Limp floppy black bamboo canes

[wattzat]

I've divided a large container of black bamboo and some of the smaller shoots and canes which have emerged are not stiff; one grew 3 feet tall, developed leaves and has totally flopped over. Other pots are mixed - some hard, some soft. Some new shoots in a container that is choked with roots [but I haven't divided yet] are as tall as they should be, but are also thin and soft near the top.

The only difference from other years is that the containers are now on an apt balcony as opposed to the containers themselves being in full sun for a part of the day.

Also, I used a potting mixture with osmocote ("Secret" is the brand here on Vancouver Island)

I'd be grateful if someone can give me some insight into why this is happening.

[sasa fool]

I generally see this when I'm propagating bare rhizomes - the shoots emerge, leaf out and then flop over. Right or wrong, I've decided that it is a cause of too much moisture in the container and/or lack of rhizome energy. Keeping them drier seems to reduce incidence of this, not sure if it is your situation though.

[Mark Meckes]

Yep, a division will often produce tillering floppy shoots, especially when done near or during the growing season.
These are reactionary sprouts growing from the rhizome buds in response to the plant being divided.
Shoots that emerge later from greater depths have more earth to anchor them. Often with a potted division, shoots from rhizomes near the soil surface will also grow out at an angle and can have the appearance of an extension of a rhizome rather than a true shoot.

Phyllostachys nigra is also known to sometimes having excessively 'gracefully arching culms' ... ie, the tops can arch and bend right over.

I have planted black bamboo at various places around our property, and though I don't mind having to occasionally duck under overhanging culms or being slapped in the face with a wet kiss from a sodden branch along pathways ... enough is enough.
So I tie back or stake some culms or remove one of each of the two alternating branches at each node up the culm to reduce the leaf weight.

Nowdays, where I've learnt from experience where overhanging culms may become problematic, I also employ preventative measures early on in a new shoot's life.
When the shoot has risen to about 2/3rds of it's height I snip or pull the top 1/3 off. They seem to grow out more naturally when done early this way.

Also if I want to make them even more 'tight and bushy', when the side branches of the new shoot begins to unfurl, I pull off the growing tips like this:
http://www.bamboocraft.net/bamboo/data/527/thumbs/PnigAuTX030415-472.JPG (http://www.bamboocraft.net/bamboo/showphoto.php?photo=3225) http://www.bamboocraft.net/bamboo/data/527/thumbs/PnigAuTX030415-474.jpg (http://www.bamboocraft.net/bamboo/showphoto.php?photo=3224)

You can still trim back bamboo after it leafs out, but it looks less hacked if you take the pruner blade back to the severing point but avoid cutting off the leaves growing near that point.
Hard to explain. If you try it you should see what I mean.

Mark

[wattzat]

I generally see this when I'm propagating bare rhizomes - the shoots emerge, leaf out and then flop over. Right or wrong, I've decided that it is a cause of too much moisture in the container and/or lack of rhizome energy. Keeping them drier seems to reduce incidence of this, not sure if it is your situation though.

Thanks for responding - it may well be both; I was pretty brutal when dividing the clump. Perhaps I'll just cut one pot down and see what happens, see if the roots put out larger culms next year. And with the container I didn't divide, perhaps the soil is exhausted as well causing poor output.

[wattzat]

Yep, a division will often produce tillering floppy shoots, especially when done near or during the growing season.
These are reactionary sprouts growing from the rhizome buds in response to the plant being divided.
Shoots that emerge later from greater depths have more earth to anchor them. Often with a potted division, shoots from rhizomes near the soil surface will also grow out at an angle and can have the appearance of an extension of a rhizome rather than a true shoot.

You've described exactly what happened: I left the division too late because of a move, and yes, these shoots seem to be coming from near the surface. So I think I'll do as you have suggested and pull out the tips of the newly emerging ones. As for the container that didn't get divided, I'll wait til December, then take a chainsaw to it :)

There certainly is a lot of splendid arching going on as the branches develop more leaves! Love this bamboo. Thanks for your amazing pictures.

wattzat

[Mark Meckes]

Yes I do culmcur watzat, this is an attractive bamboo, and it's embracing habit just shows that it loves to be loved. :)

I've planted extra patches of this boo amongst other boos and under filtered shade of tree canopies because here in Texas they seem to prefer to have some shade during the excruciatingly hot summer months.
I do have one planting in a very sunny location which develops culms that are vibrantly speckled.

I enjoy watching the culms change from a velvety green to speckled browns during their first year, then to deeper shades of brown and black as they age.
As they age further they can develop a white coating on the surface which can upon harvest/drying be removed by heat.
In fact my wife was just this evening using an electric heat gun and paste wax to polish up some of our harvest, and she turns smaller diameter pieces into beads for jewelry.
I've been thinking of polishing some while they grow to see how they turn out at harvest.
I know someone else who specifically likes to grow this bamboo in rootbound conditions, to harvest select contorted rhizomes (which also turn black) for use in jewelry making, broaches etc.

Mark

[sasa fool]

I am a little confused by the flopping culms you are having, I was originally thinking that you meant they were flopping over as in collapsing and soon rotting - that is what I was thinking you meant when I responded with the too much moisture/lack of rhizome energy. It sounds like instead you are seeing what Mark describes, culms that don't die off, just are not upright which is indeed a different situation - I think you should ignore my earlier reply then!

[wattzat]

sasa fool, they could well still collapse and rot; I have no way of knowing, but it looks like they're ok so far. Thanks for your insight!

I had scoured the web for answers but couldn't find the right search words, I guess. Ultimately, I ended up here and am very happy with the quick help I got! Also, I am thoroughly enjoying all the photos and posts I have read so far :) Thanks again.