We live on the knife’s edge - that edge being the delicate balance of ecosystems of this, our earthly home. We can see all around us the results of introducing (purposefully or inadvertently) invasive non-native plants to our gardens and surroundings - Bradford Pear, privet hedge, Elaeagnus, Kudzu, Mahonia, Nandina, multiflora rose, Mimosa and pretty much anything with “Japanese” in its name. These plants have rampantly invaded our fields and woods, crowding out the native plants that provide food and habitat for wildlife.
Why does this matter? The birds eat the seeds and berries of these plants - so they must be okay, right? Indeed, that is how they spread so profusely! The problem is, these non-native plants do not support one very important population - insects. Not only do insects provide important crop pollination, without which our food supply would be sorely diminished, they provide at least 95% of the food for baby birds. Insects, in all their stages, provide food for adult birds as well as for a multitude of other fauna. Many imported plants are selected for precisely the reason that they are insect resistant. Our native insects do not feed on these plants, thereby creating a food desert for some forms of wildlife. Not only can foreign plants become invasive, piggy-backing on these plants are weedy seeds and diseases that can sneak in tucked away in the soil, on the foliage and roots, and in the packaging. In short: planting non- native plants can create a plethora of unintended negative consequences.
Ecosystems are made up of interconnected parts, thus when one part fails, it has a ripple effect of failure. This is often not immediately noticeable, but little by little we may begin to notice small things: “this year there aren’t as many butterflies as in the past”. Farmers may mention that their crops are not doing well due to the lack of bees and other pollinators. We being to notice fewer birds – except for starlings and English sparrows, which are often unwelcome visitors. It becomes apparent at some point that something strange is afoot. We begin to suspect that there is more going on than meets the eye. Something has disrupted the usual order of things. Is there a failure at some point in the balance of the ecosystem?
Some experts have suggested that we consider an about face and do away with sterile lawns that provide no benefit to the environment (or are even detrimental to the environment) and plant gardens of native plants that provide food and shelter for wildlife. In addition, there are several non-native plants which have a history of “playing well with others” in that they do provide food and shelter for wildlife along with the natives, and do not become invasive. So, using common sense and due diligence, you can add a non-native plants to your garden. When planting, it is beneficial to provide structure by way of tiers or different levels of plants. Low-growing plants such as perennials and small shrubs provide safe hiding places for small animals. Larger shrubs and small trees provide a way for baby birds to access to taller trees and places for all birds to escape from danger (as much as I admire my neighborhood hawks, I do want to give the little guys a fighting chance!). Improving garden soil naturally with leaf mulch and compost is a great place to start when planning a new bed or re-working an old one. Mulch is the magic wand for environmentally healthy soil. Then, at the end of the summer growing season, leaving the dried plants with their seed heads (messy as that is) provides food and shelter continuously throughout the winter for insects, birds, and other small animals.
Those of us who garden should do our best to provide information and education to the public about the benefits of native plants and the hazards of non-native invasive plants to our environment and to wildlife we wish to protect. There are steps we can take to improve the future of our environment, such as foregoing buying imported plants, campaigning landscapers to stop planting these invasive non-native species, and asking nurseries to stop importing and selling such plants. We can lead the way by shopping for and utilizing native plants in our gardens. The good news is that we can begin the process now to reverse the imbalance created by non-native plantings and help ensure the survival of wildlife by planting native plants. Conversely, if we do not take this danger seriously, begin to act, or fail to follow through, the imbalance and the attendant failures in our delicate ecosystem will continue to be a serious problem. For our own good, may we begin to dedicate ourselves to being part of the solution, rather than perpetuating the problem.
*For further reading on this subject I recommend the book “Bringing Nature Home” by Douglas Tallamy