I just got off the phone with Dave Hunter, probably the number one native bee guy in the world. He runs
https://crownbees.com/ -- Here's a video I made with him, and the video seems to be super popular (more than a quarter million views)
So there's a bunch of important stuff and I wanna write it down before I forget.
NB007: reeds are better than trays which are better than blocks.
NB008: 75% of all pollinators are ground nesting. The best thing is TRUE no-till systems - like
hugelkultur
NB009: If you get an insect hotel, or solitary bee house ... if you care for it properly every year (take out the cocoons, put in fresh reeds, etc.) it will house pollinators for 20 to 30 years. If you forget to take care of it, or move, or whatever - it will be fine for five years.
NB010: brush piles house a lot of pollinators. Try to work a couple of beefy logs into the middle of your brush piles. And try to add teasel, japanese knotweed and bamboo to your brush piles.
NB011: When you make your bee watering station - complete with a place for all sorts of insects to get water - maybe add a pound of clay to one side. That makes for squishy clay that mason bees can use.
NB012: three season nector/pollen source.
NB013: grow more food. You food will have a bloom at a particular time of year, and the pollinators that groove on that time of year will set up camp in your area. More and more food, more and more pollinators. Keep expanding. If you grow it, they will come (probably). Of course, if you put in 40 acres of all the same thing, they aren't ready for that, so you might be disappointed. But if you start with a rich
polyculture on a quarter of an acre, they will be ready for the next year when you do a full acre (probably).