Monarchs and Milkweed

In Conservatoryby Cambridge Butterfly Conservatory

The Ontario Monarchs are off! They’ve felt the environmental cues – colder weather, shorter days, and fewer milkweed plants – and they’ve packed their bags and headed south. They have a two-month, 4000+ kilometer journey ahead of them before they arrive in the Sierra Madre Mountain range in Central Mexico where they will spend the winter.

After their long hibernation, these same Monarchs will fly north and lay eggs on the closest milkweed they can find, located in Texas. Their offspring will be able to fly a little bit more north to lay more eggs, and the next generation will head even more north, and so begins the two-week sprint of each generation making its way back to Canada via a relay race method.

Though we won’t see Monarchs back in Ontario until late May/early June, now is actually the perfect time to take action and help next year’s butterflies. By now you’ve likely heard that to help this Species at Risk, the best thing we can do is plant milkweed in our gardens.

We can start our preparations now buy harvesting milkweed seeds. When the autumn chill hits, milkweed seedpods dry out and crack open, releasing parachute seeds like a dandelion. These seeds require cold stratification, meaning they need a cold period before they will sprout. Planting the seeds now means that the winter will do this naturally and they will germinate beautifully in the spring. Just sow the seeds in a sunny site and cover with soil.

Don’t worry if you forget to plant them and you are sitting with a jar of dry seeds next spring! You can easily trick milkweed seeds into thinking they went through a winter period by storing them in the freezer for a few weeks before planting them. So as you wave goodbye to those Migratory Monarchs, be on the lookout for those wonderful milkweed pods!