January 2024 Milkweed Issues

As mentioned in our short article in this month’s newsletter there are some issues with growing tropical milkweed (Asclepias curassavica) in our area. If your main goal is to help the monarch butterfly – then do not grow tropical milkweed! There are some caveats to this statement which I will mention below.

The first thing we must understand is that tropical milkweed is a non-native milkweed which may grow throughout the year in our growing zone, depending on how severe a frost we may have.

The picture above shows milkweed doing quite well, putting out new flowers and growth. Granted the stems are getting ‘bare’ but they are about five-six feet tall and doing well in November.

Herein is the problem! Assuming we will not get a killing frost this milkweed will not dieback during the winter. As mentioned in the newsletter article the monarch may have OE (Ophryocystis elektroscirrha) which is a protozoan parasite. These spores are harbored on their outside of the monarch and are spread on the milkweed plant as the monarch crawls about. This enables the spores to infect any other monarch thereby spreading OE. If the monarch has a severe infection, it can have deformed wings, may not emerge from their pupae stage, cannot fly, and may not make their annual migration to Mexico where they would normally reproduce.

Possible solutions to this issue are to plant native milkweed species such as A tuberosa (butterfly weed), swamp milkweed, purple milkweed, and other plant species such as zinnias, sunflowers, black-eyed Susan, and other perennials. See last month’s article on where to get native milkweed seeds.

Another solution, if you absolutely must have tropical milkweed, is to cut your lush, beautifully flowering tropical milkweed back to the ground a couple of times during the year then remove the plants in late summer or early fall and start over next year.

So, the point is that all is not lost if you want tropical milkweed BUT you must be careful to protect our monarch butterflies! I will be pulling my tropical milkweed up in the next couple of weeks and putting them on a burn pile to get rid of them and start over next year – I’m sorry but I do like my tropical milkweed.