I wouldn't mind having a better look at that wall before suggesting something with a lot of root mass, like daylilies or shrubs. There is not much lean on that wall and pressure from within is the last thing you want. I've been poking around my rock walls and garden lately and have noted how much root mass is tending to migrate to areas of consistent dampness. For example, I have a pot standing next to a plant that has a bulky root mass, and although the plant can grow best where there is light, the woody base has pushed itself under the pot. Quite intriguing. In your situation, this tendency is aggravated by the downhill slope, which is where water, and thus roots, will go. Therefore a plant that spreads by stolons would probably not grow uphill, but you may not want to risk it - so none of your Houttuynias or St. John's wort, for example. Something that mats, in contrast, could easily by mowed by the neighbour (or their mowing people). A couple of matting plants that I have had good success with are a spreading veronica (note to self and others: do NOT google "spreading veronica") and a matting dianthus with bright pink flowers. Not sure how they would handle full sun in your climate, but the moisture retention of the rock would help. I think the thymes would be OK too. Which way they spread would partly be determined by the sun - they would grow primarily toward it. I agree that the sedums are not as weed-suppressing as you might think. One that might be would be Sedum 'Angelique', and there are others. Sedum acre would probably also work - but as Yardvaark's description of how to root it suggests, it is rather easy to propagate and so your neighbour's mowing might get it all over her yard - so easy to miss a bit that falls. 'Angelique' will also root where it drops, but because it's bigger and not as fragile it is easier to control the bits. All ground covers need periodic haircuts to avoid getting leggy, woody, and sparse. KarinL

yes Ken, you'd think that would not be allowed. Our problem thus far has been that here,there are very few concrete zoning laws to protect homeowners, and those that are on the books are sometimes hard to get enforced. No set back rules, etc. We've been told by various people that they much prefer the homeowners hash it out themselves in court. Well, needless to say that can get pricey, so we have to weigh what we'll get out of it if we go that way. We did get the city to tell them the fence, which was originally at 4' from the back of our property line all the way to the front sidewalk, had to be lowered to 3'in the front yard. Now we're just waiting on the "decorative only in front yard" to be upheld. We've been corresponding with some good people and are hopeful that this will happen. The ugly thing is so close to our house it looks like it's ours, people have asked us about it. This guy lives on the corner facing a side street, so he doesn't think that front yard rules apply to him, or so he says. He's a pusher, and it's all about what's his. If he could stand in the middle of the yard and urinate on the lot line to mark his territory I believe he would. LOL! In the meantime we are trying to make the best of a very bad situation, by seeing what we can do on our property to camouflage his fence and give ourselves a break from looking at him. The distance between our homes gradually widens as it moves into the back yard, so we have more options there. But narrow growing, perennial,evergreen type plants that can be kept to 3' are hard to come by.

The very nature of a vine is to grow as much as possible and all can become "invasive" after awhile unless vigorously controlled. The 3 you mention will grow to cover the fence but you'd have to keep after them as they can also crawl along the ground and get into any nearby trees or shrubs. You may want to consider clematis - perhaps mixing types to get blooms from spring through summer. Some of the type 3s can grow quite strongly but can then be cut back to a couple pairs of buds each year. The type 1s & 2s can form a woody trunk that would remain in place to resprout new growth.

We have a similar situation; a medium sized suburban yard with a mish mash of chain link fence. Replacing it with a privacy fence would be very difficult because a long stretch of it goes right through the middle of 40+ year old thicket of honeysuckle bushes with massive trunks and roots. They are great for privacy in the summer, but do almost nothing all winter. Neighbor has three motion lights that shine right in our windows much of the year! On one section with no honeysuckles we got the rolls of 6' reed fencing and tied it the 4' chain link with wires. It held up well for a few years but the wind and animals trying to climb it damaged it a lot. The wire holding it together is thin and starts to rust and break after a few years too. Cutting it back to 4' when it got ratty helped tidy it up a bit, but obviously a lot less privacy. It is a very temporary solution at best. Since your fence is not even on the property line, I concur that getting a new and more private fence pushed back to the line is a better solution. If that doesn't pan out though... the reed fencing is an option. Ideally you would pair the reed fencing with some type of evergreen shrubbery which will help as well. They help with noise too. We have a massive silver maple and previously had several in our yard and next door. Yews would grow under them, slowly at least. Sweet woodruff is a good groundcover for dry shade too, although it is not evergreen. If you do put in any shrubs, plant them far enough away from the fence so they have room to grow. I have seen our one neighbor out with a scissors cutting off just the very tips of our red-twig dogwoods that stick through the fence. People are strange.