Bees to pollinate your Vegetables and Fruits

Digger bee coated with pollen - Whitney Cranshaw

Devoting valuable growing space to flowers to nurture bee pollinators may seem like a waste of time to vegetable and fruit growers. Perhaps it's time to rethink and plant some low-care perennial flowers for bees.

Pollinators have been in decline with increasing urbanization and the mysterious honey bee colony collapse disorder. We need bees to pollinate our food. Vegetable growers need to be concerned about pollinators for their vine crops: cucumbers, melons, squash and pumpkins. Fruit growers are even more dependent on pollinators for brambles, strawberries and tree fruits.

Sweat bee and honey bee - Whitney Cranshaw

Although you may automatically think of honey bees, don't sell bumble bees and solitary bees short when it comes to pollination. There are a whole variety of native solitary bees to consider.

Some of the better low water and low care perennials to consider growing for bees are:

• Sunflower (Helianthus sp. but not pollen-free florist types or fancy doubles)
• Catmint (Nepeta - extend flowering by cutting back after first flowering for a second flush of bloom)
• Beardtongue (Penstemon sp. including Rocky Mountain penstemon, P. strictus)
• Russian sage (Perovskia atriplicifolia)
• Mint (Mentha sp.)
• Purple coneflower (Echinacea purpurea)
• Blue mist spirea (Caryopteris x clandonensis)
• Lavender (Lavandula angustifolia)
• Silverheels horehound (Marrubium rotundifolium)

Also consider succession of bloom over the growing season. Don't know when perennials bloom? Click to find a helpful publication from Utah State University Extension complete with flower bloom time chart that is highly applicable to us in Colorado:  Gardening for Native Bees in Utah and Beyond.

Bees do more than pollinate

The buzz of bees in flight causes some caterpillars to slow or cease feeding on plants.

German researchers Tautz and Rostas report in December’s Current Biology a 60 to 70 percent reduction in pepper leaves consumed by beet armyworm caterpillars in tented enclosures with honeybees than in tented enclosures without bees after two weeks.

Several caterpillars have evolved freeze-motion or drop-off-plant avoidance behaviors in response to predatory wasps. Sensory hairs on the caterpillars pick up vibrations from flying wasps and trigger the response. These behaviors are often combined with defensive coloration that blends caterpillars into the background color of the plant.

So bees can be beneficial to plants by slowing feeding even though honeybees are not predators of caterpillars. Note that pepper flowers (like those of tomatoes and eggplant) self-pollinate with wind movement, not from visits by bees or other insects.

This may be another reason to plant bee-attracting flowers in your Colorado edible garden in addition to wanting bees for pollinating squash, cucumbers, melons and pumpkins.

[Honeybee photo credit: David Cappaert, Michigan State University, Bugwood.org]

[Beet armyworm photo credit: Frank Peairs, Colorado State University, Bugwood.org]