The most common pollination problem I have in my garden is early squash. For years I’ve expected that the first female blossoms will fail, and although I’ve tried hand-pollination with a q-tip or artist’s paint brush I’ve not had much luck with that. Honeybees and orchard bees are busy with other things in this early season and the squash blossoms often went untended for a couple of weeks. The past two years, things have been different. Suddenly I have lots of bumblebees.
I’ve always seen at least a few in the garden, but the past couple of summers the garden has been busier with bumblebees than with honeybees. Honeybees enjoy the big nectar flows, the blossoming trees and the field crops, the blooming thickets. Honeybees often skip the garden plants. In my garden the favorite crop for the honeybees is field mustard, which I grow to eat and as a cover crop and of course as forage for the honeybees. But, if they are working the field mustard, there’s no reason to think they are working the zucchini or the summer squash, and in fact I seldom see them doing so.
Never mind. The bumblebees now have that under control : ). They have arrived early these past two years and stayed the entire summer, working the garden in large numbers, at least for bumblebees. I can easily count 50 out there on a sunny day in midsummer and possibly there are more. They love the squash blossoms and prowl happily among the beans as well. That shouldn’t be a surprise, because both the beans and the squash are Native American crops and the bumblebee evolved to fit them. The size and hairiness and the special vibration of the bumblebee is specifically designed for pollination of squash and other large-blossomed plants. Squash and bumblebees evolved to fit one another. For two years my early squash blooms have been mostly setting fruit instead of mostly fizzling and rotting. Success is better later in the season when the bumblebee numbers increase, but it’s a genuine difference even in the early season.
I’ve only been helping the bumblebees by accident, but I’ve been helping. I have an active hive or possibly two here on the property because I give them habitat. I had actually thought that bumblebees live in underground nests like yellow jackets, but I’ve never actually found a bumblebee nest. It turns out that they are ground-dwelling social bees who live in colonies of 20 to 50 workers and a queen. They make honey as needed, and are not a commercial source of sweets for humans, but they are best pollinators ever. They can nest in a variety of situations including abandoned animal burrows, so my yard has an abundance of tunnel opportunities, thanks to Moleman’s endless hunting. Bumblebees also nest under piles of debris like fallen leaves, and I have permanent deep mulch of hay and leaves around some of my vines and fruit trees. Bumblebees also nest under piles of brush, and I am constantly acquiring brush to use when building new garden mounds. Some piles might stay in place for two years, and now I’ll worry about using them in the wrong season. I wouldn’t want to disturb a nest of good bumblebees.
Bumblebees die off completely in early winter except for the queen, who burrows underground and winters over in her own tiny tunnel. The first bumblebee of the spring is the queen, out on her own to find the squash blossoms.
I found lots of interesting info about bumblebees at LiveScience: Facts about Bumblebees