Last Thursday, we helped Wildways prep a 90' pollinator strip along Intervale Road. Pollinators are on a worldwide decline and need our help. Pollinating insects are essential for our food systems and wild plant survival. Not only do we count on pollinators for our food, but they aid in the reproduction of plants that sequester carbon, prevent soil erosion, and proide substance for fibers and raw materials.
Before we can start planting homes and food sources for our pollinators, we needed to eradicate the invasive plants and weeds that are growing on the plot. The area is filled with various grasses, Japanese hops, and garlic mustard. These plants can quicky take over and prevent the establishment of native species. Japanese hops will even go as far to strangle anyone who gets in their way. Garlic mustard "nips it in the bud" by releasing chemicals that halt the seed production and germination of surrounding plants. Most invasives won't go down without a fight. We implemented three different methods of invasive removal to clear the plot; these three methods will also give us insight into which techniques work best in this particular area. First, the entire area was weed-whacked. Then, we split the 90' plot into three 30' subplots where we tarped, solarized, and sheet-mulched.
Tarping is simply laying down a piece of black fabric, which starves plants of sunlight. Tarping is the cheapest and easiest method, but timing is important because depending on the species or life-stage, there may already be plenty of starch reserves to get the undesirables through the dark times. Tarping for too short a time allows invasives to resprout like nothing happened; tarping for too long can kill off all of the microorganisms in the soil. It's best to tarp in the early spring before the plants have regained their strength. We could be too late, but we're hoping that by late fall we'll be good to go.
Same goes for solarizing. Solarizing is essentially the opposite of tarping-- you lay down a clear piece of plastic so that the plants cook until all of their roots and shoots are dead. But the timing is more or less the same idea: cook until the invasives are wiped out, but don't completely destroy the soil. It's also important that the area you're solarizing receives enough sunlight, otherwise this method may not be effective.
Sheet mulching is the most time-consuming method, but it makes use of different soils and plant fibers to suppress weeds and renourish the area. I also like that it doesn't require putting down a big, ugly tarp for months at a time. This method was wet, dirty, and fun. We started with a layer of compost, followed by a layer of wet cardboard, wasting soil, and mulch. The compost helps stimulate the microbes in the soil while the cardboard helps suppress the regrowth of weeds. The wasting soil and mulch help retain soil moisture and health. Although dunking cardboard into puddles and shoveling takes more work and calories, sheet mulching is a great way to get your hands dirty and feel connected to the earth.
This project helped us think about possibilities for other patches of invasive species that grow within the various parcels managed by Wildways. It was also a great way to engage with the Intervale staff and learn how to think like land managers and conservationists. We hope to continue projects like these throughout Burlington and find ways to get a broader range of people involved.