ON THE GARDEN PATH by Carolyn Herriot

The pollination of flowers enables plants to bear fruit and set seed for future generations. Seventy-five percent of our food plants depend on being fertilized through pollination. Bees are Earth’s number one pollinators, responsible for pollinating one third of the crops that feed us, so we should be concerned about protecting their well-being.
There are thousands of different bee species worldwide that fall into either the category of social bees, such as honey bees and bumble bees that live in hives, or solitary bees that live and nest alone. Solitary bees lay eggs in their own nests, from which young bees emerge in spring to feed on nectar and pollinate flowers in the process.
The blue orchard mason bee, Osmia lignaria, is solitary and indigenous and nests in forested areas on both the Atlantic and Pacific coasts of North America. This wood-dwelling bee emerges when the temperature reaches 14°C (57°F). It’s no coincidence that this is also the temperature when fruit trees blossom. Blue orchard mason bees are very effective pollinators, visiting up to 2,000 blossoms a day. These non-aggressive bees are easily mistaken for blue bottle flies, as they are a shiny, blue-black colour and slightly smaller than a honey bee.
Bees are the principle source of pollination for flowers, fruits and vegetables and it’s in the gardener’s best interest to provide them a healthy, pesticide-free habitat. Here are some suggestions for encouraging the presence of pollinating bees in your garden:
• With a limited foraging range of 91 metres (100 yards), blue orchard mason bees pollinate plants close to their nests. Provide them with nesting boxes that are simple to make or you may also purchase them. Make sure the nesting cavities are in stackable layers so they can be removed and cleaned to prevent the spread of deadly bee mites.
• Leave dead wood, branches and tree trunks in the garden where wood-dwelling bees can nest.
• Leave areas of non-cultivated, undisturbed soil for bumble bees, which live in the ground.
• Grow single flowers in blue, yellow and purple that bloom in April to early June to attract native bees that collect nectar and build their nests during that period.
• Provide a constant source of flowers for bumble and honey bees, which feed for the entire growing season. Short-tongued bees like the shallow flowers of the Umbelliferae, Brassica and Compositae families. Long-tongued bees are attracted to flowers with deep corollas, such as larkspur, columbine, snapdragon, mint and members of the Solanaceae family.
• Double flowers do not attract bees. They are showy, but produce less pollen.
• Native plants supply bees with a good source of food.
• Provide a shallow water source in which bees may dip and sip and make mud for nesting.
• Avoid pesticide use. Residues on flowers can be fatal to bees. If control is necessary, use the least toxic product and spray late in the evening when bees are not flying.

From A Year on the Garden Path: A 52-Week Organic Gardening Guide by Carolyn Herriot. Second edition $24.95. Available from your favourite bookstore or order online at www.earthfuture.com/gardenpath.