Have you heard about native plant gardening? It’s becoming more popular, but many people don’t understand what the big deal is. Native plants are species that naturally occur in a region, rather than exotic plants brought in from other regions or countries. Many popular plants used today in landscaping are not native. These non-native plants are grown because they are beautiful or useful, but if they dominate they can degrade the natural habitat by breaking the food web or becoming invasive and out-competing native plants. Native plants have evolved in that specific environment, so the benefit of growing them is that they will naturally support the ecology of a region and provide the foundation of the food web for pollinators and other wildlife. Keystone native plants serve an even more important role in ecological balance.
What Are Keystone Plants?
Each ecoregion has native plants known as “Keystone Plants”. These keystone native plants are the pillars of the local food web, providing food and habitat for insects and the birds that feed on them. These important plants have earned their name because they feed the most species. We rely on those insects and birds to pollinate our food crops. Just like removing the “key” stone in a Roman arch, if these keystone plants are removed, the whole ecosystem will crumble. Humans depend on a functioning food web and ecosystem, despite the growing disconnection from the natural world that keeps us alive. The good news is that gardeners can make a big difference by strategically planting more of these plants.
The Importance of Keystone Plants
Researchers are learning more about how vital these species are every day. Dr. Doug Tallamy, an entomologist with the University of Delaware, is probably one of the most well-known authorities on keystone species. If you want to dig further into which plants are keystone native plants for your region, you can visit his website Homegrown National Park. His research shows that 14% of native plants (the keystones) support 90% of the butterfly and moth species. Horticulturist Jarrod Fowler has learned that roughly 25% of the 770 species of bees native to the Eastern United States are pollen specialists and only feed from a tiny portion of keystone native plants. These are just a couple of examples of how important these keystone species are.
What Are Ecoregions?
Many gardeners are familiar with the USDA hardiness zones that are based on the average lowest winter temperature in an area. Ecoregions are based on commonalities among geology, land formation, soil, vegetation, climate, land use, and rainfall. There are 15 Level 1 ecoregions in North America with 12 Level I ecoregions in the continental US. These are then further broken down into Level II, Level III, and even Level IV subregions.
The Level 1 ecoregions in North America are as follows:
- Arctic Cordillera
- Tundra
- Taiga
- Hudson Plains
- Northern Forests
- Northwestern Forested Mountains
- Marine West Coast Forest
- Eastern Temperate Forests
- Great Plains
- North American Deserts
- Mediterranean California
- Southern Semi-arid Highlands
- Temperate Sierras
- Tropical Dry Forests
- Tropical Wet Forests
Regions 1 through 3 are mostly in Alaska and Northern Canada, and regions 13 through 15 are mostly in South America. There is some overlap within the southernmost parts of the United States. For example, the Everglades in Florida is a part of the Tropical Wet Forests ecoregion. Don’t worry – you don’t have to become an expert in ecoregions to make a difference. The most important thing is to know your Level 1 ecoregion, which is the broad region where you live. That will help you find resources to help you choose which plants to grow.
Which Native Plants Are Considered Keystone Plants?
Keystone natural plants consist of trees, shrubs, herbs, and flowers. We won’t go into an exhaustive list here, but there are some popular North American keystone plants you might be familiar with. Examples include the Common Evening Primrose (Oenothera biennis) and Black-Eyed Susan (Rudbeckia hirta), which are keystone species in the Northern Forests and several other regions. Common Sunflowers (Helianthus annuus) are keystones in the Northwestern Forested Mountains. Blanket Flower (Gaillardia pulchella) is a keystone plant in the Great Plains. Many different species of oak trees and goldenrods are considered keystones across many regions.
How You Can Help
Urban sprawl, modern farming methods, and pesticides are causing harm to the ecosystem that has always supported us. Vital populations of insects like bees and butterflies as well as birds have been declining at an astounding pace. Since 2007, some bee populations have dropped more than 80%. We have lost nearly 3 billion birds since 1970. America has over 63 million acres of lawns. Just imagine the benefits of restoring those lawns to a more natural state by planting keystone native plants! A yard filled with native plants will help you to grow a more successful garden because they will attract pollinators to pollinate your vegetables as well as natural predators that will control pests.
Helpful Resources
If you would like to learn more about which native plants are considered keystone species in your region, or just want to learn more about supporting the birds and the bees, here are a few resources we think are terrific:
- Homegrown National Park - Dr. Doug Tallamy’s website - he offers excellent plant guides by region and other resources
- The Xerces Society for Invertebrate Conservation - This is an excellent site for learning about native plants by region
- The National Wildlife Federation - Has excellent resources for creating native plant habitats
We want our customers to be successful in their gardening endeavors and are always on the lookout for more quality heirloom native plant seeds to offer you. When planning your gardens for 2025 we hope you will consider adding more keystone native plants to your environment.
