monarch-caterpillars-butterfly-exhibit SF

Monarch butterflies. [H. Guenther]

I recently participated in a twitter event on #gardenchat* about Monarch butterflies. At the end of the session the question,“Does your website have a blogpost about butterflies?” was asked. I was shocked to realize that I not written one! I decided to rectify my lack of a butterfly post and in the future I plan to write about pipevine swallowtails, red admirals, anise swallowtails and skippers.

Why are Monarchs Amazing?

Each year, monarchs migrate thousands of miles. However, only one generation out of five generations completes this long journey! This generation overwinters in Mexico, then, in early spring,they fly to the southern part of the U.S. where they mate and lay eggs on milkweed plants. The eggs hatch and grow to become the first generation that mate, fly further north, and lay eggs. This continues for four generations during spring and into summer, with each generation living about 5-8 weeks.


Monarch caterpillar.

In summer, the 4th generation of monarch butterflies reaches their destination in the northern United States and Canada. In late summer, the fifth generation of butterflies is born, and these butterflies are the generation that make the the long journey back to Mexico.

Monarch Life Cycle


Monarch chrysalis is perfectly camouflaged on milkweed.

Monarch eggs hatch after about four days. The small caterpillars eat large amounts of milkweed and go through five developmental stages until they get big enough to form a chrysalis and go through metamorphosis.

The process of metamorphosis is a dramatic change when a crawling caterpillar transforms into an aerodynamic butterfly. This all happens inside a chrysalis. The body of the caterpillar actually liquifies to complete this change. I really can’t think of anything else in nature that is as mind-blowing as metamorphosis, can you?

Myths about Monarchs

Many people think birds don’t eat monarchs because they are poisonous. It’s true that monarchs are distasteful to birds and give them a stomach ache, but birds find this out by tasting and/or eating them.

How Can you Help Monarchs?

Monarch butterflies need several things to survive. A food source for caterpillars, shelter for adults, water and nectar. Provide this in your garden by planting various types of milkweed in large patches for caterpillars. Create places with shade and small amounts of water. Plant a variety of plants that flower at different times so the adults have a steady food supply.

Avoid using pesticides in your garden. Pesticides that harm butterflies include Bt or Bacillus thuringiensis. Although Bt is an organic, naturally occurring bacteria, it gives any caterpillar a deathly stomach ache.

Grow milkweed plants to give to friends and tell them how to attract and protect monarch butterflies. In 2016, a scientific study came out that determined it is highly probable that this amazing species could go extinct in the next 20 years. That would be a terrible shame. I hope you’ll join me in supporting and protecting this gorgeous natural wonder of our world.

*#gardenchat is run by Bren Haas @GardenChat. Join this friendly group on twitter Mondays at 9-10 ET!