a house without a foundation and you cant garden for wildlife without fostering the entire life cycles of insects.
© 2011, Heather Holm. All rights reserved. This article is the property of Native Plants and Wildlife Gardens. If you are reading this at another site, please report that to us