Are you like a kid in a candy store when you go plant shopping? So many choices! But after many years of choosing plants based only their beauty, I discovered that I’ve been doing no favors to the birds and butterflies I was trying to encourage, because I was purchasing mainly non-native plants.
Once established, native plants will provide a beautiful season of blooms with little care.
What is a native plant? Native plants are plants that have historically grown in an area without having been introduced directly or indirectly by humans. They have co-evolved with the area’s insects and birds as part of the food web.
The bad news: We are in the middle of a mass extinction, with approximately a 30% loss of birds and insects since the 1970’s. The causes include climate change, changes in agricultural practices, habitat loss, and modern gardening and lawn care practices. If this loss continues it will have serious ripple effects throughout the world’s food web, including our own.
The good news: Many people are coming to realize that our own yards are a critical part of nature. Instead of planting non-native plants that provide no benefit to the food web, and pursuing the perfect green lawn (via copious applications of insecticides and herbicides), more and more gardeners are seeking out plants that aren’t just pretty.
Caterpillars are critical! Feeding birds is one of America’s most popular hobbies. But with few exceptions, baby birds can’t eat seeds; they need soft-bodied insects. Rearing a clutch of eggs requires around 6,000 to 9,000 insects, with caterpillars the preferred choice. Caterpillars are almost all plant specialists, and most have evolved ways to bypass the defenses of specific plants, and cannot survive elsewhere. (Monarchs and milkweed are just one example of this kind of symbiotic relationship). The plants needed for each species of moth and butterflies’ larvae are called host plants, and providing host plants is the best way to nurture songbirds as well as butterflies and moths. The National Wildlife Foundation has an excellent plant finder database (nwf.org/NativePlantFinder/Plants) that lists plants native to areas by zip code, with info on how many and what species that plant hosts.
This mining bee (Andrena erigeniae) can only use pollen from Spring Beauties to feed its larvae.
Keystone plants– the superstars: There are a number
of plants that are superstars as host plants – we call those keystone plants. In our region, the top trees are oak (host to over 400 species!), followed by American plum (over 300 species); top shrubs include blueberry and willow. Top flowering perennials include the native goldenrods and asters. (See our website for a detailed list).
Are my non-native plants killing the birds and butterflies? There is no need to dig up your hostas or other nursery plants if you enjoy them. There are many non-native plants that provide nectar to butterflies and hummingbirds. It’s only when it comes to laying eggs that specific plants are needed. Of course, if a plant is invasive (Bradford pear, burning bush, purple loosestrife, for example), its fast-spreading habits destroy diversity in wild areas, and it should be removed.
What about the bees?
Our native bees, especially bumblebees, are suffering great losses. (Honeybees are not native, and actually can contribute to these losses by competing with native bees for nectar resources). To help the bees, offer a variety of plants so there are nectar sources throughout the season. Bumblebees use a wide variety of nectar and pollen sources, but there are many small specialist bees that can only feed their larvae with the pollen from specific plants. The keystone plants mentioned above can provide for the needs of many of these specialist bees. Bumblebees and other native bees often are ground nesters, so having areas of open soil can provide habitat.
Native vs. Cultivar: There is some controversy about the use of native plants that have been altered to create a new variety. These plants will be labeled with an additional name in quotes. (For example, a purple coneflower – straight species – would be labeled Echinacea purpurea. A cultivar version might be labeled Echinacea purpurea “White Swan”). These cultivars have been created to appeal to gardeners, but depending on the alteration, they could be less beneficial to insects. In particular, any change to the leaf color or texture could make them inedible or less digestible for caterpillars. Changes to the flower structure might make the nectar or pollen less accessible for pollinators. So if at all possible, choose the straight species.
Your lawn is critical: All this planting of natives will not be helpful if they are surrounded by a lawn that receives applications of insecticides and herbicides and/or spraying for mosquitos. The insects and birds that are attracted by your native plants will be adversely affected!
– Ellie Nowels