cloudy christine, The siding I have been using is @ 9" tall by however long I can find. That means the trench has to be @ 9 1/2 inches deep, by 4', 6', 8' long, so that the top edge of the siding is just below the dirt surface. The siding is laid in the trench horizontally. You don't want it below the surface too much, otherwise roots will find their way over the top and back into your yard. The "ends" are overlapped as you continue on with the trench. Today I was adjusting some patio block that I have under my chain link fence (which makes grass trimming so much easier and also keeps animals from digging to get under the fence). I had to laugh, because I put the siding (root barrier) along the fence over a year ago, so as I took the block out to fix the dirt under the block, there was the root barrier with all the forsythia roots bunched up on the other side. They couldn't get thru. It made such a difference in my raspberry patch last year, not having the neighbors forsythia roots sucking up all the nutrients. It is a lot of work, but well worth the effort. You have to do a little at a time, and it will eventually get done! I don't know of any other way to stop the roots. I did the same thing on the other side of my yard where I have my tomato garden. The other neighbor has a huge pine tree about 4 feet from my fence. You know how it is, everyone has to plant their trees along the property line, forgetting that they will grow up some day! Every year when I till the garden, what do I find? Yep, pine tree roots. I put the siding root barrier in that area and now I don't get any roots in the garden. Paul

Thanks to all for the replies. kato_b: I don't think grass would work. It's kind of an awkward area, which is probably why someone planted ivy there. There's a rock retaining wall at the back of it, cement stairs and sidewalk boardering it on one side, a cement sidewalk with raised cement border at the front and a cement slab boardering on the neighbor's side. It's also sloped. I'm reluctant to plant anything there because we've been battling poison ivy in that area all spring and I think it will continue because the neighbor isn't controlling it on her side. I don't have the patience to keep killing it off while dealing with desirable plants in the area. Is the main problem with landscape rocks dealing with the debris that gathers in there and trying to keep it looking tidy? Does plastic make it worse? Does using larger landscape rocks - like medium sized river rocks - make the problem better or worse? Wood mulch could work but I'm afraid it might tend to wash away because of the slope. Maybe I'll just let whatever the neighbor has on her side take over (except the evil poison ivy) and move on to the multitude of other projects we have to complete this summer. Gotta pick your battles. You know, gardenweb should start a forum with tips on how to live in peace with difficult neighbors who share a property line. This neighbor just cut down 3/4 of an old evergreen shrub that was on the line and left the mutilated remains on my side for me to deal with. Is that passive-aggressive or what! It's going to be a long summer.

Thanks Kudzu! Another question, say a rhizome penetrates the barrier say 20 inches down, will it have the tendency to climb strait up to the surface again? I am wondering if rhizome pruning on the other side of the barrier would be a good preventative measure. My fence line is 2 feet or so from my longest running barrier, and about 15 feet from the fence line on a couple of others, and I want to do the best I can to prevent the Boo from invading my neighbors property. The barriers in question are containing Bissetti, Rubro-Marginata, Vivax, Henon, Bory, and what I think is some Aurea. I know that pruning on the side with the Bamboo is a good idea, but it I think it may be too late for that in some of my contained areas.

1) Only concrete or cinder blocks/bricks contain my raspberries, otherwise they spread freely. You might be able to get by sealing just the 12 inches closest to the fenceline, while leaving a gap for drainage and deeper root penetration, but not 100% sure. Berries and redwoods have to be some of the toughest root situations around, not certain I'd trust only rocky soil or wood as a barrier to them. You never want to damage the neighboring redwood tree roots or leave them exposed to sunlight too long during digging in any case -- you can accidentally trigger them into sprouting on your side of the property! 2) Yes. 3) Box stores and some nurseries have them right now.