Hi,
I've watched your post for a while and I was disappointed that no one responded. I don't feel qualified as I'm from a different region (in expertise as well as location :)) and that is a problem that I think will require a bit more professional knowledge. I have a suggestion, though. Try talking to your local county extension agency. Sometimes they will even make a site visit if necessary (I think this qualifies) and give you their thoughts and advice. You might even luck up and find someone in their employ or master gardener program with genuine experience in this area. Erosion control is getting to be quite the specialty these days.
Best of luck to you and your neighbor,
Ging

Thanks for the suggestion and comments, Ging. Many years ago, I asked the SWCD to take a look at this section of stream on behalf of the former neighbor. They put together a plan for stream bank erosion, but it was limited to the two 90� turns the stream makes in that yard and the neighbor felt it was too expensive. So, nothing was ever done. I'm planning to talk with them again, but the property owner needs to invite them out.

The damage shown in these photos was satisfactorily repaired by the gas company a few years ago and that area between the street and the stream channel has been stable. However, it's dangerous for the new property owner to mow and I was hoping to get some suggestions for replacing the grass with plant material. We expect to get some ideas locally, but I thought I could supplement those ideas by posting a question here. I even posted the same message on the Shrubs forum, asking about a specific shrub. For the most part, they preferred to talk about erosion rather than specific plant material suggestions.

I'll try to follow up if the SWCD takes a look at this situation.

Wow. Read the other post and it just reinforces my opinion that comprehensive reading is a lost skill. Both myself and my husband have run into that repeatedly. Frustrating.
Found this article that might help. The link is to the PDF download and it's got a good many ideas for various plants for buffers, banks, groundcover, erosion, etc. These are plants suitable to your area or colder. (Had no idea it was that hard to find plants to control erosion in any sort of article or format.)
In our area you will find the suggestion is always for junipers. That will also work for you - there are many that are fine in your zone and range from prostrate to upright forms. I like the form and foliage of cotoneasters. There are a good many that are hardy in your area and are great for banks with a good, spreading root system. Some natives that the local fauna would appreciate are Symphoricarpos albus (Snowberry) and Kalmia angustifolia (Sheep Laurel). Both good for banks. Others from the list that looked good: Potentilla fruticosa (Bush Cinquefoil), Stephanandra incisa (Cutleaf Stephanandra), and Amelanchier stolonifera (Running Serviceberry). I've had experience with another variety of Serviceberry and love it - easy to please and wildlife love the berries. The PDF list will give you particulars on all the plants it lists.
The Calycanthus floridus 'Athens'? I'm fascinated by the suckering. We don't seem to have that problem here. In the 'bible' of woody plants (Manual of Woody Landscape Plants by Dr. Michael A. Dirr) by our UGA expert he mentions nothing about it and it's one of his favorite, more studied plants. This guy doesn't pull his punches on plant characteristics, either. (I imagine he's not too popular with some producers when he tells everybody about aspects like that.) I'm wondering if it might be a product of where yours is planted? Something like a hard layer keeping roots shallow... . I'll bet Dr. Dirr would be interested. :)
Really hope this helps and good luck,
Ging

Here is a link that might be useful: Buffer Plant list

ging, thanks for the link. I like the fact that they're trying to add native plants and also remove the more aggressive plants as they update the lists. I've saved a copy to take a closer look. Then, I'll be better informed when I ask the SWCD about this situation.

Living next door, I think our growing conditions are virtually identical. I had no luck with Symphoricarpos or Potentilla many years ago. I'm acquainted with others that you mention, but don't know much about them.

I first read about 'Athens' in Dirr's Manual several years ago. I bought one in 1998 and planted it in an area that is underlain by several inches of crushed stone (limestone) that was placed there by the previous owner, probably in the '50s or early '60s. The plant has done extremely well and we were surprised when it began suckering in all directions. Fortunately, it's planted in a 10-foot-wide space between two driveways. So, containing it won't be too much of a problem. I've dug suckers and shared them with friends. At least two of those transplants are doing very well, but it's too soon to know if they'll be suckering in those locations.

