Alternative Mason Bee Tubes

What are my fellow Permies using instead of, bamboo, paper, or wood tubes? I ask because here in the Similkameen(southern British Columbia) bamboo grows slow and small, driving rain and variable winds cause paper to disintegrate, so far drilling holes into fir lumber has sufficed, but fir is not sourced locally. I had an idea about using dried, hollowed out sunflower stocks, chopped into the appropriate length, but yet to act, and was curious if anyone had alternative ideas.

At The Color Green, they have noticed a similar thing in the simplicity of building mason bee nests. As long as the holes in the tubes are big enough for the bees to fit in, they can use it. For the tubes they made, they used stems from the cup plant.

Rose, raspberry, and elderberry have hollow stems. Lots of annual weeds have hollow stems. I also drill holes in any available logs or wood. Branches cut off the apple tree. Snags. Etc.

Here's rose stems being used for native bee/wasp nesting sites.

Here's my sunflower, and mullen stem, beta bee house, minus 1/2 inch chicken wire to keep out birds.

I'm going to experiment with cow parsnip stems this season.

sunchoke stems and japanese knotweed also work well once they're dried. I just crop them into random lengths and pile them in sheltered places around the property. Chop and drop habitat.

We just drill holes in some chunks of oak and mounted the blocks under the southern eaves of our toolshed. After one season, mason bees began to move in. We get the chunks from a local pallet mill for free.

Some cool things happen by accident. I use a self propelled mower with a bagger to save most of my lawn clippings and last fall I covered a small pile of grass clippings with a tarp, then forgot and left them all winter. I uncovered them this spring and when I (later) started to pick them up with my hay fork at least a hundred mason bees came boiling out. They weren't aggressive, just startled. I'm planning on experimenting with turning my accidental bee habitat into something intentional...maybe add some protection with a couple of concrete blocks holding a fiberglass roof over a pile of grass clippings.

Teasel stems are hollow and work great! Wear gloves to rub off the little thorns, they break off easily but they can poke you. Cut on a bandsaw or use a dremel to prevent crushing them.

i second japanese knotweed. the stuff grows everywhere nowadays and is easy to cut and also split to harvest the cocoons in the fall. the woodpeckers are fond of the cocoons so its important to harvest them and store in the fridge till spring.

Doing the same this year for Mason Bees. I use 1/4 parchment paper tubes inside so I can reuse tubes and easily harvest cocoons