Stopping select bamboo culms how?? pruned but they carry on!

[cordyman]

As you can see in the pics i'm pruning any new culms which are coming up under my kerbstone on the top of my wall, the problem is there still growing! Is this just temporary, or is there some kind of technique properly terminate a new culm ?

[Yorkshire Kris]

They grow from the top of the culm so cutting the tops off should stop them.

[simon]

They grow from the top of the culm so cutting the tops off should stop them.

I don't think that is quite true or at least not the full story. I have taken a broken-off juvenile culm and gradually peeled away the sheaths. Once removed, you can see all the nodes are closely packed together towards the top and are gradually further apart heading toward the bottom. This suggests that many of the internodes grow together but from the lower portion quickest and the culm expands like a concertina but biased towards the bottom first.

When a culm is a couple of feet tall it will consist of several fully grown internodes at the bottom and the top portion still having tightly packed nodes and the most growth activity will be about 2/3 up the culm. This gives the impression it is growing from the top. A very short culm, a few inches tall will still be growing at the base so any internodes left behind could continue to expand, so they need to be broken off very low down to avoid further growth. I always just snap the off at ground level which seems to do the job.

[Yorkshire Kris]

They grow from the top of the culm so cutting the tops off should stop them.

I don't think that is quite true or at least not the full story. I have taken a broken-off juvenile culm and gradually peeled away the sheaths. Once removed, you can see all the nodes are closely packed together towards the top and are gradually further apart heading toward the bottom. This suggests that many of the internodes grow together but from the lower portion quickest and the culm expands like a concertina but biased towards the bottom first.

When a culm is a couple of feet tall it will consist of several fully grown internodes at the bottom and the top portion still having tightly packed nodes and the most growth activity will be about 2/3 up the culm. This gives the impression it is growing from the top. A very short culm, a few inches tall will still be growing at the base so any internodes left behind could continue to expand, so they need to be broken off very low down to avoid further growth. I always just snap the off at ground level which seems to do the job.

[Yorkshire Kris]

They grow from the top of the culm so cutting the tops off should stop them.

I don't think that is quite true or at least not the full story. I have taken a broken-off juvenile culm and gradually peeled away the sheaths. Once removed, you can see all the nodes are closely packed together towards the top and are gradually further apart heading toward the bottom. This suggests that many of the internodes grow together but from the lower portion quickest and the culm expands like a concertina but biased towards the bottom first.

When a culm is a couple of feet tall it will consist of several fully grown internodes at the bottom and the top portion still having tightly packed nodes and the most growth activity will be about 2/3 up the culm. This gives the impression it is growing from the top. A very short culm, a few inches tall will still be growing at the base so any internodes left behind could continue to expand, so they need t
o be broken off very low down to avoid further growth. I always just snap the off at ground level which seems to do the job.

Excellent info. I always found it odd that bamboo was said grow from the top but grass from the bottom. The main growing area on a culm is concentrated near the top whereas in grasses its near the bottom (hence the need to mow it all the time!)

[Nathan]

Yep I always snap any unwanted culms off at ground level & it kills them

[cordyman]

They grow from the top of the culm so cutting the tops off should stop them.

I don't think that is quite true or at least not the full story. I have taken a broken-off juvenile culm and gradually peeled away the sheaths. Once removed, you can see all the nodes are closely packed together towards the top and are gradually further apart heading toward the bottom. This suggests that many of the internodes grow together but from the lower portion quickest and the culm expands like a concertina but biased towards the bottom first.

When a culm is a couple of feet tall it will consist of several fully grown internodes at the bottom and the top portion still having tightly packed nodes and the most growth activity will be about 2/3 up the culm. This gives the impression it is growing from the top. A very short culm, a few inches tall will still be growing at the base so any internodes left behind could continue to expand, so they need to be broken off very low down to avoid further growth. I always just snap the off at ground level which seems to do the job.

Great info


Totally ties up with what i've found as the ones i've pruned further down havn't budged much. I'll try the snapping method next time.

I've read the new culms are toxic when eaten etc, is there any need to wear gloves etc when snapping them? Usually make tea after my potter in the garden

[simon]

I don't know about toxicity, but those hairs on the sheaths of Fargesia robusta can be quite an irritant when they stick in your skin. I remember last year when I was removing old spindley culms from the centre of the clump, I got them all stuck in my forearms.

[cordyman]

Thanks Simon!

Also on the subject of thinning culms

in this pic for example





If I were to remove some of the original/older thinner culms, does that make way for new culms next season in that spot, or as the canes are so tightly packed at the base will new culms only ever grace the edges?

[Javeo]

I don't think they are toxic as bamboo shoots are eaten, and are quite nice, in Asia. Let them grow to 20cm and then you can harvest them for use in stir frys

[simon]

Some new culms do emerge inside the clump but I can't say whether they would necessarily come up where you have thinned out, or if they will necessarily be larger than the ones you removed, but I would give it a go and see what happens next spring.