Teasel is an invasive plant where I live, and the orchard mason bee is a native, so I don't feel guilty about uprooting teasel to make homes for mason bees. If you gather them during the growing season, gather the biggest teasel plants you can find. It will be easier to drill out because the skinnier ones aren't wide enough. Search for teasel on google images and you will probably recognize it, that's how I did. With the fresh growing teasels, cut them into sizes about 6". THe teasel tubes are internally blocked off on one side, which is perfect. You can literally jam a long pencil down it for 6" long because like he said on the video the pencil is 5/16" wide and make them quickly on a freshly growing one. If you use dormant season teasels, you'll have to use a drill. The drill bit will probably have to be a special one, because most drill bits are about 4". You won't get the right ratio of male to female with like 2-3" of tube. A 12" drill bit is what I got, about $10, well worth it. A PVC pipe with an angled cut to make a roof on the top on each side works great to house the reeds. Put a dab of whiteout on the drill bit to know when you get near 6". You can switch the sides of the tube you use to keep the roof on top when you're cutting, say a 10' PVC tube into individual sections for houses. Each house for bees could be about 13-14" long on the long sides if you want it pointing both ways, so you have a few inches for a roof on each side. Even number of tubes. Hanging them toward the east for morning sun works well if you're only going one direction. You can put them in a tree so during the summer the leaves will stop them from getting too hot. Metal gets too hot if in the open. Cardboard disintegrates in the rain. PVC/plastic seems best. I recycled mine. SOmetimes the bees will wait a year to use it, so I prefer to gradually increase my mason bee population. The winter is a good time to prepare the reeds because there's less to do in the garden and you need to be ready when February/March comes with the blooms and the bees waking up. I also did notice the sunchoke/Jerusalem artichoke and I'm going to try that this winter too. Ask away if you have questions or share your ideas so we can learn more.
Yes. It's on the top of this page now as I'm writing to you, but it's also in this topic, mason bees, on the thread "orchard mason bees", way down past the playing card. It' s a great video about them. In it, Jen Davis talks about how the wooden houses aren't as good if you want to clean them. I've made several out of wooden blocks but I'm making them out of teasel now.
Teasel is great (more later) because you can use it one year and then toss it to reduce parasite infestations. This is why most serious mason bee raisers do not use SOLID wooden blocks. Each year the pests get more and more populated. Think crop rotation and how the pests build up if you keep the same thing growing in the same place year in and year out.
One issue with teasel, and other reed, nesting material is parasitism. Wasps find them quite easy to penetrate and lay their eggs in the bee chambers.
I purchased a starter group of cocoons and a tray system from Crown Bees. The wood is more secure from pests and the tray system allows yearly cleaning without too much trouble.
Teasel is not invasive. It is trying to tell you that there is some medical condition in your area that needs to be addressed!!! Teasel is GREAT for deep seated pain as in Lyme's disease or fibromyalgia. It actually expels the little beasties out of muscle tissue so that your body can deal with them. So, harvest all the teasel reeds you need, but say NICE things about it!!!