'Clear cutting' is unlikely to solve your problem. And neither is planting something with the hopes it will shade out undesirables. You really need to scrub out all the unwanted stuff including the roots. You will still have issues with existing seeds that may sprout but any seedlings resulting from those should be easy to remove if you are prompt.

Sometimes it is easier to do this in sections (unless you hire a crew to come in and do it all at once) and replanting the cleared areas as you go. This will prevent unnecessary exposure of the bare slope to erosion. But you do need to have a plan in mind for the replanting before you start.

Not knowing where you are located makes it difficult to suggest what to plant but in general, broadeaved evergreen shrubs and groundcovers will require the least attention and if you select for an appropriate mature size, the least amount of pruning.

After removing unwanted plants by the roots in a section, use a weed-preventer to stop seeds from germinating. Plants that are too difficult to remove down to the roots, spray with Round-Up then remove after they are brown and dead. Repeat the process as needed. When things are clean enough, plant your selected choices (we have no idea what your climate is so can't suggest specific plants). Then -- very important -- put down a layer of mulch about 4 inches deep to discourage weeds from germinating. Those that do make it through the mulch will be easy to pull. It's a lot of effort up front, but once you do all steps maybe 2 or 3 times, you'll have it under control. To summarize:

1. 1) Remove unwanted plants by roots or spray with Round-Up

2) Apply weed preventer

1. 3) Apply mulch layer 4" deep

When under control:

Plant and add mulch again if needed.

Ditto kiminpl. I would temporarily move the plants you want to keep (into pots or another area of the yard). It will make it easier to remove unwanted root systems. Then use a total vegetation killer to make sure those unwanted plants don't come back.. Ortho Ground Clear is a total vegetation killer. To speak more about this, call Ortho Customer Service at 877-220-3089. They are extremely helpful.

Corrugated cardboard works wonderfully under mulch to suppress weeds. You can even pin it down with landscape fabric pins on a slope. It eventually decomposes, unlike landscape fabric. Nice thing about it is you can easily cut holes in it to plant things. I get mine from dumpsters outside of places where lots of food comes in, like a restaurant or grocery. I would emphasize putting in a nice groundcover and then have some prettier flowers springing up in between. Will take awhile of intensive management to get it established, then not so much, so I second the suggestion to take it on in phases. Like first establish your groundcover, and then you can intersperse flowers if you like.

Time to hire a professional landscaper who will cut to the chase and take care of the problem. We had black dirt that was loaded with bacteria and all kinds of weeds. We finally had a landscaper come in, scrub off the topsoil and lay down sod. It was worth the cost.

Some great suggestions--although I have to say I'm probably not inclined to use roundup or other weed killers to fix the hill. I like the idea of broad leaf evergreens as general cover--and I think that using cardboard that would decompose versus a landscape fabric makes more sense to me. I also agree that the actual work of just physically clearing sections of roots is probably the best answer--but how to achieve that while keeping my back and my bank account intact is another story.

BTW--I'm outside of DC in zone 7A, so pretty good growing conditions here. The hill certainly thinks so.

We have a very similar hill and while I still haven't figured out a true solution, one thing I will tell you is NO LANDSCAPE FABRIC. The former owners of our home covered my hill with plastic and weed fabric, and the weeds just grew right on through, securing the fabric to the ground with their roots. The handful of desirable plants on the hill were starved for moisture and were dying off one by one. We removed the fabric and plastic last fall - it was a truly Herculean task - and found that the roots of most of the desirable plants were running just under the surface in search of water and nutrients. I mulched the whole thing and now I am just waiting for the mugwort forest to reawaken so I can kill it off and try to plant things that will actually look good. I'll be following the suggestions on this thread with interest, but I needed to sound the alarm on the fabric! Just say no!

Our black dirt was heavily infested with weeds that we could not eliminate and must have come from a construction site or from acreage. So soil was removed and redressed. Looked exactly like the poster here, so I know whence I speak and got advice from a professional landscaper.

Biondanomina--so interesting to hear your experience! I had gotten some hints that landscape fabric might be less than ideal through some of my own research, but didn't want to crush the neat and orderly dreams of my husband. And taking a quick peek at your page--looks like we are striving for the same kind of lovely planted hill. Love the pics you posted!

