We often think and talk about environmental work in distinct sections, such as protecting water quality, improving habitat for certain species, removing invasives, or planting natives. Those who work or volunteer in the environmental sector understand all components of environmental work intersect and working in one area can affect another part of the environment. However, the greater public doesn’t always consider those connections.
The Monarch Joint Venture Project explored the important connections and mutual benefits gained between native plants, monarch habitat, and water quality protection in a recent article:
You may be asking yourself, how can monarch conservation help improve water quality and reduce the likelihood of flooding events? The answer is that any monarch planting, large or small, helps reconnect and restore some of the natural functions that our landscape historically provided. Because of this, the habitat you plant to help monarchs can make a positive impact on the water quality in your watershed. Whether you are a gardener, land manager, farmer, city planner, or another type of land or water steward, your pollinator habitat project can make a difference.
Unlike turf grass, native plants that make up monarch and pollinator habitat like milkweed, wildflowers, and bunch grasses, have deep root systems that can reach several feet into the ground. These roots not only provide soil stability and prevent erosion, they also form channels in the soil that help rainfall soak in and replenish our groundwater supply. Moreover, some plants act as sponges for heavy metals and other pollutants, and can prevent them from getting into our streams, rivers, and lakes by soaking them up into their tissues with the water and removing them from the soil. Native plant buffers along roadsides, streams, and agricultural fields, residential or corporate rain-gardens, and any other type of landscaping can be planted with native milkweed, wildflowers, and grasses. These plants provide food and shelter for many wildlife species, including monarchs, while also helping to slow the flow of runoff and prevent contaminants from reaching our waterways.
Planting habitat for monarchs actively reduces the amount of runoff and pollution in our waterways by disrupting the flow of runoff and providing additional places for water to go in the ground. It also requires fewer inputs than other ecosystems, like crops, lawns, or ornamental landscaping. Native flowers and grasses existed long before European settlement alongside the other flora and fauna, and are well adapted to regional soil and moisture conditions.
Be Careful choosing your milkweed!
The drive to promote monarchs and their habitat has largely been in response to the nearly 90% decline in the monarch populations since the mid-1990s. One main message was to plant any and all milkweed. Unfortunately, there have been some unintended and unexpected consequences from the implementing that message. As the Arkansas Natural Heritage Commission explained:
The species of milkweed most commonly available to plant in the United States is tropical milkweed (Asclepias curassavica), which is not native to North America. It turns out that tropical milkweed doesn’t die back in the winter like native milkweed does, creating new winter breeding sites, keeping monarchs from migrating farther south. Although that might not sound like such a bad thing, it poses a great threat to monarchs – it hosts a parasite called Ophryocystis elektroscirrha (OE). Monarch caterpillars ingest the parasite while feeding on milkweed and then emerge from their chrysalises covered in OE spores. Infected monarchs are weakened by OE and don’t live as long, and an OE-infected monarch that tries to migrate will probably die before it reaches the overwintering sites in Mexico.
A study reported by the Proceedings of the Royal Society B. concluded that monarchs who stayed in the southern United States for the winter were five to nine times more likely to be infected with OE than migrating butterflies.
Plant Native Milkweed!
Plant only native varieties of milkweed. In Arkansas, that includes curly milkweed (Asclepias amplexicaulis), tall green milkweed (Asclepias hirtella), purple milkweed (Asclepias purpurascens), butterfly milkweed (Asclepias tuberosa), white milkweed (Asclepias variegata), horsetail milkweed (Asclepias verticillata), and spider milkweed (Asclepias viridis).
If you have already planted non-native milkweed, experts advise that you cut the tropical milkweed back every few weeks during the winter. And, of course, plant more native milkweed. You can learn more about planting native plants on the native gardening webpage of the Arkansas Natural Heritage Commission.