When and How to Easily Spot Invasive Plants

As the winter season transitions into spring, before most trees have begun to break bud and leaf out, take a look at wooded areas and along roadsides. Have you ever noticed how some plants seem to “green up” many weeks or months before other species? The plants which begin to leaf out earlier than other plants, are most likely an invasive species. In Indiana, you will begin seeing invasive plants leaf out in as early as February/March, ahead of when most of our native plants begin leafing out around April. Invasive plants are also among the last to drop their leaves in the winter. So again, once trees lose their leaves and our native plants begin to go dormant, many of the remaining green plants you see in the last fall/early winter, are likely invasive (aside from native coniferous/evergreen plants). Due to their longer growing season and shorter dormancy period, invasive plants are easy to spot on the shoulder growing seasons.

What this means and why you should care.

The major ecological problem with invasive plant species is they grow and reproduce aggressively while outcompeting our native plant species for the same vital nutrients, space, sunlight, and water. Because invasive species have a longer growing season, they are also able to better compete for available space as their growing season begins several weeks earlier than our native species, which gives them a “headstart”. Invasive plants also reproduce and establish faster than our native species, as well as respond better to human disturbances; they are among the first plants to occupy a newly disturbed area. In areas containing a dense invasive plant composition, sunlight has a harder time reaching the ground, native seed sources are diminished, thus drastically hindering the forest’s ability to naturally regenerate and produce new, native plants. Over time, this process/issue continues to “snowball”, with the area containing fewer and fewer native plants and an increasing invasive plant composition. Invasive plants provide little to no benefit to wildlife and result in the decline of native plant species crucial to wildlife as well as our economy. Without human intervention, our native plants will struggle to survive and will continue to decline over time, as well as the wildlife species dependent on them.