Unplanting for the Pollinators

We’re wrapping up National Pollinator Week. We focus so much on “planting” for pollinators, but there are times when we should be removing plants in order to support our pollinators. You ask, “How could removing plants possibly help our pollinators, don’t they need the plants to survive?”

The answer is “Yes, they do need plants to survive.” They need specific plants to survive in most cases. The poster insect for this point is the monarch butterfly which needs milkweed (Asclepias) plants to survive. The adult butterfly can nectar on many plants, but without milkweed for the baby caterpillars, the monarch will not survive as a species.

The same is true for thousands of Lepidoptera species (butterflies and moths). These insects have evolved with plants from their local ecosystem and depend on them for food. Likewise, pollinators like bees have plants that they evolved with: short and long-tongued bees nectar on specific groups of plants. Some bees build their egg tunnels in specific perennials and, should those plants diminish, may not be able to adapt in time to new plants.

Kudzu flower in a sea of leaves

Ok, back to the 'unplanting' – when should we do this? When non-native plants outnumber the native plants then biodiversity starts to go down. An extreme example is when kudzu, that rampant vine from Asia, overpowers an area until it is the only visible plant. The dozens of different plants – annuals, perennials, shrubs, and trees – that lived there are gone.

Butterflies and moths and bees and birds now only have one plant in that spot. Most of them will leave. And their populations will dwindle as they adjust their birthrate to the reduced amount of food.

You would be surprised at people that just let kudzu (or other invasive) grow. They might beat it back a bit to keep the fence clear. Yet kudzu is not the worst offender. There are plants which have taken over more acreage than kudzu ever will. Sneaky plants that people don’t recognize but which are just as unpalatable to North American insects as kudzu would be. Plants that reduce the populations of the native plants that our pollinators need to thrive (and survive). In my area, Japanese honeysuckle and Asian privets have choked out many thousands of acres, especially along sensitive waterways.

English ivy in residential area; foliage also holds water and mosquitoes

How shall we deal with this? We need to be aware, we need to remove them, and we need to educate people responsible for areas that become infested. Parks and roadways are prime areas for plants to move in and overpower the native plants. Ignorance and neglect are the friends of invasive species!

The good news for large areas is that often just the removal of the pest plants will give native roots and seeds a chance to sprout and grow. Native plants can rebound. In severely degraded areas, replanting may be required.  Each situation needs careful consideration of the site-specific conditions.

Got milkweed? Monarch on Asclepias tuberosa

A tiny carpenter bee works the equally
tiny flowers of mountain mint
(Pycnanthemum ternuifolium)

Check your yard for the balance of native and non-native plants and consider how it really supports pollinators, not just their adult form, but their larval form and nesting needs too. Once we have restored a balance by 'unplanting' some of the non-native plants and incorporating regionally native plants, we can better support our pollinators again.

I wrote one of my favorite blogs on Pollinator Week in 2011 and you are welcome to read it here. It has lots of plant suggestions.