How to plan a pollinator garden that actually works

Why pollinators matter

Most of what flowers was built around an animal's visit. A 2011 study in the journal Oikos by Ollerton and colleagues estimated that about 87.5% of flowering plant species are pollinated by animals, around 78% in temperate regions.

Our food depends on them too. The USDA Forest Service notes that almost 80% of the world's roughly 1,400 crop plants require animal pollination, and that more than 150 food crops in the United States depend on pollinators.

Meet the native bees

When people picture bees, they usually picture honey bees. But the Xerces Society counts about 3,600 native bee species in North America north of Mexico. About 70% of them nest in the ground, and about 30% in cavities like old beetle tunnels and hollow stems.

Many are in trouble. Xerces names habitat loss, pesticides, climate change, and introduced diseases as causes of decline, and reports that 28% of bumble bee species in Canada, the U.S., and Mexico fall into an IUCN threatened category.

The four principles

The Xerces Society, a pollinator conservation nonprofit, boils a good pollinator garden down to a few principles:

• Grow flowers with overlapping bloom times, so there's food from spring through fall.
• Provide places to nest: bare ground, brush piles, hollow or pithy stems, and host plants for caterpillars.
• Avoid pesticides. Insecticides are the most harmful, herbicides remove flowers, and some fungicides can harm bees too.
• Choose native plants, which are usually the best food and shelter for native pollinators.

Start with your region's plants

A good list does most of the work. Xerces publishes pollinator plant lists you can filter by state or region, covering nectar and pollen plants, caterpillar host plants, and plants for specialist bees. Pollinator Partnership offers free ecoregional planting guides: enter your ZIP code and download the guide for your area.

Then plant in groups. Xerces notes that clumps of native flowers attract more pollinators than single plants scattered around.

Skip the neonicotinoids

Some of the most common garden insecticides are among the most harmful to bees. A Xerces Society guide explains that neonicotinoids are systemic: the plant absorbs them and carries them into its pollen and nectar. Some can last in soil for months or even years, and garden products used as labeled can reach concentrations dozens of times higher than on farm crops. Small doses slow bumble bee colony growth and reduce the number of new queens.

Check labels for imidacloprid, acetamiprid, dinotefuran, clothianidin, and thiamethoxam, and ask your nursery whether plants were treated before you buy them.

Monarchs and the right milkweed

Monarch caterpillars eat only milkweed, but the kind matters. Xerces recommends milkweeds native to your region, and its Milkweed Finder lists local seed sources. It does not recommend tropical milkweed, which stays green through winter in mild climates, can build up a parasite that infects monarchs, and can encourage monarchs to breed instead of migrate. Where it's native, butterflyweed is a good alternative.

Xerces also advises against planting any milkweed within a mile of monarch overwintering sites in coastal California.