What Makes a Plant Native?
Native plants are species that are indigenous to a particular geographic region. They aren’t usually defined by state, political boundaries, or the growing zones that many gardeners refer to. Instead, they are assigned “ecoregions”. These ecoregions are areas determined by environmental conditions such as soil, climate, landforms, hydrology, etc. Native plants in a given ecoregion have formed unique relationships with the wildlife that have lived there over thousands of years, long before the first European settlers arrived in the US. If you want to know what plants would do best where you live, consider finding out which ecoregion you live in and plant accordingly! There are even sites like this one where you can look up a plant by name and learn if it is native to your area.
Want to take things a step further and have the most impact even in a small space? Select keystone plants! They are like the glue that holds a habitat together. Research shows that keystone plants support specialist bees and the caterpillars of 90% of our butterfly and moth species. Those caterpillars are essential food for birds. Did you know that Chickadees need to find 350-570 caterpillars daily over the course of 16-18 days to raise their chicks? That is an astounding 6,000-9,000 caterpillars for just one clutch of Chickadees! The more keystone native plant species you are able to include in your landscape, the more your landscape will become helpful habitat that can be the backbone of an important food web.
Benefits Beyond Beauty
One of the benefits of planting with native plants is that they provide nectar, pollen, berries, and seeds for wildlife. Numerous bird species must stock up on nutritious berries before migration events. Oftentimes, ornamental exotic plants simply do not provide the same nutritional value to birds or insects. As a matter of fact, the caterpillars of many butterflies and moths must have access to very specific native host plants to eat in order to reach adulthood. Adult butterflies may visit a non-native plant for nectar, but many of them can only lay their eggs on specific native plants. Why? Because their larvae (caterpillars) must consume the plants that they have been adapted to for thousands of years. A prime example frequently used is the relationship between monarch butterflies and milkweed. We love to see monarchs visit our yards, but unless they have access to milkweed they cannot reproduce! No milkweed, no monarchs.
There are other benefits to consider beyond food/shelter for wildlife. Did you know that the deep root systems of some species can also help protect our soil and prevent erosion or mitigate flooding. Not to mention they have the ability to improve air quality as they sequester (remove) excess carbon from the air. Another added bonus? Native plants do not require the steady stream of fertilizers that lawns often demand. Adding more native plants in place of lawn can also minimize the need for lawn mowers and other gas powered equipment.
The Best Part? Biodiversity!
Native plants promote amazing biodiversity. What does that mean? Think of it as “variety of life”. Beneficial insects and pollinators are drawn to native plants. Birds, amphibians, and reptiles are given life-sustaining energy by consuming those insects or the seeds/berries those plants produce. In a habitat rich with native plant species, mammals are able to find food and shelter that is perfectly adapted to meet their needs. The more varieties of native flowers, shrubs, trees, and grasses you have, the more life you’ll find in your own yard. For far too long we have pushed nature to the outskirts of our neighborhoods. We’re learning that those actions have had serious consequences. And those consequences have a direct impact on the human race, not just the wildlife that inhabit our precious planet. Together, we can make the world a better place…one native plant at a time!
A Word About Invasive Species
Today, many native plant communities are threatened by development, human activity (such as irresponsible pesticide use), and invasive species. Invasive species can be plants like japanese honeysuckle, garlic mustard, or knotweed. They can also be animals or other living organisms. Asian Jumping Worms are becoming a real issue that is having a profound impact on US forests. The one thing they all have in common is that they were brought here (intentionally or inadvertently) from somewhere else and have the ability to cause great economic or environmental harm to an area. Many of these introduced species have few natural enemies, spread very quickly, and can displace native species. This creates environmental upset and imbalance, oftentimes to the detriment of habitat areas and the wildlife they support. You can do your part to correct mistakes of the past by avoiding the future purchase of invasive plants, removing invasive species from your property and replacing them with native plants.
Some plants whose origins are from another country are much loved by gardeners and are not known to wreak havoc in an ecosystem. A few that come to mind are peonies, daffodils, tulips, etc. They don’t tend to travel too far away from their original spot. Such plants neither greatly benefit our environment nor do they harm it. They have ornamental/sentimental value, but limited value in an ecosystem. You might think of these plants as non-native neutrals. Are there better plant choices for our landscape from an ecological perspective? Certainly. Should you rip out your family heirloom peonies that have been passed down through several generations? That’s really not necessary unless you feel so inclined. On our twenty-two acre property, we reserve space for a few well-behaved non-native neutrals that hold sentimental value to us. I have spoken with individuals who refuse to have a single non-native plant on their property. It is up to each person to determine their own gardening priorities and act accordingly.
One thing to keep in mind is that most of the plants sold in garden centers are ornamental hybrids or exotics from another country. Though hybrid double-flowering species are gorgeous, the dense overlapping of petals can make it difficult for pollinators to access nectar/pollen. Plants bred to have red or very dark colored leaves can be unpalatable to wildlife and thus ineffective as a food source. That can seem desirable to those wanting a pristine landscape, but the reason we plant native plants is to support wildlife that may need to utilize those leaves.
Some of these altered species can hybridize with wild native plant populations, thus affecting the genetics of that local plant community. At times, exotic species have escaped the home garden setting and invaded natural habitats to the detriment of the creatures that live there. At that point, they are considered invasive. It can be years down the road before a supposedly benign plant has been discovered to be invasive (callery pear, burning bush, barberry). Always do your research on a plant, it’s origin, and behavior before you add it to your yard. Also keep in mind that when we fill our landscaping or even entire communities with non-native ornamentals in an effort to “keep up with the Joneses”, we essentially create a vast food desert for local wildlife. It’s time for a shift in our mindset as individuals and as a society!