To improve bee pollination during bloom, tree fruit growers should focus on colony strength, number of colonies per acre, colony placement, and timing of colony introduction and removal, says a Washington beekeeper.

Jeff Lunden, owner of Corral Creek Pollinators and a small pluot orchard in Benton City, Washington, offers the following pollination tips:

• Colony strength

Strong, healthy frame of bees should be about two-thirds covered, holding approximately 2,400 bees. A hive with 8 to 10 frames that are two-thirds covered, results in 19,200 to 24,000 bees. Two-thirds of colony bee populations are house bees, with the remaining third serving as foragers. Frames with extra numbers of bees provide more foraging bees.

Frames should be disease free.

Request "queen-right" colonies because those require pollen to produce food for the developing brood, driving the demand for pollen collectors.

• Colony number

Recommended number of colonies per acre:

Cherries—2 to 3 hives per acre

Apples—1 to 2 hives per acre

Evaluate bee field force by counting bees for one minute as you walk around a fruit tree. Good field force numbers are:

Apples—20 to 25 bees per minute

Cherries—30 to 35 bees per minute

Pears—10 to 15 bees per minute

Semidwarfing trees require fewer bees, around 10 to 15 bees per minute.

• Colony placement

Place hives on top of fruit bins to:

—warm hives faster

—make them easily seen by tractor drivers

—help protect from predators, like skunks.

Group six to eight hives together for better cross pollination and to encourage better foraging deeper into orchard.

Place hives on orchard perimeter.

• Timing

Wait for signs of bloom (10% bloom) if competing bloom is in area (for example, plums next door, dandelions). Bees habituate on competing bloom and will stay awhile before moving to later blooming trees.

For overset or late bloom concerns, remove hives promptly.

Give 1 to 2 days notice for hive removal; removal is part of bee service.

• Enhancing pollen supply

Pollen inserts/bouquets are effective when put in front of hive.

Pollen delivered by helicopter or puffers is not as effective, but bees can move some pollen from leaves to the stigma.

Bees need water, but not in buckets where they can drown or from overhead sprinklers. Water sources (such as puddles) should be located away from roads and traffic areas. —M. Hansen