Minnesota & Seasons
Plants for monarchs in Minnesota
Plant milkweed: monarch caterpillars eat nothing else. In Minnesota gardens that means common milkweed, swamp milkweed and butterfly weed, planted in groups of three or more. Then add late-season nectar like blazing star, Joe Pye weed, goldenrod, asters and zinnias to fuel the September migration, and keep insecticides away from the patch.
Start with the host: three milkweeds we grow
Common milkweed (36–60″) is the one monarchs use most in Minnesota — give it room, because it spreads by runners and wants a wilder corner. Swamp milkweed (36–48″) is the better-behaved choice for garden beds, with pink umbels that bees mob — and it doesn't need a swamp, just soil that doesn't bake dry. Butterfly weed (18–30″) is the compact bright-orange one for hot, sandy, front-of-border spots — and the only one of the three that's happy in a pot.
Then feed the flight: late-season nectar
The monarchs you see in September are the super-generation that flies to Mexico, and they need heavy nectar right up to departure. The natives we grow that carry that late shift: Liatris (blazing star), a monarch magnet in late July and August; Joe Pye weed for the back of the bed at 60–84″; common ironweed, royal purple in late August; showy goldenrod and mountain mint, the two busiest plants in any September garden; and wild bergamot bridging midsummer.
Annuals count too. A row of zinnias blooms harder in September than almost any native and monarchs work them constantly — plant them where you can watch. Asters carry nectar to frost and catch the tail end of the migration.
Three habits that matter as much as the plants
Plant milkweed in groups of three or more — a lone stem is hard for a female to find. Skip insecticides anywhere near the monarch patch, including systemic granules, which move into pollen and leaves. And leave some stems standing over winter: other pollinators nest in them, and the seed heads feed birds.
Monarch plants we grow
Common questions
What is the best plant for monarchs in Minnesota?
Milkweed. Monarch caterpillars can only eat milkweed, so it is the one plant that actually produces monarchs. In Minnesota gardens the three to plant are common milkweed, swamp milkweed, and butterfly weed — all native and hardy. Add late-season nectar plants like liatris, goldenrod, ironweed, asters, and zinnias to feed the September migration.
Do I need milkweed to attract monarchs?
Yes. Nectar flowers bring adult monarchs to visit, but females only lay eggs on milkweed, and caterpillars eat nothing else. A garden with nectar but no milkweed feeds passing monarchs; a garden with both makes new ones.
When do monarchs leave Minnesota?
The migration generation typically departs Minnesota through September, with stragglers into early October. That is why late nectar — goldenrod, asters, ironweed, zinnias still blooming — matters so much: it is the fuel for a flight of roughly 2,000 miles to central Mexico.
Should I use pesticides near milkweed?
No. Even pollinator-adjacent insecticide use can kill monarch eggs and caterpillars, and systemic insecticides move through a plant into its leaves and pollen. Plant the monarch patch chemical-free and accept some chewed leaves — chewed milkweed is the goal.