Ann Wright: Marvelous mason bees |

Ann Wright: Marvelous mason bees

Ann Wright

Oh, the magic of spring — soon to be. Didn't we have that in February? Unless the recent frosty, snowy, hail-ridden weather has wiped out blooming fruit tree buds, orchards and gardens will soon be buzzing with honey and native bees. Gardens will be awakening, soil warming — there is so much activity in a March garden.

Gardens are wonderful, changeable spaces where many creatures interact with plants. Mason bees are among them.

Mason bees (Osmia lignaria), also known as orchard mason or blue orchard bees, are one of over 1600 species of bees in California. Sometimes mistaken for common house flies, orchard mason bees are about a half inch long and sort of metallic blue-black in color. These gentle little bees are not aggressive but are power-house pollinators.

Unlike the social honey bees living in colonies, mason bees are solitary. A single female lays eggs in nests close together, typically in existing wood holes in trees, among shingles on houses, nail holes or nesting houses created specifically for them.

The female gathers several loads of pollen and nectar from spring blossoms and stashes it in the back of a nesting hole. Eggs are deposited in the hole and sealed with a mud plug (hence the bees live up to the name, "mason"). The process is repeated until the entire hole is filled with the little egg chambers. A final thick mud plug is then added to seal the nest.

The gathering of food, laying of eggs and sealing the nests continues until around early June when the females die. In the nesting chambers, the bees mature through the summer and hibernate through the winter as adult bees. The following spring, the bees chew through the mud plugs to emerge and start the process over again.

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There is only one generation of orchard mason bees per year.

Mason bees are just some of the fascinating creatures to be found among the plants. To learn more about them, Nevada County Master Gardeners are having a free class today, "The Amazing Mason Bees" from 10 a.m. to noon at the Elk's Lodge in Grass Valley, 109 S. School Street.

Prepping your garden for spring

Hopeful that the wet weather will continue for a while, there are many things to do in the garden between storms.

The Western Nevada County Garden Guide suggests, if summer and fall-blooming perennials are crowded or the bloom was sparse, divide them when starting to sprout. Lift clumps with a spading fork and make clean cuts with a spade. Use the outer portions of the clump and discard the center growth.

Start weeding now — consider what plants are weeds and not to be tolerated. Pull and discard or place in a pile separate from the main compost pile. The weedy organic material will break down, but the unwanted seeds may still be viable and you don't want them mixed in with the vegetable garden compost.

For more information on suggested control for weeds, consult the UC Davis Integrated Pest Management website at and click on the "Home, Garden, Landscape, and Turf Pests" box. Look for the link to weeds.

Set out potato tubers, lettuce, rhubarb, parsley and cole crop starts (plants belonging to the Cruciferae or mustard family of plants). Some examples of cole crops include brussels sprouts, cabbage, cauliflower, kale, broccoli and turnips. Radishes, carrots and beets can be direct seeded now.

Warm-season seeds can be started indoors and transplanted two to three weeks after the last frost and as soon as the soil has warmed. If starting seed indoors is not on your agenda, you may want to purchase some.

There will be many varieties of vegetables, herbs, annuals and other surprises at the popular Master Gardener Spring Plant Sale from 9 a.m. to noon May 12th at the Demonstration garden.

Thinking about growing tomatoes? Tomatoes can be started indoors six to 10 weeks before the last frost date, and transplanted two to three weeks after the average last frost. To learn more about starting tomatoes, the Master Gardener's workshop, "Totally Tomatoes" is scheduled from 10 a.m. to noon Saturday, March 17, also at the Elk's Lodge in Grass Valley.

Discussion will include how to start tomato plants from seed, the best conditions and strategies for growing tomatoes in our area, and learn about pests and diseases that plague tomato plants.

For more information about Master Gardener workshops and events, go to the website at or call 530-273-0919.

Ann Wright is a Nevada County Master Gardener.

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