The secret to splinter-free cut bamboo tubes? Harvest the bamboo while it’s still green and soft, and chop it into appropriate lengths with a utility knife blade.
The problem
Looking toward next spring, I’m going to need bee nest tubes to replace the ones in my current bee hotel. Best practice is to use new, clean nest tubes each year. The current, successful hotel from Home Depot has bamboo tubes glued into place. I’ll need a replacement for that for next spring, and then, next summer, once the bees have emerged, I’ll have to break those out of there and replace them.
I have plenty of bamboo growing around the edges of my yard. So it seemed as if I had an infinite supply of raw material.
But the cut ends of the bamboo have to be smooth, or you risk injuring the delicate wings of bees. And, try as I might, I could not manage to make a clean, splinter-free cut in cured bamboo. Nothing I had — no clippers, saws, cutting disks, or blades — yielded a smooth edge.
That meant that I’d have to hand-sand every bamboo tube, both the inner and outer edges. And that was a total non-starter for me.
The solution
But this spring, as bamboo shoots have started pushing up through the soil, I decided to try something different. It takes a number of days for bamboo to harden, once it emerges from the ground. What if I tried cutting bamboo when it was still green and soft?
The setup above worked almost flawlessly, as long as I used the “right” bamboo, which in this case was a species that didn’t get more than about 8′ tall. Hold a utility knife blade in a set of vice grips, and strike the blade with a hammer to drive it cleanly through the soft, green bamboo.
Almost flawlessly. If you are dumb enough to strike a razor blade with a hammer, you need to be smart enough to wear eye protection. Because, if you hit it hard enough, it will shatter. Like so.
I shattered that blade trying to drive it through a piece of green bamboo from a different species, a type that grows to about 25′ in this area. Those bamboo stalks were much too tough to be cut easily with this method.
The end product was just about right. Bamboo tubes, closed on one end, roughly 6″ in length.
Of the diameters that solitary bees might use, these all came in around the low end. I think the largest usable one was barely 3/8″, and the smallest came in around 3/16″, which is at or around the 5 mm lower bound typically mentioned for bee nest tubes.
Not to worry, though. Out of the incredible variety of noxious weeds that come up in my yard every year, we always manage to get a few pokeweed (or pokeberry) plants. Even though mature pokeweed is poisonous (to humans), pokeweed stems are frequently listed as a natural material suitable for use in bee nests (e.g., this reference). Given that our pokeberry plants will grow to the size of small trees if left undisturbed, all I need to do is leave one or two alone, and I should have all the large-diameter nesting tubes that I need.
Edit 4/7/2024: As I found out the next spring, if you want to harvest native plants such as pokeweed for use as bee nest tubes, you need to do that while the plants are still green, or, at least, before they’ve been out in the weather all winter. When gathered up some of last year’s poke and sunflower stems, this spring, no tool that I owned would make a clean cut in those dry, brittle, fragile stems. They would rip and shatter, but not cut. Maybe there’s some technique that will work, but I never found it. The moral of the story is, harvest next year’s bee tubes this year.
