A Gardener’s Homegrown Field Study
- jsrhollis
- Oct 16
- 3 min read
By Linda Ray
On my little piece of paradise there are two large sections of the yard dedicated to common milkweed (Asplepias syriaca) which has been proliferating for years. Common milkweed and swamp milkweed (Asplepias incarnata) have been shown to be preferred by monarchs as host plants.
These two types of milkweeds average the highest number of eggs (among species of milkweed) in field testing.
What a resource my large patches offer monarchs and other pollinators! The milkweed blossoms bloom by mid-June. The heavenly aroma and ample amounts of nectar are a call to insects to come and feast and/or lay eggs or both. The monarch butterfly doesn’t start to make an appearance here until the last weeks of July. By this time the milkweed blossoms are wilted, and their leaves are already starting to degenerate. The larger group of later- arriving monarchs have a less than perfect option for egg laying come mid-August. Over the years it has become clear the timing is just off.
Habitat management studies have indicated that mowing milkweed to extend new growth has been shown to help monarchs. Young green leaves are very attractive for egg laying, and regrowth seems to attract fewer predators as well. Careful planning is necessary so that pollinator habitats are not destroyed with dense mowing, mowing is timed to the monarchs’ schedule, and pollinator refuge areas are maintained. Research outcomes suggest that pruning 6 to 8 inches of the milkweed in mid-July results in the greatest number of eggs and caterpillars on new leaves in later summer.
I decided to conduct my own homegrown field study to observe this outcome for myself. I had a very concrete goal. If I divided one large patch of milkweed into three sections with different pruning schedules, would one section stand out by exhibiting more green leaves in mid to late August? We are not talking rocket science here, but every week each section was assessed, notes made, new leaf growth documented and many pictures taken. Even within this simple plan, amateur oversights and unanticipated acts of nature occurred.
It could not be predicted that there would be a drought in Maine this summer. The drought-stressed plants became vulnerable to aphids which led to honeydew plastering the milkweed leaves. Honeydew is a sticky residue left by the aphids which can result in a moldy growth. Monarchs do not find those conditions attractive for laying eggs. By the first week of September there were no green leaves on any section of the milkweed testing spots. Was it lack of water, aphids, or both that impacted this testing scenario? So much for any concrete outcomes.
As gardeners know, there are always successes and failures every growing season. We learn what will or will not thrive the hard way and take our lessons into the next growing season. I don’t think I did any harm except for assuming that I knew what I was doing. Having learned more about what can be controlled, I will cross my fingers and repeat a modified version of this next year with much more knowledge and appropriate expectations.
Sources:
Comments