It could be too much, or even too little, water during shooting.

If we get a lot of rain during the shoot growth period, the shoots will end up looking like the one in your picture.

Too little water can do the same, but is less likely.

If healthy leaves are falling off, you should be able to see if something chewed them off such as cut ants.

The mealy bugs are unsightly, and some of my bamboos get them real bad, but they have never been a problem to any of my plants.

Kt

I agree with kentuck...my first thought was a watering problem. You may want to get one of those $10 moisture meters at one of the big box stores and monitor to see if you have too much moisture. Also, have you had a colder than normal winter? Oldhamii is hardy to about 20F, and exposure to that temperature -- even for 24 hours -- could kill it; at temps above that, but below freezing, you could see serious aboveground damage. A distant third is the possibility of voles: they like to eat rhizomes and the plant gets sicker and sicker until it falls over. The mealy bugs are not the cause of this problem.

Be assured that you didn't provide too much info: this is somewhat baffling and the main cause is not obvious.

I don't know the effects of various herbicides (or gasoline or kerosene) on bamboo, but is there possibility your bamboo could have been poisoned by a neighbor? I've had some experience with over-the-fence neighbors spraying other plants and killing most of the tops out; interesting that your problem starts about fence height...

Bamboo is notoriously hard to kill, which is why getting rid of it by any means is such a challenge. I have never known of anyone to have success eradicating it with herbicides. I'm not totally discounting kevlar's suggestion, since someone could have tried to whack it with something...I'm just not sure what that something could be. From what I have heard, herbicide must be used in such large volumes to damage the bamboo that damage to adjacent plants/grass would likely be seen.

Thank you all for your insights. My neighbor doesn't really like the bamboo and he's cut anything that comes over onto his side. I've wondered about him using something, but think and hope these problems are something else. I've included a pic of most of the bamboo screen as it looks today. It used to cover the house completely. The other thing that is perplexing is that green leaves and their stems are falling off. (I'll include a photo). I looked up cut ants and we don't have them here, nor have I seen anything like that happen. We have squirrels, crows and I'm sure rats. Would they have any reason to cut bamboo?

This is a typical sprig of what's dropping. Many brown leaves also fall, but I think that is more or less the cycle of the plant. (helped along unfortunately by mealy bugs?)

view 2 of fallen leaves/stems

This is another view of the stunted culms that stop growing. When this happens, there is a black spot or shadow that seems to happen before that part dies. That's why I wonder if it's a pest.

This post was edited by andian on Sun, Feb 3, 13 at 14:38

view 3 stunted culms side view

This post was edited by andian on Sun, Feb 3, 13 at 17:11

Might as well show all my "dirty laundry". These are what I think are the mealy bugs and also shows the many leafless twigs.

This post was edited by andian on Sun, Feb 3, 13 at 14:37

No new ideas from me, other than to say that this is not a critter problem and not an insect problem.

What is the tree in front of the bamboo with dead leaves on it? Is that normal for that plant too?

I will get leaves that fall sometimes but not the limbs with it unless we had high winds.

Are you sure that you Oldhamii? It looks a little different than mine.

I doubt too, that this is a varmint or insect problem, sounds more like a water problem or maybe ground ph problem. Have you used any fertilizers recently or maybe the neighbour dumped salt water on the ground on his side of the fence? If so, you will see damaged grass and other plants, within a short distance and they will also show damage as Kudzu stated.

Kt

The tree in front is deciduous and is called a Koelreuteria paniculata or goldenrain tree. Not its most beautiful time of the year, but its normal for it to lose its leaves completely now.

As for being sure it's Oldhamii, I can only say I'm sure the nursery told me it was. I've often thought that the branches seemed so much longer and willowy than others.

The more feedback and internet searches, I'm beginning to wonder if poor watering (too much or too little), and/or not fertilizing correctly is the ultimate problem that has allowed pests and problems to take hold. There was also a scale that was starting to show up too. Almost the Murphy's Law of bamboo farming here.

I also remember that I sprayed the bamboo with dawn dish detergent in the summer in hopes of controlling mealy bugs and perhaps that is what kudzu9 is guessing.

Anyone have ideas on using dish soap as an insecticide and does anyone have knowledge of a decent insecticide to put in the soil to control mealy bugs without compromising the plant any further.

And thank you everyone for your input.

The reality with bamboo is that there is little that troubles it, and the approach to problems is much simpler than most other plants. The worst infestation problem is bamboo mites, but they only make the leaves look mottled, without threatening the health of the plant. There just aren't any pests that do damage like you have, and the dish detergent is a non-issue: it's a harmless, standard way to deal with aphids and the like. The problem is most likely some water or soil problem...not some mysterious malady that will respond to chemical treatment.

Thanks kudzu9, I'll take that info (and the others') to heart. I thought I'd add a pic of my bamboo from August 2009 during it's happier times. Hoping to get them all back to good health.