When I got a copy of the latest edition of Dirr's Manual last year, one of the first things I did was look to see if he had changed his writeup of 'Athens' to address the suckering. He hadn't. It's still a fantastic plant for the location where we've planted it. The fragrance is great and it blooms for weeks. In some years it re-blooms. Fall color is good, too. I'm lucky that I planted it where I did!

Can't advise re species, but the buffer plant list is so comprehensive. Would like to find one for this area.

Delighted to see mention of Calycanthus floridus 'Athens. Dr. Dirr gave me one before it was introduced, still being trialed in Athens. I didn't observe any suckering, but it was planted among huge oaks and large dogwoods - probably had to fight to survive with all that root competition.

Rosie, now in Sugar Hill, GA

Hi Restorephoto and Rosie, from Adairsville Ga!
I was going to post again to say I had done some investigating on the web and every result seemed to talk about the 'clumping, suckering' habit of the Calycanthus. Frankly, I was rather floored as that's usually something that would be noted in Dr. Dirr's evaluation. I'm wondering if he has not encountered this in person and therefore is hesitant to include it... . ? Hoping that the poor specimen that I acquired from a failing nursery will survive the winter and I can find out for myself.
I actually was seated by some freak accident next to Dr. Dirr at a conference/symposium dinner. I could care less if you sat me next to George Clooney, but Dr. Dirr had me tongue-tied. :D
Ging

ging, grinning about your meeting with Mike Dirr. My daughter got her degree in Horticulture at UGA when Docs Dirr and Armitage were doing amazing things there. I sat in on classes as often as I could and both Dr. A and Dr. Dirr gifted me with many fabulous introductions. They were really close friends and characters.

restorephoto, my city provides rip rap at no charge for stabilizing stream beds like the one you and your neighbor share. They don't provide the labor. One of my neighbors has an eye popping stream in her backyard that she's had two loads added to, with definitely positive results. Lucky to be in a city like Sugar Hill, GA! Suggest you ask your Public Works Department about this. Planting holes are easily made among the rip rap.

I should try to contact Michael Dirr re the suckering, but haven't had the time. I'd love to have the opportunity to spend some time with him! Ging, I hope you get to find out if your 'Athens' suckers or not, but don't expect to see it for a few years if yours behaves as mine has. As far as I'm concerned, that's the only possible drawback to this plant. Fortunately, I planted ours in a location where it doesn't matter. And, if we move some starts to the neighbor's steep slope along the street, it shouldn't matter there either.

I talked with the county erosion specialist today. The city passes an ordinance a few (maybe several?) years ago making it clear that homeowners are responsible for maintaining the right-of-way between the street pavement and the right-of-way line. He's sending information regarding methods for dealing with a steep bank. He's also sending a list of sources for erosion control blankets and stakes. He also said the city will probably not repair the damage the city's salt truck and tow truck did to part of this area a few weeks ago. Unbelievable. But, looking at the bright side, the neighbor won't need to remove the sod in that area before replanting with something else!

I still need to research grasses. I know very little about them.

I'm still researching, but wanted to mention Cardno JFNew, a business in NE Indiana. I was referred to them and they've been very helpful. They sell a wide variety of native plants. I wasn't able to access their catalog online. So they sent me one. It's nice. It has a lot of information that'll be useful in figuring out how to deal with the neighbor's problem area. I think I've gotten more useful info from them than from any other source to date.

restorephoto, have you and your neighbor examined any of the stream stabilization products in addition to plants? Specifically referring to the rip rap, which could be interplanted - just move enough stone for the planting holes.

Oops, just read two postings up.

You might name your city here - it would become a reference for others looking at city caused damage. Shame on them!

We had a similar situation with the adjoining property eroding and filing in the drainage ditch on our property. We called the township and they came out with a bobcat and widened the ditch in the troublesome area which stopped the heavy rain flows from cutting away the soil. I think they also added some sizable rocks where the water comes out of a culvert and makes a 90 degree turn. -It's been good for 4-5 years. If you have a drainage ditch, hopefully your local hwy dept will help.

gc