There are very few weeds that cannot be controlled with just some effort and elbow grease :-) Japanese knotweed or horsetails are two that come to mind that may require some extraordinary efforts but most anything else can be successfully grubbed.

And several of the comments within this thread are coming from professional landscapers or horticulturists. I deal with similar situations like this frequently!

gardengal48--the sassafras kill me. Those roots are deep and so strong! It's like entire trees buried feet under the earth. And if I don't stay on top of the mimosas they get huge overnight. I feel like we should be happy that we've made any progress considering where we started.

You won't have to use herbicide forever, and it breaks down eventually. So as long as you follow the application instructions it is a lot better than repeatedly disturbing the soil with various tilling methods or removing it. And I would assume you would want something other than grass on that hillside so you won't have to mow. As with most endeavors, you'll probably have to use a combination of methods to get the desired results. I use the herbicide "Snapshot" (Triflurilan) to suppress the sprouting of new weeds between my plantings. Does not kill the plants but kills the weed sprouts. Corn gluten has a similar effect. One the plus side, these pre-emergent weed killers will give the plants you are trying to establish a break, and also your time and back. And in general, they do not move out of the zone of application to affect other parts of the ecosystem. and will break down. On the down side, from an organic perspective, they probably aren't the best for keeping your soil healthy, kind of like the way antibiotics kill both the good and bad germs, but the exact mode of operation of soil bacteria in soil health is so generally unknown that it is hard to say for sure what the downside really is. I use them in accordance with IPM practices and for very specific applications, i.e. areas where I know the effects will be very localized, which is similar to your situation. I also use compost to re-establish healthy soil micro-organisms. But, you don't have to use chemicals, you can just weed the area, it isn't that big. I have a big area so I hand weed, till, and just about everything else. It's going to take some effort at first, because it will take several years of weeding at least to get the seed bank of your soil cleared out of the undesirable weed seeds. That's why I suggest you may want to go all out at first. But if you are totally opposed to herbicides, then have at the weeding. Nothing wrong with that. Fire is another great way to deal with this problem, but not applicable in your site. You could also lay down some black plastic, pin it down with landscape pins, and then wait a few weeks and pull it up. The combination of heat and lack of water and sun will kill off a lot of the top vegetation.

I am coming to the party late and skimming replies so this might be repeat. I caught Biondanonima's recommendation to skip the weed barrier/landscape fabric and "second" that this is good advice. As she says, weed roots grow through it, locking it to the ground but doing nothing to stop weeds.

While the "surprise" plants might be welcome when they come, they might not be the basis of a good design unless they are in sufficient quantity. It would be hard to predict how you might use unknown things. Maybe you can get these plants identified and quantified and then someone might be able to calculate how they might be used. Keep in mind that too many different things, randomly organized, can make the yard end up looking like a junk repository.

If we were to "dissect" what architectural element (floor, ceiling, wall, furniture, etc.) would be the most important in creating a nice finished product out of this slope, it would be a FLOOR. With that element alone you could have a pleasant, serene looking space. (Some walls and ceiling -- tree canopy, retaining wall and fence -- are already in place.) While a floor ALONE might not create the highest glory, it is the beginning. I suggest you begin with a groundcover that is low (so as not to feel oppressive to the adjacent spaces) and does well for your area. If it was evergreen that would be a "plus" but whether you can have it that way depends on where you are. In addition to a groundcover, other plants will help add more interest, but it's hard to make much in the way of specific recommendations because we cannot see a cohesive total scene or a "to scale" plan of the area. I suggest you draw a simple plan showing the existing major elements. To show a complete scene, place the camera at a central position opposing the scene, and then take a series of slightly overlapping photos that pan the scene from one end to the other.

In addition to a groundcover, it's likely that most other plants will be placed at the back of the scene, not the foreground. There is no point to screening the back of the scene, which presumably you will make look good, with taller plants placed at the front. Other plants, if they are single, must be large enough if they are to captivate an audience. If they are not large enough on their own, they must be in groups that are large enough. Having small, unrelated plants does not make a nice scene.

Unless you are creating a "wall" (hedge) as a backdrop, avoid placing plants in lines. It usually doesn't look good. Instead, place them in masses/blocks.

For the shade: Ferns are for shade, but don't they like moisture....? what about low spreading evergreen ground cover?

