What plants can I put in the garden at home to attract butterflies?
To attract butterflies to your yard, you need to provide the two things they are looking for: a source of nectar and, for the females, the appropriate host plant on which to lay eggs.
The best nectar plants are those that also serve as a host plant for butterflies–milkweed comes to mind as a good nectar plant that is also a host plant for the monarch butterfly. Unfortunately, there are not many plants that do this sort of double-duty. Many good native nectar plants do not host a local butterfly species, but they do host moths and other insects and thus play an important role in the ecosystem.
For example, goldenrod is an excellent nectar plant. While it doesn’t host any butterflies, hundreds of native insects feed on it, which in turn provide food for birds and other wildlife. Asters (several species) also provide a good late-season source of nectar. Early nectar sources include cherry, apple and crabapple trees. A closely related species that is also native is shadbush (= serviceberry, saskatoon). Wild bergamot, bee balm and blazing star are gorgeous mid-season nectar plants.
Butterflies will also use rotting fruit as a source of sugar. The mourning cloak butterfly, which is one of the earliest species to be seen in spring, feed on tree sap, and can often be seen feeding from the holes made by yellow-bellied sapsuckers.
The host plants that serve as food for the caterpillars of Ontario butterflies are not necessarily beautiful flowering plants that you would typically see in a garden. Here are some of my favourites:
- Stinging nettle: attracts red admirals and comma butterflies, in huge numbers in some years
- Thistles: attract the painted lady butterfly (avoid the so-called Canada thistle, which is not Canadian, and which is an invasive spreader. Go with bull thistle instead.)
- Hop tree and prickly ash: for the giant swallowtail
- Dill and fennel: for black swallowtails
- Hackberry: question mark butterfly
- White turtlehead: Baltimore checkerspot
- Chokecherry: tiger swallowtail