Plants that are native to our region provide essential resources for supporting the life cycle of native pollinators.

Moths and butterflies lay their eggs on leaves. When the eggs hatch, the baby caterpillars eat the leaves. Thousands of caterpillars are needed as food for just one nest of baby birds. The vast majority of caterpillars can eat the leaves only of specific native plant species. These are host plants.
Bees collect pollen from plants to store in their nests. Most native bees are solitary, and make their nests in tunnels in the ground or in wood. When the eggs hatch, larvae eat the pollen. Most bees can only eat pollen from specific native plant species – these are the host plants for bees.
To feed the next generation of pollinators, host plants are necessary.
This means that when you see holes in leaves, it is good news! Your plants are feeding young caterpillars, which will either become food for birds or transform into moths and butterflies, which will pollinate plants.
To have enough food to support populations of insects in numbers that are sufficient to pollinate plants and also feed nesting birds, we need at least 70% native plant biomass in our neighborhoods. If we have less than that, baby birds starve, and plants go unpollinated and will eventually die out.   Trees and shrubs, with their large volume of foliage, are essential components of a thriving ecosystem that can support pollinators and other species.  

Keystone species are plants that support a large number of caterpillar species and have a widespread impact on food webs. We recommend this Keystone Plant Species for Landscape Use.