Conservation: Monarchs and Milkweed

By Houston Sneed, Plant Conservation Officer

Across the planet, plants and animals have formed close relationships with each other. One beautiful example of these relationships, monarch butterflies and milkweed (Asclepias species), can be found right here in our Northeast Florida landscape. Monarchs depend on milkweed, where they lay their eggs, and when they are caterpillars milkweed is the only food they can eat.

Unfortunately, as humans develop land across the range of monarch butterflies, milkweed is disappearing in these agricultural, urban and suburban landscapes. Another problem is the ornamental use of a nonnative Mexican milkweed (Asclepias curassavica), which does not go dormant. By continuing to grow in the winter, this tropical milkweed keeps some monarchs from starting their fall migration in time to make it to Mexico where they spend the colder months. This nonnative milkweed also promotes the spread of a deadly parasite commonly known as OE (Ophryocystis elektroscirrha). With a reduction in the amount of native milkweed across their range, and pests like OE, monarch populations have alarmingly become much smaller than they were in the recent past.

This spring, we aim to grow tens of thousands of native milkweeds for planting around the retention ponds in the parking lot. The main species we will be growing this year is swamp milkweed (Asclepias incarnata), a highly ornamental variety that we hope to see flowering later in the year. Not only is this a native species of milkweed, but all the seed was collected locally, which will produce plants better adapted to Northeast Florida’s climate. This planting will not only increase the amount of monarch habitat in our area, but moving forward, will also produce seeds that we hope to share with community partners, members and the public.

“…when they are caterpillars milkweed is the only food they can eat.”

The yellow object is a Monarch egg.

Monarch caterpillar.

Monarch chrysalis.

Monarch Butterfly