What is a native plant and why do they matter?
Plants that occur naturally in a particular region, ecosystem, or habitat without human intervention are called native or indigenous species. They have evolved naturally with local environments, climates and wildlife over thousands of years and offer the most sustainable habitat.
Native plants are essential for the survival of a wide variety of insect species and play an important role in ecological health. Native bees, butterflies and other insects have developed beneficial mutual relationships with native plants and require them for nutritional needs, nesting and larval host environments. Almost all terrestrial birds feed their nestlings insects, usually caterpillars (butterfly/moth larvae). Without native plants hosting these insects, terrestrial birds would not have enough food to rear their offspring.
Native plants require less water than lawns and help prevent erosion. The deep root systems of many native plants increases the soil's capacity to store water, can significantly reduce water runoff and, consequently, flooding.
Native plants do not need fertilizers and pesticides. This helps to keep wildlife healthy and waterways clean for aquatic life.
Native plants are:
- 4x as likely to attract pollinators than exotic plants
- Food for 90% of plant eating insects
- Support 13x more caterpillar species than non-native plants
Pure native plants are better for pollinators then cultivars or hybrids - sometimes called nativars if the cultivar is derived from a native species. Cultivars are bred for particular characteristics such as colour, scent, shape or size. These altered plant species usually offer a more complicated flower, restricting pollinator access and can also have less nectar or pollen.
There is considerable controversy over native vs. cultivar plants. Cultivars are propagated by tissue culture (asexually), not from seed (sexually), so every cultivar has the same genetic make-up. Since genetic diversity is key to a healthy ecosystem, native species offer the best way to ensure our ecosystems function successfully.
Native plants are the ecological basis upon which all wildlife depend on, including pollinators, birds and people. Without them and the insects that co-evolved with them, bees, butterflies and birds cannot survive.
- It takes over 6000 caterpillars to raise one brood of chickadees
- Native oak trees support over 500 species of caterpillars
- Ginkgos, a commonly planted landscape tree from Asia, host only 5 species of caterpillars
Most of the landscaping plants available in nurseries are ornamental species from other countries. As insects have not evolved with these exotic plants, they cannot use them for nutrition or nesting and the entire food web is disrupted. In addition, many have become invasive pests, outcompeting native species and degrading habitat in remaining natural areas.
With our human dominated landscapes becoming less diverse, it is important to reintroduce native plants that support the most interactions with insects in order to maximize ecological function and ecosystem stability. Native bees need a diverse diet derived from pollen and nectar of many types of native plants to meet their nutritional needs. Studies show that eight or more species of native plants in a landscape increases both abundance and diversity of native bees. A diverse native planting not only supports more pollinators but also attracts beneficial insects. These insects suppress problem pests and provide ecosystem services to all types of landscapes.
What can you do? You can be a land steward by adding native plants to your property!
Even small urban landscapes play an important role in supporting native pollinators when a diverse amount native plants are provided. Try to provide successive flowering plants from spring through fall and choose some species that are host plants to butterflies and moths which support larval development.
Provide nesting sites for bees by leaving bare ground spots, especially on slopes/banks and prevent soil disturbance and compaction. Leave or add dead logs, leaf litter, and rocks with holes. Leave perennial stems for the winter to protect cavity nesting pollinators.
Don’t use pesticides on your plants, and purchase plants from retailers that do not use systemic insecticides during nursery production.
Gardeners and landowners who manage and enhance their landscapes with both pollinator forage plants and nesting areas can support almost as many types of pollinators as natural areas.