This one requires close parent supervision and at least a 2- to 3-week commitment. If you’re prepared for that, read on!
This activity is inspired by a friend who planted her garden full of Common Milkweed (the kind with the pom pom blossoms) to give Monarch butterflies a boost and then watched in horror as egg colonies and caterpillars were devoured by wasps, lady bugs, mice, ants….
It’s actually quite easily – and absolutely rhapsodizing – to create a Monarch nursery. My 3rd grader and his grandfather have released over 20 butterflies since starting a few weeks ago.
First, you’ll need lots of native milkweed. The native part is crucial (tropical milkweed increases the risk of disease and confuses the Monarch migration schedule). For our 20 butterflies, we needed 6 potted milkweed plants to rotate through the nursery – and some additional milkweed plants in the garden from which to collect the caterpillars.
You’ll need one or 2 net cages – ours cost $10 each. We started with one and quickly found we needed a second. We used one as the “infant room” for the smaller caterpillars – which we transferred to the “delivery ward” when they had become big and fat and ready to build a chrysalis. That allowed us to keep the smaller ones safe and the chrysalises undisturbed.
We placed a milkweed pot in each cage and rotated them out as the hungry caterpillars stripped them. We also added a tall sage plant to the delivery ward for the caterpillars to build their chrysalises on (they avoid hanging from milkweed for fear that their leaf will be severed by a hungry caterpillar). When the cage becomes littered with caterpillar droppings, be sure to clean it out and start fresh to avoid disease.
Most of our caterpillars became healthy butterflies, but there were a handful that were much darker than the rest of caterpillars which we separated from the rest of the group. We noticed that when these made chrysalises, instead of the apple green housing, theirs had brown spots on them. They never developed into butterflies. If you notice anything peculiar, be sure to isolate the caterpillar or chrysalis as disease can be easily transmitted.
You’ll see your healthy caterpillars cling to the side of the cage for a day now and then – they do this when they molt, or shed their skin. It’s important not to disturb that process. After a few molts, when they are big and plump, they’ll find a spot on the ceiling of the cage – or the underside of a leaf of the plant you stuck inside the cage with them. This is where it gets truly riveting. After a day or 2 of hanging upsidedown in a “J,” you’ll see them pulse and wiggle a bit – and then, within minutes, their skin splits at the bottom, revealing a bright green shell. Within 5 minutes, the skin is shed and all that remains is a gold-rimmed, fresh green chrysalis.
After 5 to 10 days, the chrysalis will turn dark green – and then as it becomes more and more transparent – and darker and darker – you’ll be able to see that pattern of the wings through the wall of the chrysalis. Once that happens, the butterfly will emerge within hours. Ours have all favored late morning – but a friend who has just started her own nursery says her butterflies have all emerged after midnight.
This is an indescribably gratifying project – from which you and your child will learn so much – and because of which the Monarch population will grow!