We are in the same area so we have a lot of the same plants/weeds. If I understand you correctly, you put in a huge effort whacking at the hill, plant some plants and then leave it to its own devices. One reason the weeds often win is they are tougher than most ornamental plants.

For my weedy "woody" area, the only thing that keeps several invasive vines and weeds at bay is going out several times a summer and pulling when they are TINY. It usually happens as I take a stroll around my plants (something I enjoy) and I just lean down and pull up tiny plants as I go. Let them get bigger than a few inches and yes - those suckers won't come out without a fight.

I'm basically saying that after the big effort, a walk around after a good rain and pulling out little things can prevent another huge effort in the future. I'm not above very judicious use of weed killer especially for poison ivy. However, maintenance can be lots of mulch (several inches deep - you would need possibly 15 - 20 bags for that hill) and a few walk arounds every so often to pull whatever grows through.

The weather was so lovely today it inspired some time on the hill--the weeds come out pretty easily right now....BUT THERE ARE SO VERY VERY MANY OF THEM. I think we are starting to come up with some plans--taking into account a lot of what has been mentioned here. I greatly appreciate all of the advice!

After I spent some time weeding, I also dug up and divided up a rather large poorly placed hosta from another part of the yard and planted that in the area right behind the wall. They seem to be quite hardy, don't mind shade, and I was able to come up with enough parts of it to cover the entire wall area near the screened in porch which we will plan on keeping aggressively weeded. I'm hoping this can be the beginning of the "floor" referenced by Yardvaark(9A).

I do need ideas for the back of the hill near the fence--I'm thinking we might plant 7 or 8 very mature evergreen shrubs--but evergreens that aren't in the pine family. I'm thinking something like Rhododendron or Viburnum rather than juniper or holly type of shrubs--but any suggestions would be welcome! I think our plan to keep that area fairly clean will be lots of mulch and maybe rocks?

Still working out how we will deal with the middle--but I think everyone has convinced me that landscape fabric is not the way to go. The sunny side I think will take more care and time--especially since I get such a lovely range of flowers on that side, so worth cultivating the plants I want to thrive.

I'll also check out the plants suggested by Dig Doug's Designs.

Thanks all!

I'm trying to decide upon a broadleaf evergreen (or two) for my hill as well - kalmia (aka Mountain Laurel) is a strong leading contender. It's in the azalea/rhododendron family, but IMO the flowers and foliage are a bit more interesting. Pieris japonica is another one I like a lot.

Those are striking plants--especially the Mountain Laurel. I have some more research to do before I decide!!

I meant to say something about this but just forget. And later I saw the mention of something to the effect of ".... probably wouldn't use Round-Up....." OK. Imagine a professional baker coming to work but refusing to use the large electric mixer because of a belief that bread dough is best when hand kneaded. In today's world this baker could never physically accomplish the work that was expected of him. While it is possible to to eradicate weeds by various "hand" methods, it is also vastly slower, more time consuming, and less sure than by using the same methods a professional would use. Personally, I think the objection to Round-Up (glyphosate), and some other common herbicides, is misplaced. These break down in relatively short order, and are relatively user-friendly, if one uses ordinary precautions. If one were to remove (or cover) any plants worth saving, spray the rest, and mulch the hill, that would get rid of all the easy-to-get-rid-of weeds (90%) and leave just the difficult ones (10%) which could either be dug out or retreated. I bought one property that was entirely (except for where the house and driveway sat) like this hill. By the end of the first summer it was weed-free and mulched. One can choose to attack a problem by archaic means if they wish, but if there is a cost in time, effort, or delay, they must pay it. Here, there will be a cost -- mainly in delay and effort -- and it could be substantial.

In Ontario, we are not allowed to use Round-up or the like. So....get rid of all the weeds/roots, search for erosion control plants that suit your light requirements. Fast covering ground cover, shrubs planted tightly will help with weeds as well. Aim for natives and you'll get lots of bird/insect activity which is a BIG part of enjoying the garden. :)

As crazy as it sounds, look along roads/highways and see what your city is planting along the slopes. Use your hill as a calm green backdrop and maybe plant some urns with ornamental flowers that can be changed seasonal. :)

Here is a start:

http://www.finegardening.com/article/shrubs-for-slopes

https://www.nature.org/ourinitiatives/regions/northamerica/unitedstates/nativeplantszone7.pdf?redirect=https-301