When Do I Take Them Out?

[Michael Palmer]

My daughter gave me a 2x4 with mason bee holes. I talked to a grower in Oregon, and was told that my -20F weather was too cold to winter Mason bees. So, I've kept them in the frig, in an open plastic sandwich bag. When should I put them out?

We still have a foot of snow, and it's +5F this morning. First pollen is still a few weeks away.

[BjornBee]

My daughter gave me a 2x4 with mason bee holes. I talked to a grower in Oregon, and was told that my -20F weather was too cold to winter Mason bees. So, I've kept them in the frig, in an open plastic sandwich bag. When should I put them out?

We still have a foot of snow, and it's +5F this morning. First pollen is still a few weeks away.

MP, once you take them out of the fridge, they will pop out in a relatively short period of time. 3 to 5 days comes to mind. That's the danger with an early warm spell, where they start hatching out, and then they die as it gets cold again, or they have nothing to forage on.

Most people I know, keep them in cold storage until the first fruit trees bloom. Masons are specialists on fruit blossoms and that is thier preferred pollen source, although they will work other flowers. So I would be looking at a week prior to the apple blossom opening in your area.

Masons are finicky bunch. Starting with a small number sometimes spells disaster. They either just dwindle or will move off to another place. So don't be surprised if they hatch out and don't do a lot. They must also have adequate pollen they prefer (Fruit trees) and a source for water and mud close by. Their whole existence is within about 100 to 200 yards from where they hatch. They don't travel far as seen with honeybees. So it's location, location, location. Even with a perfect spot, starting a colony with a low number of tubes sometimes just does not work out.