To clear cut or not ?

[Matt W]

I haven't seen this kind of damage before. So the question is, is there any chance of re-leafing? Or should I just cut it all to the ground before shooting season.
More burned photos here https://mattsbamboo.shutterfly.com/476



Matt

[jpluddite]

I don't have an answer, but I'm in a similar situation.

Matt, are the culms dead? How old are your groves? What do they typically look like this time of year?

I have several culms that have 40%-70% of their leaves burned, but the bottom half of the culms (at least) are still alive. I imagine that many, but not all, of them will (partially) re-leaf.

Are you considering the impact on this year's shooting season of cutting those culms now or letting them re-leaf? Essentially, I'm concerned about how much energy my bamboo is going to divert into re-leafing versus pushing up new shoots. My groves are young--between 1 and 3 years old.

[Matt W]

This patch was started from a single plant in the summer of 09. No, this isn't typical. During the milder winters we have been having it stays green all year. I think it did top kill about the second year. But it recovered nicely. Yeah, I'm thinking about the same things. Plus once shooting starts it would be much harder to remove the ugly dead stuff without damage. It it kinda interesting looking now and shows the black culms nicely, but I think it will look rough when new culms start to form. Maybe removing 1/2 or 2/3 would be a good way to go? I saw in David's post that he has already bush-hogged some of his burned groves. I'm not sure how to tell if the culms are dead.

[stevelau1911]

I prefer to cut away the dead sections, or any section that seems to be afflicted to the point where leaf buds may struggle to emerge in order to improve the flow of energy in the culm, and expose more sunlight to the existing leaves. This way, the a lot of locked up energy which is going towards half dead parts can be allocated to new shoots as well as the other live buds on the same culm. I prefer the bamboo to not allocate energy to parts that would struggle to thrive.

Here's what I'm talking about.

Before


After


If leaf buds appear fried on a certain section while the culm still appears alive, I think it's best to cut off the branches and leave the culm section alone.


I like doing this for the aesthetics as well, but I believe this kind of pruning can help the bamboo in its overall health.



For the ones that are really top killed close to the ground, I think it would make sense to wait a few weeks later until it becomes more clear which sections are dead and what is still alive. For example, I think it would make sense to top these above their 2nd or 3rd node before shooting season to make room for more growth. This is my worst looking bamboo by the way.

[jd.]

Culms that still have a few green leaves remaining have a chance of growing new leaves. However, growth of new leaves may be weak on culms with extensive leaf damage.

Hopes aren't high for culms with total leaf kill. Completely cutting out such damaged bamboo before new shoots emerge may save time.

If some sections of the bamboo survived the winter with leaves alive and green, there may be little to no benefit from keeping the sections with dead leaves that suffered more damage.

[oobmab]

Ouch, Matt. It hurts to see that. Your nigra looks like mine. How did your YG do? Mine was barely touched. Since the cold weather we had, I've planted 40 clumps of YG (so far) to compensate for the damage done to my Jap Arrow bamboo. The Henon I got from you did fine until the second wave of subzero temps we had.

[jpluddite]

Steve,

Can you show us a close up picture of leaf buds--ones that are healthy, ones that are dead, and ones that are in between? That would be very helpful.

Usually, I don't like to use fertilizer, except compost or the like, but given this winter's disaster, I was wondering if applying Scott's Organic Choice Lawn fertilizer and/or Milorganite might help preserve this seasons shoots. My thinking is that the culms that are re-leafing are going to suck up a lot of nutrients that might otherwise help with the shoots. What are your thoughts?

[stevelau1911]

It's easier to tell once they start elongation, but ones that are blonde with 100% leaf burn are obviously dead. The ones that are questionable will have partially burned leaves, but may still leaf back out however that growth is likely very weak. I might be able to get photos although my micro setting is pretty weak so it will be a challenge. A lot of times these in between buds will have black on them as well as on the branch, and I will usually still cut these off too especially if I want the bamboo to invest as much energy as possible on the new shoots. I cut off a lot of these questionable buds on the top of that culm along the top of my greenhouse.

The completely live buds should be nice and glossy as they are filled with moisture and the leaves should still be green. Basically, all the remaining buds in the picture of the whole plant are definitely alive. This is about 80% more leaf mass than last spring so if this plant gets the signal to go all out and put all it's energy into shooting season, it should be even greater than that of last spring especially if there will be delayed shooting due to the weather.

[mountainbamboonut]

Steve, if the leaves on a particular culm are all totally fried, is there zero chance of that culm putting out new leaves in the future (dead)?

I have one small stand of megurochiku with 5 culms, 3 of which are last year's culms. It has only been in the ground for one season. The oldest and largest culm is totally fried like the ones picture by the OP of this thread. I was wondering the same thing if there is any benefit to removing this blonde culm or leaving it since there are only 5 total. Thanks for the advice.

[stevelau1911]

It depends on the species. For example, aureosulcatas tend to hold onto leaf buds despite leaf burn while atrovaginata and parvifolia tend to have branch/bud death whenever the leaves look fried.

I've never grown megurochiku, but I believe nigra is closer related to the aureosulcatas so there's a decent chance of re-leafing, but 100% leaf burn is a tough case. I guess you may need to just wait to see if leaf buds elongate. Another way to tell is to see if you can easily flick off the leaf buds to see if they still have juice flowing through them.

You may still get an upsize if your bamboo is very small. In terms of cutting stuff off, there's really only a benefit if the fried leaves are blocking sunlight, or blocking the energy flow to other branches and buds sort of like an un-pruned tree where a lot of energy gets locked up in unnecessary dead or partially dead parts. If most of the culms are top killed, there may be no point in doing what I showed in those pictures.

In a normal winter, tarping should be completely effective in protecting a small bamboo, and there are tons of ways you can still pamper a small plant to make a lot of progress even if it doesn't get any bigger this year.

[mountainbamboonut]

Thanks for the reply Steve. If there is no branching/leafing out (of the dead culm I mentioned) this summer then it is definitely dead, yes? In other words, can a fried culm make it through multiple growing seasons remaining blonde with no new foliage and then after 2 seasons re-leaf? I'd imagine if it appears dead through the growing season then it is in fact dead. Is there any merit to this or am I making things up?

[JWH]

I'd imagine if it appears dead through the growing season then it is in fact dead. Is there any merit to this or am I making things up?

Sounds right to me.

[dependable]

I was wondering if there is any energy still stored in culms that have killed leaves and buds. I read an article in most recent ABS journal by Michael Bell that indicated a lot of the plant energy for putting up new shoots is stored in culms, not just in root systems.

[stevelau1911]

Here's what I meant by partially dead. This section had a good amount of starch in it's culm, but the top part was hardy worth re-leafing and I believe it is better to cut those branches off, not the culm just so the energy can be diverted towards new shoots.



The culm seemed more interested in putting energy towards re-leafing rather than new culms in this situation.


Since so much energy was diverted toward repairing the original culm, very little was left for shooting season, and the only culm that emerged was hardly any bigger than that original culm. This new culm is the same culm as the before/after photos from the previous post.

[Alan_L]

The large dead culms can be left in place to help provide support for the new growth, so if it were me I probably wouldn't clear-cut, but I would thin.

I don't like to speculate on how much energy growing new leaves might steal from the shoots, as I have no idea if that actually happens or to what extent. For smaller plants I can understand the desire to try and manage them to maximize growth, but for a mature plant I'd rather just let the plant decide what it needs.

I'm fertilizing all the bamboos with Milorganite today.