Bamboo stops growing after several feet

andianFebruary 2, 2013

My bambusa old hamii is having a rough season. I see 3 separate problems and am hoping someone can shed light on them to help me remedy.

1. Some of the shoots spring up quickly and look perfect until they reach a certain height usually about 6 to 10 feet, then the culms seem to pancake in on themselves (almost like a telescope that gets closed up). There seems to be a black spot on the surface and it rots inside at that point. Everything under the rotten area seems healthy (but short).

2. Healthy leave shoots are falling off, almost as if something is chewing them off. This bamboo screen that I planted once hid the neighbors house, but now with so many leaves falling the house is in plain sight and the bamboo looks miserable.

3. I see evidence of mealy bugs. It seems I've had these awhile and hasn't been too much of a concern. Now however they seem rampant. I've sprayed them using dawn dishwashing liquid several times during the summer. I've hesitated to put any insecticide on the leaves/stalks as I have so many hummingbirds and other small birds in the area. I'm okay to use a systemic insecticide, but have yet to do that. Any suggestions?

Some background on the bamboo: Planted about 25 containers of 5-6 foot stalks approximately 5 years ago. Have grown wonderfully until recently. Live in Hermosa Beach, California. Has mostly morning sun, but has had less as the deciduous tree in front of it grows taller. Use soaker hose watering every day for about an hour (except this winter) and have been letting what rain we have water it. Prior to this year, I've just left the soaker on most of the year and all was well. I fertilize it about every 3 months. Keep a layer of its own leaves as mulch. Put home grown compost on in the spring.

I know this is a lot, but I've yet to find any information on 2 of the 3 of these problems.

Thank you for reporting this comment. Undo

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.


    Bookmark   February 2, 2013 at 7:59PM
Thank you for reporting this comment. Undo
kudzu9(Zone 8a - PNW)

I agree with 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.

    Bookmark   February 2, 2013 at 10:34PM
Thank you for reporting this comment. Undo

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...

    Bookmark   February 3, 2013 at 11:13AM
Thank you for reporting this comment. Undo
kudzu9(Zone 8a - PNW)

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.

    Bookmark   February 3, 2013 at 2:06PM
Thank you for reporting this comment. Undo

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?

    Bookmark   February 3, 2013 at 2:20PM
Thank you for reporting this comment. Undo

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?)

    Bookmark   February 3, 2013 at 2:24PM
Thank you for reporting this comment. Undo

view 2 of fallen leaves/stems

    Bookmark   February 3, 2013 at 2:25PM
Thank you for reporting this comment. Undo

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

    Bookmark   February 3, 2013 at 2:29PM
Thank you for reporting this comment. Undo

view 3 stunted culms side view

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

    Bookmark   February 3, 2013 at 2:30PM
Thank you for reporting this comment. Undo

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

    Bookmark   February 3, 2013 at 2:34PM
Thank you for reporting this comment. Undo
kudzu9(Zone 8a - PNW)

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

    Bookmark   February 3, 2013 at 2:51PM
Thank you for reporting this comment. Undo

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.


    Bookmark   February 3, 2013 at 3:55PM
Thank you for reporting this comment. Undo

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.

    Bookmark   February 3, 2013 at 5:54PM
Thank you for reporting this comment. Undo
kudzu9(Zone 8a - PNW)

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.

    Bookmark   February 3, 2013 at 6:19PM
Thank you for reporting this comment. Undo

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.

    Bookmark   February 3, 2013 at 6:43PM
Sign Up to comment
More Discussions
What's Wrong With My Bamboo?
Hey all, I'm a brand new member and this is my first...
argh neighbor
I live on six acres and we have a new neighbor. He...
Will remove unwanted bamboo in nc
Hey all, My team and I willing to remove a mature bamboo...
If selling bamboo - what to sell and how?
Greetings all! We have just aquired a home that has...
Using plastic container as barrier
Greetings, Do you think I can use plastic container...
Late Sound
People viewed this after searching for:
© 2015 Houzz Inc. Houzz® The new way to design your home™