erosion control after ivy removal

Question

Douglas Fir Root

slope 1

I have cut back some very old ivy on a west-facing steep (50°+) slope but many 3-4" thick roots remain, holding back the bank. I wonder whether I can just intersperse native plants and hope they'll smother any ivy that tries to return...or should I attempt to cover the slope with plastic to kill the roots? It's late spring and the sun beats down on the slope. Soil is very loose and rocky and it's impossible to water given the slope. I'm thinking low oregon grape, salal, and grasses. The location is Camano Island, north of Seattle. Thoughts?

Answer 1

In rainy Washington I recommend a "Dirt Locker" It's a modular retaining wall that can be made big as possible, fights erosion by being a network of mini dams. Water cascades from terrace to terrace.

It's far cheaper than rocks/bricks.

Answer 2

I think native plants will competing against English Ivy with established roots will need a little help. That ivy is tenacious and patient.

I like your solarizing with plastic idea. It will kill a lot of your soil's biome though. It can recover of course, but something to consider.

Ideally you'd just pull the ivy roots out. You don't have to get all of them for it to be productive, and it's not as much toil as it sounds like in loose soil. Any children with idle hands around?

I think you would also be OK with leaving the roots as they are, so long as you understand you have a few years of casual but constant ivy weeding ahead of you.

For your erosion concern, you could mulch it heavily with wood chips. This will stop the erosion, make any ivy that emerges obvious for you to remove, and does all the lovely mulch stuff for the new plants you will be planting. You can even water a mulched slope, no problem. It's extremely simple to 'un-do' when you have a better idea- just turn it into the soil.

Answer 3

Ivy can be an absolute monster. However, if your aim is to prevent slope erosion, ivy can also be your friend. Why not just let the ivy regrow as a low ground coverer? Manage it by (a) keeping it within bounds, and (b) trimming it with a decent hedge trimmer once or twice a year.