Planting Monarch butterfly habitat meadows is futile if they’re not managed properly. Mowing at the wrong time can kill monarch adults and/or destroy eggs, larvae and pupae. When is the best time to mow? In a few words, when Monarchs aren’t present. These abbreviated recommendations are from Monarch Joint Venture:
1. Avoid mowing the entire habitat to leave refuge areas for wildlife during mowing. This will allow for recolonization of the mown site. Leave areas that may be good nesting or overwintering sites (leaf litter, dead stems or other groundcover) for pollinators or other wildlife.
2. Timing of mowing is critical (see map). Avoid mowing during times of peak insect activity; this timing will vary between species. If your goal is Monarch habitat, don’t mow during times of high Monarch reproduction or migration. Some areas may benefit from summer management to promote fall milkweed growth (and thus, Monarch reproduction). For instance, the southern Great Plains where Monarch activity is low for an extended period of the summer.
3. If possible, avoid mowing while native plants are in bloom or before they’ve dispersed seed.
4. Limit mowing to no more than twice per year and even less if possible. Mowing too frequently disrupts plant growth and the ability of forbs to compete with grass species. However, during the first year of prairie restoration, more frequent mowing may be needed for weed control.
5. Use a flushing bar and cut at reduced speeds to allow wildlife to escape prior to mowing.
6. Cut high, using a minimum cutting height of 8 to 12 in. (shorter heights may be needed for early establishment mowing).
7. Avoid mowing at night, when insects are inactive and unable to escape.
Mowing: Best practices for Monarchs, a two-page PDF file with these recommendations and more.
NewTerrain February 15, 2016