January may not be the first choice when backyard gardeners are asked their favorite month, but for me it ranks a close second to the one that lets me bury my first seed. January is the time to review the past and plan for the future. It is the time for cleaning, repairing and building homes for my garden helpers, birds, bats and bees. This week I am making several bumblebee nesting boxes, hoping to draw some of the fuzzy pollinators to the cucumber patch which, according to my journal didn’t live up to my expectations.
Journal note, Sept. 8, 2004:
Picked 4 cucumbers -- small, misshapen, few seeds! Poor pollination?
On an open-pollinated or heirloom cucumber plant, the first 10 to 20 flowers are male, and for every female flower 10 to 20 male flowers are produced. In order for the flower to develop into a fruit, pollen must be carried from the male to the female flower, the one with the tiny ‘pickle’ beneath the yellow petals. Poor cucumber set is common during cool or damp weather when most bees are inactive.
Some hybrid cucumber varieties are what are known as gynoecious, they only produce female flowers. They tend to bear fruit earlier, with a more concentrated set and better yields overall but require a pollen source, so seeds from a different variety are usually included in the seed packet. It’s logical that more bees are needed for these hybrids.
The environmental news outlets have been talking about the worldwide decline of pollinators for years. If our small homestead was larger and more rural would invest in a honeybee hive.
Which type of cucumber did I plant? Straight eight, an open-pollinated variety. Could there have been another cause for the ugly fruits? Of course, but it was a wet, dreary summer and aside from smooth-tailed hornets and yellow jackets I didn’t see many bees in the garden. I need some cute fuzzy bumblebees or honeybees that pollen really sticks too.
Bumblebees are similar to honeybees in that they live in colonies and even produce honey, though in small amounts. Whereas honeybee colonies number from 20,000 up to 80,000, bumblebee colonies are 50 to 300 individuals. Unlike honeybees, bumblebees will forage in cool, cloudy weather. The larger size of bumblebees allows them to transport more pollen. They are also impervious to the varroa mite, a leading cause of honeybee decline.
Bumblebee nest boxes are available at some garden supply centers for about thirty dollars apiece; one example is the Humble Bumble Home, offered by a Washington-based, family-owned business called Knox Cellars (www.knoxcellars.com). But they are relatively quick and easy to build for anyone with basic woodworking skills.
Material list:
5 feet of 1x6 untreated pine or hardwood
Quarter sheet (2x4) of 3/4 inch plywood
5 feet of 1x1 or similar sized molding
7 inch section of 3/4 inch PVC pipe
Screws or nails
Tools:
Drill with 7/8 inch and 1/4 inch bits
Saw
Screwdriver or hammer
Assembly:
Cut 1x6 board into lengths; front and back -- 15 inches, sides and divider -- 8 1/2 inches
Rip divider panel to 4 1/2 inches x 8 1/2 inches
Cut plywood; bottom – 12x15 inches, top – 14x17 inches
Fasten front and back panels to side panels, making a box 10x15 inches
Fasten bottom plywood to box, leaving extra 2 inches extending past front panel for porch (landing pad).
Drill 7/8 inch hole in divider panel, 1 inch from one end and 1 inch from bottom.
Insert divider panel 5 inches from one end and fasten to floor (gap above is for air flow).
Drill 7/8 inch hole in front panel into smaller “vestibule.”
Insert PVC pipe in exterior hole, flush with front panel, add a drop of hot glue or caulk if needed.
Drill several 1/4 inch holes in the floor for drainage and through the side panels (near the top) for ventilation. Fine screening can be stapled over the inside of the holes to help prevent access by uninvited guests like ants.
Flip box over onto top panel with three sides 1 inch from edges, (more overhang on the front will provide a “porch roof”) and mark the outline of the box onto the top panel.
Cut 1x1 into lengths; 2 pieces 15 1/4 inches, 2 pieces 11 3/4 inches
Fasten 1x1s to top on marks so that the roof will slip over box easily
Add a Plexiglas panel to your box before installing the roof for safer inspections. Waterproof the roof with paint or roofing material. Paint a flower at the entrance. Add legs to keep box off the ground.
Furnishings:
Fit corrugated cardboard on the floors of both rooms to soak up waste.
In the larger room (the brooding chamber) place a handful of cotton batting or similar material for nest building. Some commercial bumblebee houses provide a small container of sweet syrup in the vestibule for the queen.
Placement of bumblebee house:
Your bumblebees won’t want to be flooded; choose a piece of higher ground. Place it on bricks or blocks to prevent water from rotting the bottom. They will enjoy the morning sun; face the entrance east or southeast. Don’t put it too close to a child’s play area or where you will be mowing the grass; bumblebees are not aggressive but will sting if provoked.
My wife thinks I’m crazy, encouraging bees to take up residence here when I am allergic to their venom. I tell her they won’t bite the hand that feeds them; it wouldn’t be logical.