A 12 foot ditch seems rather excessive for containing bamboo. 3' or maybe 4' should be plenty (wide and deep) and if you can create a ditch around the bamboo that holds water, presto ... bamboo won't grow thru water. Your bamboo will live contained on it's own island.

Cheers, Barrie.

OOps. I meant 12 inches. I don't want to dig a moat, or a pond.

Leslie

Leslie,

I have a small ditch around my Nigra for a couple of years now, which I watch in Oct, Nov. So far so good. But I too worry that the plant will simply send the rhizomes deeper. To fool the plant, I actually fill in the ditch with manure, then transfer the manure up onto the plant when I am patrol with my shovel. I reckon the plant might exist (in nature) on a hill, and will certainly seek soil and send the roots where the soil is. What to do when I'm 80, isn't a question I can contend with now, even though I'm already 63. I realize this post isn't so much an answer as a commiseration. Good luck.

leslie-
I like to spend my energy efficiently, and I've never been a big fan of barriers and ditches. I plant my bamboo in a slight mound (4"-6") and rhizome prune once a year. so far none of my 40+ runners have made a getaway.

kudzu,
This is probably a dumb question (sorry) - are your mounds 4'-6' high, or wide?

Rhizome pruning around a big grove sounds very difficult to me. My soil is hard. This weekend I was planting shrubs & trees, and many times I set the shovel down, jumped on it hard (just stomping with my foot didn't do anything), and the darn thing bounced off the dirt. It was that hard. When you plant in a mound, do you have to dig down to the rhizomes? Or are they on the surface?

I think the soil inside the grove will be much better. I've only been here 1.5 years, but I can see already that wherever I've put a thick layer of grass clippings as mulch, the ground is much improved, and the plants grow much better.

Leslie

Not a dumb question. My mounds are 4"-6" high and about 3' in diameter. It seems to help keep the rhizomes nearer the surface. Of course, if you want a large, continuous grove, then you would want the plants to expand beyond a mound. If you've got really hard soil, the rhizomes are probably going to stay near the surface, and you don't really need to do the whole circumference with a shovel every year...you can usually figure out where a wayward rhizome has come from, and concentrate on severing that connection. I just think it will be many years before you really need to worry about rhizome pruning at all, and I wanted to save you from a bunch of unnecessary ditching now.

Kudzu - that does sound good. I will use your idea for mounds - as I've searched for bamboos, I've found several that I wanted a grove of, but others where I wanted just a patch - what you've described as a mound.

Thank you for sparing my back from the unnecessary ditch digging! I feel reassured about the whole "bamboo control" process.

Leslie

I do what kudzu9 does, and it works. You just have to be diligent each shooting season and watch for unwanted shoots.

> My mounds are 4"-6" high and about 3' in diameter.

Wow... just 10 square feet per plant. Do you feel this severely restricts the maximum culm size? Or just minimally? Or what? I have a Bory growing where I've got 200 square feet allocated, and I sometimes wonder if that's enough to let it size up to its potential.

tcstoehr-
It doesn't keep them from growing beyond the mound if I let them...I actually have over an acre, but I just want to keep some runners to a clump shape and the mound reminds me of where to chop if I want to. I don't think that keeping a runner on a small plot has any significant effect on culm size, as long as it's sending up culms only outside that area and they're the ones that get chopped. I've seen lots of bamboo in pots and large containers that send up nice big culms. I'd be interested to hear, though, if there are other opinions on whether maximizing culm size depends on letting it go "free range."

Since we're on the subject, how hard is it to prune a wayward rhizome? Will a shovel be sufficient, or do I need a saw? And if I do manage a moso grove (and I really want one) ... well, what would it take to prune one of THOSE rhizomes?

And pruning the older growth of black bamboo? It's only supposed to be about 2 inches diameter, so I don't suppose that's too bad. But what about the moso? A chainsaw? And what do you do with the old culms, once they're cut?

Leslie

Leslie,

I don't know how hard it is to rhizome prune yet since my bamboo is just starting, but this is the method I will use after alot of reading around here and espically Kudzu's posts.

AS for getting rid of Moso culms you can use them for fences crafts give them away on freecycle. I don't think you will have a problem using them or giving them away.

I take two implements of desctruction with me for root pruning. A sharp, flat-nosed shovel for methodically slicing along the perimeter, and a pair of heavy loppers. Usually the shovel goes right thru the rhizomes, but sometime I need to nip them with the loppers after the shovel bounces off. I've found the rhizomes are considerably smaller and more uniform in diameter than the culms, but also solid to the core. They're tough as nails when they've matured, but nothing your tree-pruning loppers can't handle.

My gut feeling is that the larger the grove, the larger the culms will get. Up to a point of course, that is, you're not going to get 12" culms just because your grove occupies 10 acres. But how much area does a runner need to reach its full culm height and diameter potential in the given local growing conditions? I once asked a fellow at the Bamboo Garden Nursery (Oregon) if 200 square feet was enought to "max out" a Ph. Nigra Bory, and his opinion was that it was not quite enough.

Whenever I hear about mega-thick culms of bamboo, it is always in old forests (not groves) somehwere in the far east or India. I am guessing that age is a big factor in sizing up really big. While Vivax may get to 5 inches in just a few years, would it get to 10 inches after 50 years?

Here is a photo of a young plant's rhizome. A mature grove rhizome can be four times the thickness of that, and part of a tangled, dense network.

Here is a link that might be useful: rhizome

i root prune in winter,after a couple days of hard rain.then just go around the grove with a shovel.it is a job,but not too difficult.