When we moved into our home in Georgetown, MA about 18 years ago, we had about 2 weeks each fall when we would see upwards of 30+ Monarch butterflies a day flitting through our yard. They were en route to the mountains in central Mexico over winter before returning back to this area and further north the following spring. Now I see about 6 total all season! One of the biggest reasons for that is GMO agricultural seeds. Farmers are now planting seeds that have been modified to be able to resist RoundUpR, and can then spray entire fields with RoundUpR to kill any broadleaf weeds or grasses that are not their desired crops. Unfortunately, this practice has helped to decimate the common milkweed, Asclepias syriaca, which grew on the sunny borders of these agricultural fields and along roadways. By taking away a major food source, it makes this 3000 mile journey much more difficult for the Monarchs to complete.
Asclepias syriaca, is the main food source for the Monarch caterpillars. So in order to save the Monarchs, I encourage folks to harness their inner child, find some native milkweed pods, let them dry until they start to break open, then take them to a wild area near your home…remember how much fun it is to blow the fluff from the seed pods and spread the seeds! Alternatively, if you cannot find any common milkweed, you can order seeds for your own Butterfly Garden from monarchwatch.org. They have kits that have a variety of food sources for adult butterflies and the Asclepius for the caterpillars.
Just a quick word of caution, Asclepius syriaca does spread by rhizomes, so if you like neat and tidy gardens, you may not want them in your formal gardens because they will pop up in unexpected places. That being said, if you would like to have a dedicated ‘butterfly garden’ to be able to observe the caterpillars, chrysalis and butterflies up close, it’s a perfect plant choice. I have seen caterpillars on parsley and dill as well, but they much prefer the tender leaves of the milkweed. One of the articles I read for this blog suggests cutting back about half of your large milkweed stems to the ground in June-July, to allow tender shoots to regenerate making more attractive sites for the ovipositors to lay their eggs. This will allow you an up close view of the cycle of the Monarch.