I once paid a visit to a new beekeeper's hives and noticed that every weed under and around them was "graveyard dead" (as Jerry Clower used to say). I was in awe and wanted to know the secret. When I asked him how he was killing them, he didn't hesitate to say Round Up. While I praised his efforts to keep his yard free of weeds, I gave him some friendly advice and told him to stop using chemicals like that around his bee hives. While Round Up is an herbicide and not a pesticide, it has been shown to be toxic for animals, fish and humans. And it is more than likely toxic to honey bees too. I told him one natural weed killer is to mix one gallon of white vinegar and one large container of salt, then spray it like Round Up. You can also add some dish detergent to the vinegar and salt mix. The good thing, it really works. The bad thing, you have to reapply it frequently.
Before I got my first colony of bees, I tried everything you could think of to kill a big bed of bamboo behind my house. The previous owners apparently planted it, and what they were thinking, I don't know. The stuff is relentless and you can't kill it. No matter what I've used, nothing has worked. I even read where people have poured concrete over it and the stuff will continue to grow and sprout at the end of the concrete pad. My best bet would be to get a panda but I don't think that is very practical.
Year ago while doing some research on how to eliminate this evil weed, I ran across an article that said of you will apply Morton's water conditioning salt, it will kill tough weeds but not impact the environment like toxic chemicals. So I tried it and sure enough it worked. Let me clarify, it killed the grass and other weeds where it made direct contact, but did little to the bamboo. While that part was a failure, I did learn that the water conditioner salt is a cheap and non toxic method to deal with grass. And it is perfect to put under bee hives since it has no smell and nothing that will hurt the bees if they come in contact with it.
The pellets are about the size of medium gravel. And they are big enough that they won't disappear in one rain event. So as they melt, they leave enough residue kill the grass and will continue to work until they disappear. Once they're gone, simply apply more pellets. I paid a little over $8 for a 40 pound bag, and you can probably get it cheaper if you shop around. But a word of warning - don't put them near flowers or other greenery you want to live. While it doesn't work with bamboo, it does work on other living plants, so be careful where you put it. And if you accidentally get some on plants you do want to live, get it up before it rains or you use a water hose.
Good luck if you try it and let me know how it works for you. Oh by the way, the bamboo is still out of control although I keep it at bay with clippers and the lawnmower. And who knows..one of these days, I may have to get that panda after all!