Stopping erosion on shady slope

Asked October 11, 2017, 9:55 PM EDT

My homeowners association is clearing invasive vines on the side yard of the private property of one of our 86-year old neighbors. At the side edge of his 2-acre property is a slope about 250 feet long and 10-20 feet wide that runs parallel and down to a biker-hiker path. Vines include mostly Oriental BIttersweet that are entangled in many tall old trees up to their tops--primarily Tulip Poplars and maples--perhaps 20 of them and many scrub trees, whips, and mangled black honey locust. Many smaller trees are so entangled we don't even know what they are. We will try to protect these bigger trees and just cut out the vines as high as our climbers can go. We also will have to cut down many scrap trees and vines running along the leaf-covered dirt. The questions are tor after the selective clearing is done. What are the best ways to prevent erosion over the winter? the future? Do we leave the leaves there? Once we cut out the dead and dangling trees that are growing sideways over the paved path in search of the afternoon son, can you suggest a grass mix for shade and to prevent erosion? It is too irregular to try to mow anything but two or three widths of a lawn mower adjacent to the hiker path where we would continue to mow down the vines, weakening the root structure. Plant Pachysandra? Ostrich ferns donated from another neighbor in any of the more open spaces when we finally can see what the space looks like? Do fresh wood chips hold the soil after we hire a company licensed to spray the weeds in the spring as they are growing?? Help!

Montgomery County Maryland

3 Responses

You have quite a job ahead of you, but hopefully we can make it easier.
Oriental Bittersweet is a tough vine to control.
Take a look at this link of some of our worst invasive plants
Here is a publication that lists controls you might consider, especially if you want longer control without using any climbers:
With this method, you cut the big stems, then immediately and carefully 'paint' the cut surface with a non-selective herbicide, which is absorbed and sent down to the root for a complete kill.
Brush B Gone is one type of non-selective, containing the active ingredient triclopyr. The link above shares others.
Anything that you plant should be native to our area. The ostrich ferns are a great idea. In shady areas, if you can do it soon (like this weekend) you could seed in fine fescues- hard fescue is best. We'd skip the pachysandra and look for native possibilities.
Here is a link from our website with ideas, and
here is a link to the Maryland Native Plant Society :
You didn't mention how steep the slope is. If it is extremely steep, you may want to hire a landscape architect or a landscaping company to use a stabilizing mat, while seeding or planting for you.


A few more specific questions:

1. The crew I intend to use on Monday for clearing are not licensed to use pesticides/herbicides. Do they need to be licensed to spray in this area on private property?

2. The new county law re use of herbicides has been overturned. Can we use the herbicides in the spring as vines are starting to grow and thus we cut and spray--one worker following the other? The herbicides work through the vines' leaves.

3. I would like to use the hard fescue grass and hope it can grow in shade and sun because then we can mow down future growth of vines. Do we do both things?-- Herbicide now after the cleanup and plant grass seed in spring when the vines and old berries left in the ground may start growth again and we can mow them down? Or forego herbicide now and plant now then hope to mow in the spring to keep down vine regrowth? It is not a very level area and some steep areas. Will have to see after the BIG cleanup on Monday.

4. Or can we leave the leaves that fall this season on the ground? They don't seem to prevent spread of the vines. Do wood chips put on the steeper part of slope just wash away?

Tricky questions.
The herbicides are not ones that the average person needs licensing to apply. (Glyphosate is the active ingredient found originally in Round-Up, but is now under multiple labels. It kills any green tissue/leaves it contacts, and can be used in the cut and paint method as well).
Are you hiring the Monday crew? If they are paid workers, they would need to be licensed as a business and as certified applicators under Maryland law. If they are volunteers, they would not.
How does the man you are helping feel about what you are planning to do?

The way of cutting and painting a vine lessens the amount of the herbicide used, requires no climbing, and lessens the chance of accidental applications to desirable plants you wish to keep. Additionally, fall applications tend to work better on woody vines and other invasives as energy is being directed down into the roots this time of year, so the translocation of the herbicide is even better.

If you can, we would use the herbicide now, AS you are clearing, being sure to carefully read and follow all label instructions.

Our timing recommendation for grass seeding is to have it down by October 15th.
While you could do it later, as it gets colder the germination rates decline, and newly sprouted grass could be harmed by heavy frost. It is a judgement call.

So you know, fine fescues can take less foot traffic and need to be mowed less often than sun-loving turf-type tall fescues. That sounds like a 'plus' for your area.

You can leave the leaves that fall as groundcover. It enriches the soil as they decay- it's how forests do it.
Wood chips are not recommended, as they do wash away.