Bamboo drought tolerance

[Mike,Marietta,SC,z8a]

Last summer's extreme drought in the Southeast was a good opportunity to gage the drought tolerance of various bamboo species. Based on last summer's midsummer shooters and the shooting results this spring. Last summer/fall, Borinda boliana, Fargesia nitida, and Bambusa emiensis (species and cultivars) didn't shoot, although Bambusa multiplex and its cultivars shooted normally. This spring, moso produced no shoots except in locations where rain flow was naturally concentrated. Fargesia dracocephala rufa, F. robusta, Chusquea culeou, Hibanobambusa tranquillens shiroshima, Phyllostachys elegans, P. makinoi, P. aurea koi, P. auroesulcata spectabilis, P nigra (and bory), Semiarundinaria fastuosa, ans S. yashedaka kimmei all produced normal numbers of shoots. Sasa kurilensis shimofuri and Bashania fargesii produced a moderate number of shoots. I don't know yet about P. dulcis, since around here it normally doesn't start shooting until late May. The running bamboos that I have root pruned to force them to assume a clumping form also had few to no shoots this spring.

[johnfe]

Interesting data... I was wondering about this process just today... is it because the lack of rainfall last summer caused lower leaf production which in turn means there's less synthesis over the year, thus less stored to power the shoot production this spring?

[Mike,Marietta,SC,z8a]

With moso during a drought, especially when the relative humidity drops as well, the leaves will curl for extended periods of time during sunny days. When the leaves are curled, photosynthesis is mostly shut down, so the bamboo isn't storing energy to be used for making next year's shoots. Also the bamboo will pruduce fewer leaves and shed some of the leaves it already has when it is drought stressed.

[johnfe]

Aha! So that's why it's important to water when leaf curl starts...
Thanks for your info. Hope to see you in Asheville.

[Roy]

Aha! So that's why it's important to water when leaf curl starts...
Thanks for your info. Hope to see you in Asheville.

Leaf curl does not always means that the soil is dry and the plant needs water. In the middle of the Summer time, here in Tampa, Florida, we can get 2 inches of rain one afternoon and I can see leaf curl the the next day. (I'm not talking about where the leaves are tightly curled and look like a pointed stick) I view the leaf curl issue as one in which the leaves are giving off more moisture, based upon temperature, humidity, and sometimes wind, than the roots can uptake. When more moisture is going out than is taken up on the root end, then the leaves curl slightly to reduce the amount of moisture being given off to try and achieve the correct balance or ratio. Of course, the more extreme the difference between the amount of moisture given off and the amount of moisture being taken up by the plant, then the more stress on the plant which could lead to irreversible damage to the plant.

[johnfe]

So I guess you mean that's happening with well-established plants... what about with divisions recently set out? I always thought you had to trim the culm down to just a few leaves, but lately have seen people saying you could leave the whole culm, just watch for leaf curl and water if it got bad - though I tried that with a P. nigra division and lost 2 of 3 culms, and now it's just putting up two tiny whip shoots. This black was in serious decline already, and was moving part of it to see if it did better in another location, so not really a good test, but I'm confused about the whole issue now.

[Roy]

So I guess you mean that's happening with well-established plants... what about with divisions recently set out? I always thought you had to trim the culm down to just a few leaves, but lately have seen people saying you could leave the whole culm, just watch for leaf curl and water if it got bad - though I tried that with a P. nigra division and lost 2 of 3 culms, and now it's just putting up two tiny whip shoots. This black was in serious decline already, and was moving part of it to see if it did better in another location, so not really a good test, but I'm confused about the whole issue now.

johnfe,

Sorry for the added confusion. I was talking about established plants and I also think Mike was also. He was talking about temperate bamboos and I was talking about tropical bamboos. I think the information applies to both types.

As far as newly transplanted bamboo, then that's another story. I would say that on almost any transplanted/freshly dug bamboo, a good topping will go a long way toward having a successful transplant. There are very few times that I don't top a transplanted bamboo and along with "no topping" comes a lot of extra care, time, and expense.

In general, my "non-topped" bamboos will take longer to put up a new shoot, a smaller number of shoots, but the shoots they do put up will be larger than topped ones. The topped ones will put up new shoots faster, have more shoots, but the shoots will be smaller.

My experience is with tropical bamboos. My limited and long ago experience with temperate bamboos leads me mostly to refrain from giving any advice on them.

[johnfe]

Thanks for your response - I appreciate your taking to time to answer questions from a novice! I have mostly temperate bamboos, but I do have a lot of Silverstripe, and I'm just beginning an experiment with a big clump of multiplex that I think is Alphonse Karr... I'm going to start a new topic on it I think... maybe you'll be interested.

[Roy]

Thanks for your response - I appreciate your taking to time to answer questions from a novice! I have mostly temperate bamboos, but I do have a lot of Silverstripe, and I'm just beginning an experiment with a big clump of multiplex that I think is Alphonse Karr... I'm going to start a new topic on it I think... maybe you'll be interested.

I never consider myself an expert. It leads to a closed mind and that's when you stop learning. When I think I really know something about a bamboo, that's when I start questioning what I think I know. I find out new things all the time about bamboo.

Bambusa multiplex 'Silverstripe'! My first bamboo. How does it take the cold weather in your area and how cold does it get in your area?

Some of my pictures from my backyard:

[johnfe]

I'm with you on that 'expert' thing, Roy! It's like the Zen master and the professor story... if the cup is full, no more will go in...

As for the Silverstripe, it does great here. It grows along my alley probably 30 yards, may have been here 30+ years. It shoots strongly in late June/early July. Here's a couple of shots of the largest culms in the clump.





We have fairly cold winters but rarely freezes, maybe two or three days of hard freeze any given winter, so sometimes I've been able to winter over pepper plants with lots of pine straw. We're only 40 miles from the coast, so that moderates it a bit.

Here's a clump I transplanted to the front of our lot about 1999:



So it does well here. These are probably here due to the Bamboo Farm in Savannah - I think they (USDA) were encouraging farmers to plant bamboo back when this was farmland. There was Madake here 20 years ago when we moved in. It's doing well too! Of course I water it - not the Silverstripe. The Silverstripe would probably survive about anything that could happen around here... drought, development, meltdown of the Plant Hatch reactor... well, that might get it.