May Native Plant of the Month

Native Florida milkweed is blooming now and will continue through the end of summer before going dormant for winter. This dormancy stage is necessary for healthy migratory patterns of monarch butterflies. Milkweed is a necessary host for the survival of monarch butterflies as the sole host plant for their caterpillars.

There are several varieties of milkweed native to Florida and all are host plants for monarch caterpillars as well as queen and soldier butterflies. They are also a favored nectar source for other pollinators including bees and wasps.

It is important to always consider the source when purchasing milkweed plants. Common native varieties found in nurseries include A. incarnata and A. tuberosa with the latter being more common. Unfortunately, it is easy for some to mistake for tropical milkweed which should not be planted in Florida.

Note the differences in this image from Xerces:

Tropical Milkweed A. tuberosa

Unlike native milkweeds, tropical milkweed does not go dormant in winter, interrupting the natural migrating behaviors of monarch butterflies. While some enthusiasts will suggest simply trimming the tropical plants back in winter to encourage migration, this may not properly address another problem with the plants, disease. The longer growing season allows a parasite, Ophryocystis elektroscirrha, to accumalate more spores on the plants, leaving a toxic meal for larval monarchs.

Another issue to be aware of is that best intentions don't always mean best practice. Many nurseries are trying to offer native plants as demand increases. But if the nursery is not dedicated to native plants or propagating their own plants, the plants may have been sprayed prior to shipment or even as regular maintenance. Always check and if there is any doubt, better to search for a better plant source as pesticides are another major threat to monarch survival. It's also possible to find seeds and grow your own.

Ultimately, milkweed is a stunning addition to the landscape, but care must be used when purchaing and planting.