Phone: 508.255.5716
Send us an email

Mailing Address
P.O. Box 183
Eastham, MA 02642

Eastern Monarch Butterfly Population Falls Again

Although 2021 was a good year for monarch butterflies in the Northeast, the Eastern population (east of the Rockies) continues to show a dramatic decline. Population assessments are made each year based upon the area covered by the overwintering butterflies in Mexico. The population in 2021 showed a 26% decline over the prior year and 80% decline over the past two decades. Monarchs are threatened by pesticides, climate change, and loss of habitat (aka milkweed). Monarchs have lost an estimated 165 million acres of breeding habitat in the U.S. in recent decades due mostly to herbicide spraying ‘Roundup’ and development. For many years there has been talk about listing the Monarch as an endangered species and FINALLY this designation was made official on 21 July 2022.  The Monarch is now included on the IUCN Red list of Threatened Species as Endangered.

So, what can we do? Answer: plant native milkweed! This is the plant that the monarch butterflies are totally dependent upon for reproduction. In the Northeast there are three kinds of milkweed: common (Asclepias syriaca), swamp (A. incarnata), and butterfly milkweed (A. tuberosa). Generally, the common milkweed is more suitable for large areas. The swamp and butterfly milkweed plants are more suitable for home gardens because of their beauty and ease in controlling propagation. Even just a few plants in a garden can make a difference and both are available at local nurseries. ECF has planted both species in pots from seed and if successful, will be available for free in late May.