Released in February, the annual report on overwintering monarchs in Mexico indicated a significant drop in the population (59%!!). This was attributed to drought conditions (which can reduce available host and nectar plants) along their migration path from Oklahoma into Mexico. [Read more here.]
The Monarch Migration
Monarchs have multiple generations during a year. In the US, there are two primary “groups” of monarchs – one west of the Rocky Mountains and one east. The western population overwinters in trees along the California coast and the eastern group heads primarily to the mountains of Central Mexico.
In spring, the eastern monarchs head north and breed in the southern part of the United States. The resulting generation then continues northward and repeats the cycle, with the butterflies eventually reaching our area and into southern Canada. There can be three to five generations during the overall season before the last group emerges in late summer and fuels up to head south again.
Supporting Monarchs
The population can bounce back! We can help by adding plants to our gardens that support the monarchs and other pollinators.
Some pollinators have specific host plants that they rely on. Host plants are what adult butterflies lay eggs on and the caterpillars feed on. For monarchs there is only one host plant: the milkweed family (asclepias).
Once the caterpillars mature into adults, they need a different type of food. When it comes to food sources (nectar plants), there are lots of options! I notice they are most drawn to open-faced flowers where it is easy to land and access the nectar, like zinnias and cosmos. Try to plant a variety of things, in groups, to offer a diversity of nutrients.
Nectar plants, organized by bloom season, are listed here.
The plants in bold are “preferred” suggestions. The “NE” column is for New England, and “MA” is for Mid-Atlantic, with sub-columns for Inland (IN) and Coastal (C) areas.
Don’t Forget a Drink!
With your host plants and food plants, it’s great if you can also provide a water source. Though I see butterflies and bees visiting my water feature, even just a “puddle” will work. I use a large glazed plant saucer with some stones and pebbles for landing spots. Something shallow that can dry out every few days will minimize the presence of mosquitos; just remember to give it a refill.
More Pollinator Posts
For more on pollinators and other beneficial insects, revisit these posts:
Pollinator Week 2023 (Who are the pollinators and what threats are they facing?)
Pollinator Habitat (Pollinator needs, selecting plans, and providing shelter)