Butterfly host plants:

Planting butterfly host plants is a great way to attract butterflies. The females spend a longer amount of time on host plants than on nectar plants and even if you do not see the butterfly, you will be surprised how often a caterpillar appears on the plants. Butterflies have a high biotic potential in that they lay many eggs, but do not be surprised if you see all the caterpillars get eaten. Even though caterpillars use aposematic colouration, batesian mimicry, camouflage and concealment, survival rates around 5% or less are common. Children love looking at caterpillars and if you want to increase your chances of finding them in your garden, plant host plants for common butterflies such as monarchs, black swallowtails or american painted ladies.

A black swallowtail when threatened exposes its osmeterium, which is a defensive organ that gives off a foul smell to deter other invertebrates. This forked structure is possessed by all swallowtails.

This plant list includes butterflies that could be expected to be found in Southern Ontario (and therefore the surrounding areas in north eastern part of N. America). The list does not include butterflies restricted to holoarctic areas further North. Some of the plants on this list are highly unsuitable for gardens (such as Laportea, which have leaves that sting) or are exotic to Canada. Before attempting to grow any of these plants, make sure that they fit the ecology of your local area.

The banded woolly bear caterpillar is the larva of the moth Pyrrharctia isabella. It feeds on a wide range of hostplants so you are quite likely to see this caterpillar in your garden. It will overwinter in the garden as a frozen caterpillar and pupate in the spring.

By butterfly: