Some bamboo tend to have more closely spaced culms than others...it's just hereditary. Having said that, however, I have had some bamboo species that spread out more in some locations than others. I attribute this to amount of light and quality of soil, but I can't say for sure.

clumpers clump, some clumpers clump less closely, are called open clumpers.

runners run, and have in general their culms much more separated than clumpers.

culture, environment counts. soil, temperature, moisture influence clumping/running behavior.

There are always exceptions. :)

And I would add that summer heat makes a big difference as well, and can negate genetic tendencies. Areas with climates moderated by oceans, to the extent that summers remain quite cool - 60's & 70's not uncommon for highs as opposed to the humid 80's & 90's we have from June through September here in Indiana , is an environmental factor that make runners much tamer and more tightly spaced.

Check out Taming the Dragon, the new book by Paul Whittaker, an English bamboo nurseryman. England, although relatively cold in winter does not get as cold as we do in Indiana but their summers are significantly cooler, and the extremely modest spread rate he lists for his running bamboo due to their moderate summers is inconceivable to me.

To anyone in the PNW, how common is it to find out of control groves of bamboo? I assume it happens but how common is it?

hoosier52-
Insightful observations and an interesting question. I've rarely seen bamboo out-of-control around here, even though we're Zone 8 in the Seattle area and we don't get any dieback, except for those trying to grow tropical clumpers outdoors. I'm sure there must be some bamboo going nuts around here, but I have yet to see it.

I've been on two digs here where the folks had lost control, but it was modest compared to some of the pictures I've seen posted here. One was a backyard of pretty dense P. japonica that occupied an area about 10' X 20' and had gone under a 2' high cinder block wall on the property line and invaded about 5'-10' into the neighbor's yard. The owner had let the original japonica go for over 10 years without doing anything to try to control it. A 6-person work party cleared much of this out in about 4 hours. I was also on a dig to remove some Ph. nigra from a guy's backyard about 100 miles south of here. He had planted 3 plants about 7 years before and it was now a grove about 10' X 20'. It was next to his huge koi pond without a barrier and the rhizomes had come up under the liner and pierced it, so he was losing water and needed it dug out. He was in a location that was some distance from the coast here and his micro-climate had somewhat colder winters and warmer summers.
I have dug out a number of bamboo around here where peole thought they had clumpers, but they were really tightly spaced runners. That's not to say runners don't run around here. The record I know of is a S. fastuosa runner that came up 30' from the original plant. And I had 13 rhizomes radiating from one of my vivax this summer, but it's easily manageable with rhizome pruning. I still maintain rhizome pruning works wherever you are, but it may just require a little more vigilance elsewhere.

Interesting on the Fastuosa as I frequent a couple of UK garden lists and Fastuosa is one of the more aggressive runners there. My other Semiarundinarias have been quite vagabond but not the Fastuosa. I'm beginning to think that I have a weak plant in it. The Fastuosa Viridis has been way more vigorous.

Anyway, it sounds like Fastuosa is perhaps less impacted by cooler summers than Phyllostachys, in terms of spread.

In my area there is a fair amount of bamboo being grown and it is almost always Yellow Groove. About 5 years ago when we bought this place I ran a classified ad in the local food co-op's newsletter: "Will help to get your bamboo grove back under control in exchange for the plants". I had way more responses than I could deal with and all of the dig sites were WAY, WAY out of control and I did not really make a dent in them - too big of a job and these were groves that had never been fed or watered. Now I have more of it than I want and I've been digging some out and dragging it into the woods to let it die, out of sight. BTW, I checked out some clumps that have been out of the ground for weeks and they did not even have leaf curl and some had new rhizome growth!

hoosier,

Too bad you don't have the time or energy to take those that you remove and plant them at random spots all over the countryside. Would be cool to see what becomes of it.

I'm afraid that it would only serve to 'enhance' the bad reputation that bamboo has. Most people do not groom their groves even after years of serious top kill, therefore they not only run far they also look pretty shabby. Picture a bamboo thicket with lots of ugly dead culms and it makes it hard to convince people of its beauty.

Here in the great midwest, it is common to find 'U-pick' strawberry/raspberry farms where you go into the field and pick you own. What do you think about a 'U-dig' Yellow Groove farm??

Makes me remember the Black Bamboo I dug up when a restaurant was changing owners and the new owner didn't want the bamboo because it was invading the patio & coming up through the brick. Some of the boo brought home recovered, but one root ball, which had a few fresh leaves coming out of it, was obviously all played out, so I tossed it aside. It went on living above ground for 5 months with no watering, excepting the ocassional rain. Day before yesterday I root pruned my Yellow Crookstem. The longest runner was 39" (I just measured it). That was scary! Let's say I die and nobody knows how to care for this place (10 varieties now planted). In 3 years it could begin to take over. Did read somewhere that Yellow Crookstem is one of the most aggresive of the yellow culm bamboo. Is anybody else standing somewhere between respect and abject fear?

I have found running bamboo to run quite quickly and quite far in our PNW climate. The summers are relatively cool but there are nice long days and an excellent, long growing season. The big thing here is that there is little rain in the summer, and that will severely effect the rate of spread. I've seen many running bamboos that hardly go anywhere because the soil is hard and dry all summer. But when your water it in the summer, look out!

Because I believe that the watering has a lot to do with spread also, I have been surprised to read in Paul Whittaker's new book Taming the Dragon, that in his experience, bamboo only runs in dry conditions as it searches for moisture?

tcstoehr-
This is an interesting series of posts, and I'm now thinking...YMMV (your mileage may vary). At my other house I had a grove of Yellow Groove that slowly spread out to about 10' X 10" ...but that took over 30 years, and I never did anything to control it. Last year, I got the most growth out of it ever after I limbed up some tall firs and it got more sun. This summer I did a lot of watering, and got some runners to run, while others 3' away stayed tightly bunched. Since you're in Portland and I'm in Seattle, our climates are pretty similar. The mystery continues...

As a bamboo grower in the UK , I find it hard to belive the amount of rhizome growth the Phyllostachys can put on in the USA, here they tend to be clumpers with compact rootstocks. My Ph. nigra, after 6 years in the ground, is a clump around 18 inches and 12 foot tall, despite manure and all the water it needs.

The other side of the coin, is that barriers whilst not rec for Phyllostachys are needed for Yushania and some chusquea.

The short growing season I think is the main cause for Phyllostachys not running, last frost usually end of May/early June, and already had ground frost last week. Dosn't leave much time between shooting and growing those rhizomes.

When it comes to Paul W's book, he is growing bamboo in a very hard climate, very diffrent to most of the UK which is fairly wet, the winter are cold ( for the UK ) the summers are cold and it dosn't rain much ( pos 20/ 25 inches a year) and he's prepared to wait years for a plant to mature, I'd rather water and feed and get quicker results.

Not sure if the newer Borinds/ Yunnan / KR / A / collection stuff is growing over you're way but there's some great stuff out there, some of thr newer ones are in big demand here in the UK, cold hardy (-18c) clumpers, blue and with a near 3 inch culm size when mature. These new plants should outgrow any Phyllostachys in the UK.

"cold hardy (-18c) clumpers, blue and with a near 3 inch culm
size when mature."

what's that one? Borinda boliana?

You can also root prune a running bamboo several times during its rhizome extension season in late summer to force it to assume a clumping habit. I've used this method to create Pseudosasa amabilis, Phyllostachys edulis, and P. nigra bory clumps. I use the 'big blue shovel" to cut a ring 3 inches outside of the outermost culms once in Aug and again in Oct. Under this regime, bory has been slower at increasing in size than it would be if allowed to run, but amabilis and edulis has been increasing in height at the same rate as their running equivalents. I look forward to seeing a moso clump with 5" diam culms in about 7 years.

WOW.. what a interesting answers and great chat in this thread, well i was asking that because I found some boos to ask for cutting or maybe to dig one of them, but I've seen that mayority of the ones I found grew pretty much clump from each other and as someone here said, is kind of difficult to see the beauty of a bamboo if it have all the grove with dead culms and all of them clumped.. and I was asking to myself is that was a their normal behavior for that type of boo or it was cuz they were never pruned or maintenanced in any way

Borinda papyrifera, is the one , listed as growing to 6 cm and up to 3600m , old culms said to survive -18.

There are no mature plants in the Uk yet, but growth is pretty rapid, no winter damage here but with lows of only -6c it's not a fair test.

Three years in the ground.

{{gwi:423857}}

Borinda papyrifera

makj-
That's a beautiful bamboo. What's the expected height? (I presume the 3600m you referred to is an elevation!)

Hi, yes , I ment to say 6cm culm/ 8/10m (30') and found growing at 3600m Alt, would be quite scary if grew to my orignal est !

I'd also like to mention that a lot of the newer stuff seems to be growing larger than the Chinese descriptions, some like Yunnan 4( no proper name ) is now 12m tall and still growing, this is nearly twice as high as the orignal plants. So final height is really a guess.

Cheers.

Makj, are there any UK distributors of the B. papyrifera yet?

Beautiful picture Makj...

Beautiful speciman Makj.

Anyone know how this would fair in Florida?

I lost a Ch. foliosa to TX heat, even in the shade and well watered.

I also have a Pl. pymaeus in full shade, but it's growing about the size of clover, a little more pygmy than I was expecting.

I'd love to try a Borinda boliana, but worry about the San Antonio mid-summer heat, even in partial shade. Worse, it's a mountain bamboo, and I ain't got no mountain. :)

Bambusa Multiplex 'Alphonse Karr' seems to grow with a very high level of culm density. Although in this area it seems to spread out to a similar extent to the clumpers with more spaced out culms it could be due to the fact that it the temperature is more suitable to it. In a warmer climate the larger species with less cold tolerance might spread out farther.

Bambusa Chungii seems to have somewhat spaced out culms as does Bambusa Oldhamii (once it develops substantially).