Planting for Monarch Butterflies: A Guide for the Northeast Gardener
Monarch butterflies are one of North America’s most iconic pollinators. They’re famous not only for their brilliant orange-and-black wings but also for an epic migration that spans thousands of miles. Unfortunately, monarch numbers have dropped over recent decades. As a Northeast gardener, you can help these amazing creatures by planting the right flowers and creating safe habitats. Let’s explore how monarchs live their lives—and how you can support every stage of their journey.
The Monarch’s Incredible Journey
Monarch butterflies have a unique migration unlike any other insect in North America. They travel up to 3,000 miles (that's about 50-100 miles a day!) between their breeding grounds in the United States and Canada and their overwintering sites in the mountains of central México where they cluster onto Oyamel Fir trees to keep one another warm. Side note - Google images of ‘Monarchs in Michoacán México’ and prepare to be in awe.
Here’s how the Monarch migration happens:
Spring Migration (1st Generation) Each March, monarchs that spent the winter in central México begin flying north. They lay eggs on milkweed plants in the southern United States before dying.
Late Spring and Summer (2nd & 3rd Generation)
The butterflies that hatch from those eggs continue flying north, breeding and laying eggs as they go. This process repeats through two or more generations. In the Northeast, monarchs usually arrive between late May and July. These summer generations live about 2–6 weeks each.
Late Summer and Fall (4th Generation - The Super Generation)
The final generation is special. Unlike their parents and grandparents, these butterflies delay reproduction and live up to 8 months. They migrate all the way back to central México, sometimes covering more than 2,000 miles, where they cluster by the millions on Oyamel Fir trees to survive the winter.
Come spring, the cycle begins again!
Milkweed: The Essential Host Plant
Monarch caterpillars only eat milkweed (Asclepias species). Without milkweed, monarchs cannot reproduce because caterpillars will have no food. Adult butterflies lay eggs exclusively on milkweed leaves so that tiny caterpillars can start feeding as soon as they hatch.
Recommended milkweed species for the Northeast:
- Common Milkweed (Asclepias syriaca) – Tall and fragrant, though it can spread vigorously.
- Swamp Milkweed (Asclepias incarnata) – Prefers moist soil, less aggressive spread.
- Butterfly Weed (Asclepias tuberosa) – Brilliant orange blooms, ideal for drier soils.
⚠️ Important Note on Milkweed and Livestock:
Milkweed contains cardiac glycosides, which are toxic to livestock and farm animals if eaten. If you have horses, cattle, goats, or sheep, plant milkweed in dedicated beds or enclosed gardens well away from pastures.
Nectar Plants for Adult Monarchs
While caterpillars depend entirely on milkweed, adult monarchs need nectar from many different flowers to fuel their long journeys. A mix of native, nectar-rich plants will support monarchs from spring through fall.
Excellent nectar plants for Northeast gardens include:
- Joe-Pye Weed (Eutrochium spp.) – Tall, statuesque with large pink flower clusters. Leonie thinks they smell like honey!
- New England Aster (Symphyotrichum novae-angliae) – Late-season purple blooms for migrating monarchs.
- Goldenrod (Solidago spp.) – Golden rods that dance in the wind provide fall nectar source.
- Bee Balm & Wild Bergamot (Monarda) — Bright red, pink, or lavender blooms that attract butterflies and hummingbirds.
- Black-eyed Susan (Rudbeckia hirta) – Bright yellow flowers that bloom for long periods.
- Coneflowers (Echinacea spp.) — Sturdy, wide blooms perfect for butterflies to perch while feeding.
- Zinnias (Non-native) — Easy annual with bold colors and flat blooms that make great butterfly landing pads.
Planting a variety of nectar plants ensures monarchs find food no matter when they pass through your garden, providing them with enough fuel to continue their journey south.
Shelter and Habitat
Beyond food, monarchs need shelter from wind and predators. Clump plantings, tall grasses, and native shrubs offer resting spots. Remember not to use any pesticides in your native or pollinator gardens. The whole point is to create a safe habitat for beneficial insects like monarchs—not to destroy them or their homes.
Yes, some of your plants will look a bit chewed up—but that’s a good thing! It means caterpillars are thriving. If you’d prefer to keep the rest of your landscaping untouched, you can always create a designated native or pollinator garden separate from your other beds.
Help Monarchs on Their Epic Voyage
By allowing milkweed to grow for caterpillars and plenty of nectar flowers for adult butterflies, we can create vital stepping stones for monarchs as they journey across the continent.
With thoughtful plantings, you’ll enjoy the beauty of monarchs fluttering through your garden and play a crucial role in preserving one of nature’s greatest migrations.