Depending on how overgrown the area is, there are a couple options SCEPPC recommends for dealing with invasive plant species.
There’s a natural hormone in all plants called indoleacetic acid. This hormone is what allows a plant’s root system to form and grow. It’s also what’s responsible for creating the characteristic crown of any plant. The crown of a plant refers to its above ground parts – stems, leaves, etc. Crowns are what make Cedar trees triangular and Oaks more open, for example.
We can also thank this hormone for our problem with invasives. It’s what keeps them sprouting! For this reason, it’s imperative to cut beneath the plant’s crown (see photos) so that the root left in the ground cannot sprout back. If you cut above the crown, you have left a completely developed root system that still has a high concentration of indoleacetic acid, which spurs growth.
Manually removing crowns of invasive plant species is definitely the most ‘organic’ way to go. No chemicals involved – just lots of hard, tedious work. If you’re able to go this route, Bill suggests using a hand saw and/or a Pulaski axe.
Manually removing each individual crown is labor-intensive, which is why we have to turn to chemical sprays for a plot like ours.
SCEPPC President, Bill Steele, recommends adding food coloring to your spray so you’re able to keep track of where you’ve been. Within 7 – 10 days, you’ll start to see leaves yellow and die. It takes up to 2 weeks for the plant to die. If you’re looking for gear, Gempler’s is a good place to start. Bill recommends using a backpack sprayer with a 14.5 PSI constant-flow valve, and setting the droplet size to large. Be sure to check the weather beforehand. You should avoid spraying before or immediately after a rainstorm as the oil needs time to soak into the bark.
There are a number of chemicals available for killing invasives. Basel, for example, works great for Mimosa. Basel should be sprayed from the groundline to 10 inches above. If you’re spraying a stem (3 inches down or less), you only have to spray one side. Anything larger and you’ll want to spray all the way around and all the way up to 10 inches.
DOW Milestone is recommended for Kudzu, while Triclopyr works best for Chinese Privot and Bradford Pears.
If you don’t feel comfortable removing invasives yourself, Bill Steele recommends the Marshfield Forest Services. They have experience removing invasives in state and federal parks.