I already have a number of butterfly-friendly perennials in my garden, including purple coneflower, liatris, and monarda. And the fields bordering my yard are filled with wild asters and goldenrod, which provide abundant nectar in autumn. However, while these are good sources of nectar for butterflies, they don't provide food for the larvae. While gardeners most enjoy the colorful adults, the reality is that most of the insect's life cycle is spent in the form of a caterpillar. So while planning your butterfly garden, be sure to include host plants such as ornamental milkweeds and parsley.
Scientists believe that seasonal changes in day length and temperature trigger the urge to migrate.
Butterflies that emerge in early autumn here in New England immediately begin preparing for their long journey by feeding on nectar. To provide a healthy habitat for butterflies, avoid using pesticides, especially when butterflies are active. But most plants can tolerate some damage from caterpillar feeding, so pest control is rarely warranted. Even organic pesticides can be hazardous to butterflies. I occasionally use Bt , a biological control, to manage cabbage loopers and cabbageworms on my cole crops.