When we moved into our townhouse six years ago this fall, it came with meticulously landscaped beds along the house and around the back patio, and a few island beds around trees. Some might view this as dream yard, I viewed it as a great gardening challenge. Most of the plants were non-native, exotic, and invasive shrubs and groundcover. I wasted no time that first spring ripping out the Japenese barberry (Berberis thungbergii), winged burning bush (Euonymus alatus) and Japanese spurge (Pachysandra terminalis) and sending them to the landfill. All of these species have earned notariety on the U.S. Forest Services "Weed of the Week" feature (http://www.na.fs.fed.us/) in the Northeastern Area. In additon, Japanese barberry is ranked #4 on the list of 'Top Forest Invasive Plant Species for the Northeastern Area', ranked in order of priority.
Unfortunately, you can still go out to a local nursery or big box store and buy these plants to put in your yard. I've heard the arguement before, "It's not invasive in my yard, so I'm sure it's ok." Or, "The nursery/store wouldn't sell it if it was bad." Wrong, on both counts. If you spend anytime in forests and natural areas around the state, like I do for my job and recreationally, you would see these plants typically found in people's yards increasingly populating forests and meadows, shading out the native herbs and crowding out the native shrubs. Don't fool yourself that the nursery/store is going to have a concious for you, they are in business to make a profit. If it sells, they'll keep selling it as long as it's legal.
As if being invasive wasn't enough, these plants host no native insects which feed the spiders, reptiles and amphibians, rodents, and 96% (!) of all terrestrial birds that depend on them to survive. Now, some might think, "Great, I don't like spiders or rodents anyway", but those spiders and rodents are part of a foodweb which creates biodiversity in the ecosystems we humans depend on for life. I admit spiders creep me out and I don't like them in my house, and I've been known to kill them if they are in my house (organically, of course) -- BUT, I appreciate and welcome them outside in my yard and gardens. They keep the 'bad' bugs controlled. And I don't have to compromise my checkbook or my family's health using toxic pesticides to control them.
So, with all that new real estate in my yard, I started filling in with native perennials, shrubs and small trees, and increasing my native to non-native ratio to approximately 8:1. Sure, they get munched on a bit by some 'good' bugs, but not enough for anyone to really notice. That's a small price to pay knowing that I'm supplying the local birds, field mice, and yes, even spiders, with the nutrition they need to stay alive, and contribute to the increasing biodiversity of my yard, township, and ultimately, ecosystem.
Biodiversity is what keeps our air and water clean. It buffers extreme storm events, cleans up the waste we create, and it sequesters the carbon spewed into the air by our mowers, cars, etc. Basically, it is what we need more of if we want to survive. As Doug Tallamy put it in his revolutionary book Bringing Nature Home (http://bringingnaturehome.net), biodiversity is not optional, despite the disdain we've given it over the last several decades.
If you want to start increasing the biodiversity in your yard, replace some of your non-native plants with their native counterparts. Instead of an invasive Norway maple (Acer platenoides), plant a red maple (Acer rubrum) and support 285 species of moths and butterflies. Replace that Kousa dogwood (Cornus kousa) with a flowering dogwood (Cornus florida) and support 117 more species. It doesn't take much to start making an impact, and maybe you'll enjoy the song of a new bird this summer, or maybe next year you'll get a front seat view of a nesting wren in your native shrubs.
To help you get started gardening for life, Newtown and Audubon Bird Town has provided the attached list of local native plant sales. You can also contact your local nature centers, Audubon chapter, native plant grower, or conservation district for more information about native plants and plant sales not listed.