Why Native Plants?
I used to believe that organic gardening was the best and only way to support pollinators and wildlife, until I learned about the harm exotic plants can have on ecosystems. Gardeners and landscapers often use exotic plants because insects and wildlife won't eat them. The reason is because they cannot bypass the chemical defenses of exotic plants - as they did not co-evolve with them.
As a result, exotic plants decrease the amount of insects in your yard which negatively impacts birds and other wildlife that depend on them as a food source. Birds require HUNDREDS of insects and caterpillars PER DAY to rear their young.
Pollinators and wildlife in North America co-evolved with our native plants. This interdependent relationship ensures their mutual survival. In turn, wildlife and pollinators perform services that help humans, such as crop pollination and pest control.
A study in 2019 found that bird populations in North America have declined by an average of 30% over the past fifty years – amounting to three billion less birds in our skies. (3 billion is about TWICE the entire population of China.) A year after this report was published, there were accounts of migratory songbirds falling out of the sky across the southwest. Researchers performed autopsies on the birds and determined that 80% died of starvation mid-flight. Since migratory birds need to stop and refuel every few days, the mass die-off signaled an absence of food sources along their flight path.
20 years ago, Monarch butterfly populations in North America were plummeting. Today, the population of Eastern Monarchs are just 20% of previous numbers. Western Monarchs have dwindled to just 0.01% of their historic populations and are on the edge of extinction. Monarch caterpillars rely on milkweed as their sole food source.
For many years, scientists have been raising the alarm about the decline of bee populations. Of the 4,000 bee species that are native to North America, 1 in 4 are at risk of extinction. Thousands are presumed to be extinct. Below is the Rusty Patched Bumblebee, a once common bumblebee in North America - now on the endangered species list. There are many native plants, trees, and shrubs you can grow that will support our native bees.
Deforestation, urban sprawl and industrial agriculture destroys essential pollinator and wildlife habitat.
Massachusetts loses 40 acres of forest every day with severe losses seen on the South Shore. Since forests are home to 80% of wildlife, deforestation and urban sprawl displaces wildlife and places them at risk of extinction.
Unfortunately, landowners also contribute to biodiversity loss and species extinctions by growing exotic plants and cultivating lawns.
Exotic plants can become invasive and outcompete native plant communities which destroys habitat and disrupts food webs. The prominent invasive plants in New England have powerful root systems that destroy riverbanks and vines that strangle trees and degrade forest ecosystems. In coastal areas, a dense invasive grass is displacing wildlife that nest and forage in wetlands. Invasive plants are a leading cause of plant and animal extinctions worldwide.
Exotic and invasive plants can also be harmful to human health. The popular exotic (invasive) Barberry shrub is known to create a microclimate that allows tick populations to thrive and increase exposure to Lyme disease.
Though lawns do not provide food or habitat for wildlife or humans, they cover 40 million acres of the United States. Water usage for lawns in the United States averages 9 billion gallons per day, making it the nation’s largest irrigated crop. Synthetic fertilizers add excess nitrogen into the environment and cause toxic algae blooms that kill aquatic life and pose serious health threats to humans and animals.
Commonly used lawn and garden chemicals linked to cancer in humans is also a leading cause of pollinator and bird population declines. Just one seed from a pesticide-treated plant can kill a songbird.
Native plants and insects are essential to the ecosystems that support human life. Aside from providing food and wildlife habitat, trees, shrubs, and perennial plants provide oxygen, storm buffering, flood control, water purification, climate regulation, and carbon sequestration. Many of our native plants have edible fruits and striking fall color.
The butterflies and moths that native plants attract are a food source for wildlife. As wildlife feed on insects, they perform pollination and pest control. When wildlife forages for fruit, they disperse seed and assist in forest establishment. Native plants attract hundreds of species that pollinate wild plants as well as agricultural crops that sustain human lives.
In order to attract more insects and wildlife into our gardens, we must increase the number of native plants. Ecologists have found that landscapes with at least 70% native plants can adequately sustain the complex food webs that support insects and wildlife.
Individuals, businesses, farmers, landowners, schools, and the public sector can all make a positive impact just by increasing the number of native plants in the landscape and eliminating the use of herbicides and pesticides. If every lawn in Massachusetts was converted into a native plant garden, the total area would be larger than the Grand Canyon National Park.