Solving the Pollinator Problem
You’ve probably heard that honeybees are facing a mysterious crisis right now in North America, and to some extent Europe as well - something called Colony Colapse Disorder (CCD). And this is a problem because many of our food crops are pollinated by bees. Without good pollination, you don’t get good production.
Many want to blame modern agriculture (pesticides, genetically modified crops, monoculture, etc.), and while those seem like great places to look, the truth is we just don’t know. One researcher compared it to trying to solve a murder without the victim’s body.
Without knowing the why, it’s hard to know what to do. Planting a pollinator garden is a great idea. Here’s another one: Attract other pollinators.
Mason bees are a North American native, and don’t seem affected by CCD. Attracting them is not hard. If you have a drill, a 5/16-inch (7mm) drill bit, and some scrap lumber, you have everything you need to create a mason bee habitat.
If you want the long version, get a copy of The Orchard Mason Bee by Brian Griffin and Sharon Smith. The book has a lot of details for building optimal mason bee habitat, protecting from woodpeckers, wasps, weather, etc. It’s a pretty good book - interesting and easy to understand. I’ve followed their instructions to make some mason bee nesting sites out of scrap lumber. (As you can see from the photo below, aesthetics weren’t a big concern for me…)
Here’s the short version: Drill 5/16″ (7mm) holes, as deep as your drill bit will allow, into blocks of untreated wood. The holes can be as close as 3/4″ apart in a grid pattern. Six-inch depth is supposed to be ideal, but 3 1/2″ depth will work pretty well. The more holes you can drill, the more bees you can attract - hundreds or even thousands of holes are not too many. Set or hang the wood in a place that gets some sun early in the day but has some protection from rain (like under east or south facing eaves).
You might also want to plant some early-flowering shrubs near your nesting sites, so that when the bees emerge in spring, they have an easy nearby food source. The authors recommend Pieris japonica, but I’m going to try forsythia myself.
There’s more to it if you want to keep them around for the long haul and minimize their parasites and such - but not a lot. You can sanitize the nest blocks with 10% bleach each year, rotate through a couple sets of blocks from one year to the next, or just burn the scraps as firewood, and drill out new ones the next year.
You won’t get honey, but you will get your garden and/or fruit trees pollinated. And the odds are pretty close to zero of ever getting stung by a mason bee.
So get drilling!