Barrier is not necessary for clumpers. However, the tradeoff is that, for a 60' length of fence, you will have to spend a lot of money for a screen of clumpers because they will have to be planted maybe 4'-5' apart to provide a screen. They will also be pretty dense and it will take a number of years for them to expand and merge somewhat. With runners, you can get by with fewer clumps, because they will spread out and fill in relatively quickly, but you have to worry about controlling their growth and their direction of spread.

Thank you for your insightful advice, kudzu9!
If I were to install the root barrier for 60 feet linear length (I was told 8mm thick membrane, roughly 30" deep on two sides transversely) it would cost roughly $500 ($200~300 for materials, $200~250 for ditch digger rental) in my area. A local nursery has a 24 gallon Oldhamii pot for $125 and they said that it can be split into 3. If planted 5' apart as you suggested, I would need 5 pots which cost $625. The other local nursery has a 15 gallon Green Groove pot for $125. This nursery told me I need at least 10 pots with root barrier to cover 60 feet. It seems to me that clumpers are cheaper options, if the root barrier is not necessary. Is this true? What would you choose between Oldhamii and Green Groove? I'd greatly appreciate your suggestions.

Hi Greengroove,
We have a 100' fence behind us, and did a planter just for the bamboo. It was probably more expensive than just getting clumpers, especially in labor. But I've been reading over and over not to depend on the root barrier.

If you have the room, I'd go with the Oldhamii, I have one and it's absolutely striking.

Thank you for your empirical advice, iggypoppy!
May I ask what kind of planter are you using? I was told that plastic is better material than concrete, because concrete eventually cracks and the rhizome will find a way out through cracks. Is this true? It sounds like I need to learn much more about bamboo before doing anything.

Hi Kudzu9,
I'm inclined towards Phyllostachys aureosulcata 'Spectabilis' after I read your comment. I'm thinking of an open-sided barrier with 6~8" berm, so that I can easily prune the rhizome on our yard side. On the fence side, I would install 30" 60 mil. membrane root barrier and make sure for the barrier to stick out 2" min. from grade. If it's for 60 feet linear length, how many clumps should I start with? The local nursery said 10 pots (15 gallon) 6 feet on center, but your comment seems to suggest lesser is ok for runners. I'd greatly appreciate your suggestion.

greengroove-
You're asking good, tough questions! Oldhamii is a wonderful bamboo, but it tops out at about 50'+ high with 4" diameter culms, so I don't know if that is what you really want to end up with as a screen. Also, because it is a clumper, you will have discrete clumps for a number of years rather than a more uniform screen that you could achieve with runners.

Your idea for barrier on only one side is a good compromise, as long as you have the discipline to rhizome prune once or twice a year on your side. It's also healthier for the bamboo in the long run to not be fully fenced in by barrier.

If you are going with spectabilis -- another fine bamboo -- the answer on number of pots depends on how fast you want your screen. If you want instant, full screen, you'll have to space closely. But if you are patient and can wait for it to grow over, say, the next three years, then it can be further apart. The nursery is giving you advice that is a pretty good compromise between not planting too closely, but still having enough leaf mass now to provide an adequate screen. Every 6' should be fine.

I'm also giving you a link to a site where you can look at photos of oldhamii, spectabilis, etc., so you can get an idea of what mature plantings would look like...which is sometimes hard to imagine by just looking at pots of bamboo at the nursery. [When you get to the web site, go down to the alphabetical list at the bottom to find your bamboo.]

Good luck.

Here is a link that might be useful: BambooWeb

Thank you kudzu9! I've made up my mind reading your suggestions.

To save a bunch of money I would suggest replacing the current soil with soil that is catered to the bamboos' nutrient requirements. I have read and experienced that boo grows towards the soil that is best for it. You could try what I am currently doing, it would just be on a larger scale.

I have a small stretch along my fence in my back lawn, about 3.5 feet wide and about 20 feet long. I put the P.Nuda on the left of the patch. Where I planted the boo, and to the right of the plant I tilled and added bamboo friendly potting soil/nutrients. So far the growth of the new shoots has been only to the right of the plant.

So my suggestion is to just till and fancy up the soil in the direction you want the plant to run. If it starts to veer off course, dig up the runner and plant it in the right spot.

Either way good luck to ya, I'll be following the thread to see what you do!

Hi Green,
May I ask what you decided? We have a concrete border on one side and a concrete/block wall on the other side. We planted Nigra, Chinese Temple and All Gold. We have Oldhamii in a giant planter as a specimen rather than a screen, although it does a good job at screening the 2 story house behind us on one side.

We will have to be thinning a bunch but we're planning to eat it once it's to the desired height/width. We plan to cut the old, smaller growth out and then rhizome prune/cut new shoots and eat them.