Ask Mr. Smarty Plants

Wow! When we get canyons like that in Texas, we call them state parks and charge admission. Of course, it has quit raining here, so we haven't had any new parks open up recently.

To be honest, we think this is probably beyond the scope of what we can do with native plants, or maybe any plants. Our specialty at the Lady Bird Johnson Wildflower Center is the care, protection and propagation of plants native to the area in which they are grown. It sounds more like you need a firm of civil engineers than advice from gardeners. If mature trees and Japanese knotweed are unable to hold their own against the erosion, we can't think of anything else that could. This doesn't sound like a feature that could have been hidden beneath a neatly mowed lawn. Did you have some plans for the site when you purchased it?

Because we don't know zip about construction of retaining walls, etc. we tried to find some websites that could at least give you some ideas of where to start. This first one is actually from a California nursery. They do recommend some plants, but they are all suitable to California. Las Pilitas Simple erosion control for a hillside or garden slope.(California) Another site from the California government has some more ideas for construction or basic erosion prevention. We realize New York is way different from California, but we couldn't find any sites on controlling erosion in New York. We would definitely recommend that you call in some professionals in site control. If that crevice keeps growing and that bank keeps sliding, you're going to run out of a place for your house.