Some people watch for robins patrolling the lawn. Others wait for the first sign of cherry blossoms. But for some people, spring hasn’t arrived until they see their first butterfly, colorful wings flashing in the sun. Perhaps you’ve already seen your first butterfly this year, or maybe you’re still anxiously awaiting its arrival. Here are a few things to remember about springtime butterflies and butterfly gardening.
What happens to butterflies in winter?
The answer to this question varies by species. A few species migrate or move further south, like the famous Monarch migration. But most butterflies overwinter in the same area where they spend the summer, in various forms. Some butterflies, like the Mourning Cloak, overwinter as butterflies without migrating (though some populations will head south for the winter). These butterflies seek out dry cracks in the rocks or warm tree hollows and hunker down for winter. Other butterflies, like Great Spangled Fritillaries, overwinter as caterpillars buried in the earth. And some, like Cabbage White butterflies, overwinter in chrysalis (pupa). In all cases, these creatures enter a state known as “diapause“, which is much like hibernation, in which all of their bodily functions stop until the weather warms up again. (Learn more about butterflies in winter here.)
How warm must it be for butterflies to fly?
Butterflies are “poikilotherms”, which is essentially like being cold-blooded; their body temperatures reflect the temperatures outdoors. Most butterflies need a body temperature of about 80 degrees F to fly, but it doesn’t need to be nearly that warm outside. Butterflies use solar energy to pump up their body temperature by as much as 20 degrees above the temperatures outside. So when outdoor temperatures consistently start reaching 60 degrees F or so, butterflies will begin flying, at least on sunny days.
Which butterflies appear first in spring?
This of course varies by region, but here are a few to look for as soon as days hit the 60s and 70s in your area:
- Mourning Cloaks (Nymphalis antiopa) overwinter as butterflies, and will emerge as soon as the days warm up, probably looking a little tattered and worn. They can be seen across most of the country.
- Eastern Commas (Polygonia comma) also overwinter as adult butterflies, emerging in early spring and laying eggs on the first new growth of nettles and elm trees. As the name suggests, they’re found in the eastern half of the country, except the Deep South.
- Cabbage Whites (Pieris rapae) and other members of this genus overwinter in chrysalis, making their appearance in early spring as newly-emerged butterflies. They’re seen around the country, and their caterpillars are often considered pests by vegetable farmers. (Learn more here.)
- Spring Azures (Celstrina ladon) are another butterfly species that overwinter in chrysalis and appear in early spring as newly-emerged adults. This tiny blue butterfly is found throughout the country, except in the Deep South.
What if butterflies emerge before there any plants for them to nectar on?
The “first” butterfly of spring, the Mourning Cloak, has this problem solved. It actually rarely nectars on flowers, instead preferring tree sap, which by now has been running for weeks in most places. In other cases, the earliest wildflowers of spring coincide with the first butterflies, and some of the best early nectar plants are actually flowering trees like redbuds and dogwood.
How do I attract early butterflies to my yard?
The earliest butterflies may not visit flowers as often, but they’ll still need the right host plants to lay their eggs. Find out which butterflies visit your area in early spring, and make their host plants a part of your butterfly gardening efforts. Provide a few large flat rocks in your butterfly garden, too, for butterflies to bask in the sun on cooler days, and some native ornamental grasses or shrubs for them to seek shelter when spring rains pop up. Get good nectar plants started early, so your garden will be full and inviting when more butterflies arrive. It’s also not uncommon for some butterfly species to visit hummingbird feeders when plant nectar is scarce, so fill your hummingbird feeders when butterflies start to appear to see if you can lure in a few extra visitors.
Have more questions about butterflies? Drop by our Community forums to send me your questions. Have you seen your first butterfly yet? Share your sightings with others here!