I have a similar area, multiflora, brambles and forsythia, not to mention box elder and black cherry which are native but a pain. You're going to have to keep at it for a few years because the whole mess will come back from roots and seeds. You can mow or hit it with round-up in the spring but be careful because you might have some nice native surprises in there - I found jack-in-the-pulpit, and dogwood and redbud saplings.

And the birds will perch in the trees and replant the roses, along with poison ivy.

I agree, don't be in too much of a rush to replant the area. Some of your invasives will no doubt re-appear, anad it will be easier to manage them if they are not mixed among new plantings. And you may be pleasantly surprised by native plants that were suppressed by your invasive swarm! Eventually, there are many ground layer plants and understory trees and shrubs that would be appropriate for your area. A good idea would be to do a little research in nearby nature areas.

Since this is a large area, planting is out of the question. I'll just have to expect the unexpected. I've kept all the non-invsive tall grass and tree seedings. I'll just have to continue monitor and maintain the new areas.

There will be more cleaning inside the woods. It is so distressful to see all the invasives unchecked. Nothing seems to stop them...

If you have a source for the seeds, jewelweed is a great annual cover crop,if the areas not too dry or too sunny.The seedlings grow fast and cover open ground, outcompeating invasives such as garlic mustard.Once established then will continually reseed themselves untill the perrenials return.

Oh how I wish jewelweed would outcompete garlic mustard here. And stilt grass. And all the nasties. I just mowed and re-sprayed the area I cleared last year - forsythia, euonymous, multiflora rose are determined little boogers. So are the black cherry hordes.

27 jack in the pulpit seedlings - they had been shaded by the forsythia - were moved to a shady nursery bed. Found wild strawberry - birds bring something good now and then - and pulled out lots of Indian strawberry.

I am tending some shrubs and infant trees - azaleas, sassafras, dogwood, hop hornbeam and calycanthus - but deliberately planting anything smaller would be a huge mistake for some years yet.

We use blue fescue to out-compete the garlic mustard, and it works like a charm. The fescue doesn't supress native plants, nor will it survive being burned. Which leaves us the native plants.

Hmm - that's another "works there but not here." I couldn't even establish blue fescue in my garden bed.

achang89,
I have been removing invasives both from my property and as a volunteer for our local park district. I have lead crews to remove invasives from several local parks.

For invasives that propagate by seed, it may take 2-5 years to clear an area. I have been pulling blackberries from my forested land for 4 years now. I did not spray a weed killer, because I have native plants that I want to keep. Of course, I have deer who are now browsing the multiflora roses that I cut down from 15 feet to 3 feet high.

You may want to plant native shrubs and nuture them to fill in some of the open space. Why? Well, plants engage in "warfare" in the root zone. It's just possible that what you plant will suppress the growth of the invasive plants. I have already planted many native plants with the hope that they will fill in the space. And I have noticed that the birds are very happy to have new cover.

If you are working in a forested area, you may find that once you remove the invasives, the land is pretty barren. What I have been doing is making small piles of branches (noninvasive stuff) and wood that can serve as shelter for wildlife. Of course, it isn't landscaping or artistic, but I'm trying to restore the forest understory. I also have many native blackberries in bloom now.

Good luck to you...