Floppy phyllostachys

[tstoehr]

Over several years I've been trying to grow some nice, upright spreading bamboo to shade west side of my house from hot afternoon sun. It would also give me something nice to look at out the window there.
I started with P. Bambusoides Allgold. It flopped over and had a ton of aphid problems so after a couple years I ripped it out. I foolishly tried P. Nigra after that. In this their third year the new shoots rose up like champions, but eventually they all went horizontal, some actually laying their tops on the ground. And that was after selecting the most upright shoots and cutting the others off. I'm in the process of removing the P. Nigra.
I want something that will stand straight up. So I ran off to BambooGarden and got some P. Heteroclada (straightstem). However, it seems to me that it will suffer the same fate. I have P. Nigra Henon and P. Dulcis growing up on my hillside in a more "wild" setting and they haven't flopped over. So I have to think there's something about the growing conditions on the west side of my house that encourages Phyllostachys to lean over.
There's enough sunshine, especially after noon. There's adequate moisture all year round, but never soggy at all. Yet always moist. Could too much moisture or nitrogen be a problem? I have used fertilizers, but only sparingly. Perhaps none whatsoever is the best policy. I have mulched with lawn clippings, maybe that adds too much Nitrogen.
So... to sum it up... why won't my Phyllostachys stand up straight? Any suggestions?

[ghmerrill]

Tim,

it sounds like you have not given the plants the time in the ground to mature, and untill then, the culms will not be as upright. the bambusoides should have been OK for what you wanted it for, and with some age to it, would have been great for shade as well. P. nigra is not one to put where vertical mass is needed, as it does droop more. P. nigra henon is more upright, but that is comparing the oldest groves of plain nigra, which never seem to get to much size, with the oldest grove of Henon I have seen, which was monster size and very upright at that point.
as an aside, you realize that if you plant bamboo along that side of your house to shade from the summer sun, it will also shade the winter sunlight? sometimes areas like that are best with some deciduous trees.... then you can plant some nice groundcover boos under them!

just a thought!

[needmore]

Tim, as you probably already know it can take a few years for many of the Phyllostachys to straighten up, so I tend to notice those that do so earlier. My Straightstem is still floppy at around 10-12 feet tall and 3-4 years. The Propinqua Beijing I obtained from Jim Bonner has struck me as quite upright, early on. Spectabilis also seems to stand up fairly early on, as does Dulcis. Atrovaginata does well after about 3 years or so.

I find that in addition to overfeeding, thinning to soon after new culms have come up, another floppy contributor is loose soil (not enough clay) and or soil that is undermined by moles/voles/shrews etc.

[tstoehr]

What? Your Straightstem bamboo is floppy after 4 years? I'm hosed.
I have grown Bory, Dulcis and Henon in other areas without such flopping-over problems. Maybe I should cut some Dulcis divisions and try those. No... I really want to try the Heteroclada, it does seem quite straight and upright at the Bamboo Garden Nursery. I think though that I will cut back on the watering and give *no* fertilzer and only a brown mulch. And wait a few more years... sigh.
It's not so much that the culms bend directly out of the ground, but rather that they bend along their whole length. One culm in particular that was very good and straight-up last year, this year bent over 90 degrees at mid-culm while still pointing straight up at ground level.

[va_highlander]

It's not so much that the culms bend directly out of the ground, but rather that they bend along their whole length. One culm in particular that was very good and straight-up last year, this year bent over 90 degrees at mid-culm while still pointing straight up at ground level.

What you describe sounds typical for an immature grove.

I planted a start of P nigra in spring a little more than two years ago, just as the plant was starting to shoot. Max height that first shooting season might have been four feet, before those culms leafed-out and arched to the ground.

A year later, the tallest new culms were eight to ten feet in height, before again leafing-out and bending nearly to the ground. This season, the smallest new culms are still almost horizontal, but there are only two or three of those. The rest are around twelve to fifteen feet in height and more-or-less verticle for the first six. The tops arch in that characteristic P nigra sort of way, but even when it rains now they don't sag all the way to the ground.

When I planted this thing, I amended and top-dressed the soil with about five galllons of composted manure and haven't fertilized since. I mulched with a thick layer of dead leaves, to insulate the root mass during its first winter, but didn't bother last fall. I watered about once a week during the first summer, since then only when it gets really dry. Aside from rhizome pruning, I have left it to grow as it will, in the hope that the greater the leaf mass, the faster it will spread and gain in height. Seems successful so far.

I don't know whether my method has helped or not, but given the trend of the past two years, I expect next-year's culms to be taller and as vertical as they were this season, if not more so - barring top-kill this winter, of course. I will probably start culling the runts and floppies next winter.

[needmore]

I need to correct my earlier post, I was answering as though you had Solidstem rather than Straightstem - my Straightstem is 6 years in the ground and still not 6 feet tall, so still very floppy. This is the slowest Phyllostachys I have in terms of sizing up and cold temps are not the issue, it is just plain slow for me. The parent grove is mature and very vertical but it must take a VERY long time to mature, Bissetii in the same time and same conditions is over 30 feet, several others in the ground less have sized up way faster. The Solidstem has been faster.