I have decided to kill off my Robt Young bamboo. After 5 years it has been defoliated almost every year and suffered culm damage two years. I have planted Decora next to it and want to give this one more room. Last fall I cut down all the culms and sprayed the remaining leaves with roundup. It has put up about 20 shoots this week.
My question is should I just cut off the shoots or wait till they leaf out and then cut them off? Fortunately the decora and robt young have very different shoots.
Thanks

You can wait until shoots start growing branches and then cut them at ground level. That way photosynthesis won't start and they will use as much energy as possible.

I've always had success with putting the roundup directly into the fresh cut culm. It goes back quite a ways and takes out culms down the line.

I've never been much for pouring chemicals on the ground or my plants. A pickaxe and shovel are my preferred herbicide.

I still believe in the mow, prune, kick, chop, lop, grass seed method. I haven't done it with bamboo yet, but did do it to 6000sqf. of Japanese Knotweed and it worked. That root (Rhizome) system is is crazy. Bamboo rhizomes are a lot easier to eradicate.

I really doubt that roundup will have much of an affect on the rhizomes because it might take out the shoots that are firing, but there are likely other dormant buds that will take their place so it is easier to lop them, whack them down with a machete, or when they come up small enough, mow them over. After about 2 months, there will only be tiny survival growth with canes under 1/8 inch in diameter, even with the most persistent species, and I don't think Robert Young can downsize that far without rotting or aborting their shoots. There's no need to dig anything up because those rhizomes are biodegradable.

I've helped a neighbor take out a grove of yellow groove and bissetii that they wanted to get rid, which was right after new shoots branched out with a little bit of new leaf growth. All the starch has moved out of the rhizomes, and into the new culms by this point so lopping all the culms to soil level was enough to almost kill the groves. After that, there was barely any survival growth because the groves were completely drained of energy, and regular mowing after that got the job done.

Just try taking rhizome divisions after shooting season. I know that eBayers will sell rhizomes after shooting season thinking it doesn't make a difference, but I've tried rhizome divisions several times right after shooting season, and even though some buds manage to elongate, I have never gotten a viable rhizome division when their starch levels were depleted. I think killing off a grove works the same way.

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