Are Monarch butterflies really disappearing as a species?

Published 11:30 am Sunday, July 31, 2022

Are Monarch butterflies, one of the most visible poster insects of earnest home garden environmentalists, really disappearing as a species?

These large, orange-and-black creatures, which migrate through successive generations from their overwintering site in Mexico to as far north as New England and Canada, were recently listed as an “endangered species” by a prominent international science group. But it turns out, this may not be the headline-grabbing bad news it appears to be.

In spite of the huge decline over the past three decades caused by habitat loss and the widespread, increased agricultural use of herbicides killing the flowers that both adult Monarchs and their larvae depend on, all of the recent data about monarchs has painted a positive picture.

I’ve nearly gone blind sifting through dozens of official butterfly publications and science blogs written by hard-core butterfly researchers with their voluminous data collected over the past 30 years and more. And, as my wont, I’ve crunched scientific jargon into garden-variety language.

Bottom line seems to be that contrary to popular belief based on alarmist headlines of news articles citing outdated or misleading information, Monarch butterflies are not in danger of extinction. In fact, across North America they have increased substantially in numbers over the past several years. So, what’s up?

Turns out, most of the alarm is based on dwindling numbers reaching the overwinter sites in Mexico and California. There are all sorts of debates on the underlying causes, so, to ease my mind, I dug in deep. Really deep.

For several reasons “big picture” reasons (beyond gardeners’ control), adult Monarchs headed to their frost-free winter homes have taken a hit. Efforts to change this are gaining traction, mostly with habitat protection in Mexico and refuges planted along our southern borders.

However, the winter losses don’t actually affect their booming reproduction rate once they make it back to the States; the latest data show that they are actually increasing in numbers and range. Other words, in the summer they are making more new butterflies than ever.

Want to invest garden space, time, effort, and money saving monarchs? Easy: Plant a big, easily-visible flowerbed or border full of pollinator-friendly flowers that bloom over a long time, period. Adult monarchs don’t actually feed as much on milkweed flowers as they do many other plants, including natives like Liatris, coneflowers, and asters of all types (including goldenrod), plus dependable nonnatives such as zinnias, lantana, salvia, and others that attract butterflies and bees in general.

Because Monarch butterflies lay eggs only on milkweed plants (Asclepias species), include some of those for their larvae, but don’t stress over this – there are plenty of milkweeds around our woodland edges, riverbanks, fencerows, and infrequently-mowed ditches. Really.

What about the tropical milkweed plant being sold by the thousands in garden centers? True, it can host a microscopic parasite that weakens Monarchs somewhat; however, this is blown way out of proportion, just like how nandina berries supposedly are killing all our birds (they aren’t). This isn’t a garden scale problem; the concern is mostly along the Gulf Coast and Southwest Texas where the Mexican native plant spreads by seed and doesn’t die down in the winter. Just cut yours down in the fall.

Don’t let shrill purists beat you up for planting tropical milkweed, which is a stunning garden plant, flowers nonstop, and hosts Monarch larvae. A few tropical milkweed plants in your garden are just fine and won’t slow down the overall Monarch boom.

Monarchs are doing better than many other butterfly species. Help one by helping them all, by planting long-blooming flowers. Of all types.

Felder Rushing is a Mississippi author, columnist, and host of the “Gestalt Gardener” on MPB Think Radio. Email gardening questions to rushingfelder@yahoo.com.