Today I worked in the front yard during a beautiful fall day finally attacking the area of myrtle that is threatening to overtake a significant portion of our postage stamp yard in the city. I grew up loving myrtle- the leaves were shiny and strong and seemed to always look its best regardless of the season, so for years I let it grow.
However, since hearing Dr. Doug Tallamy, professor and chair of Entomology and Wildlife Ecology at the University of Delaware, I realized that I had grown up with misperceptions. Myrtle or periwinkle (vinca minor) is considered an invasive species because it creates a dense system of roots that chokes out the native plants in our area.
I used to think,"That's not so bad, it crowds out the weeds that make the garden so untidy." Now I've learned that the native species are the ones that provide food sources for insects and the birds. Our native bugs and birds have evolved together with the native plants and trees of our Indiana habitat. These plants provide nectar for the bees and birds and leaf material for the insects. In particular, native trees are the supermarket for a huge variety of caterpillars. When birds are raising their young, many have a main diet of caterpillars and other wriggly creatures. It is necessary to have pounds of caterpillars each day to fill the young birds with a high protein diet during a crucial growth period. Without this dietary smorgasbord, the birds will eventually die out. Often home owners choose trees that easily available and inexpensive, but many trees and shrubs at local nurseries are non-native species that do not provide any food support to the native birds and other animals.
The other day, I walked past some of our plantings around the Meetinghouse. I noticed that the native flowers that Terry Trierweiler planted in the courtyard were buzzing with activity. I saw bees and butterflies moving in and out around the flowering plants. I noticed the same lively activity in our butterfly garden (Forgive the messy appearance, Friends. we will clean it up in the spring!) However, the other areas seemed quiet and still. Nothing was happening.
By considering what we plant in our yards, we can have a huge impact on the biodiversity of our neighborhoods. For instance, oaks, willows and cherry trees can support over 450 species of lepidoptera (moths and butterflies). If everyone in the United States, reduced their lawnsize by 50%, and replaced with native species plantings, we can restore to native habitat more than all the land dedicated to our national park system.
But today, just take a look at your yard. Is there one plant that you can substitute with a native plant? The birds will thank you.
Mary Blackburn
Resources:
Bringing Nature Home, Doug Tallamy (2014) Timber Press
InPAWS-Indiana Native Plant and Wildlife Society
Keep Indianapolis Beautiful
www.invasivespecies.IN.gov