Adams County Master Gardener
It has been calculated that one of every three or four mouthfuls of food that we eat and beverages we drink is dependent on pollination by animals.
That includes crops such as most legumes, vegetables, fruits, nuts, berries, herbs & spices, oils, seeds and grains.
That's why we all need to be alarmed by the decrease in native pollinators. Human activities are the biggest reason for this decline, especially
habitat loss and pesticides.
Pollination is a part of life that has evolved over eons to benefit both flowering plants and pollinators. When pollinators visit flowers, pollen rubs
or drops onto their bodies. The pollen then is transferred to another flower or a different part of the same flower. This process is a vital stage in the life cycle of all
flowering plants and is necessary to start seed and fruit production in flowers.
Some plants rely on wind to transfer pollen, but 90% of all plant species need the help of animals. There are more than 200,000 species of animals
around the world that act as pollinators. A small number of these are vertebrates, such as birds, bats and small mammals. The vast majority of them are invertebrates,
including bees, beetles, butterflies, moths and flies.
Native pollinators have not gotten much attention recently, but we need to become more aware of their value, and create habits to attract them to our
yards. Native pollinators are adapted to local climate conditions and soils and thus require less maintenance.
In the United States, honeybees and thousands of species of native bees are responsible for pollinating crops. The great majority of native bees are
solitary nesting bees. Bees visit flowers to get pollen and/or nectar, which they use to feed themselves and their offspring. Solitary bees nest in a variety of places
including dead trees, dirt mounds and termite holes.
Bumblebees are the exception as they live in social colonies. They need a bigger space for nesting, which can be above ground, in hollow trees or
walls, or below ground in an abandoned rodent hole. So don't be too quick to make your yard neat and tidy, destroying potential homes for native bees.
Many of you have heard of Colony Collapse Disorder, the condition that was found in the early spring of 2007. Thousands of honeybee hives that seemed
healthy in 2006 were found empty or full of dead bees after the winter. This is a problem, mostly for commercial bee-keepers who truck their thousands of hives from Texas to
New Mexico, Nevada, California, Oregon and Idaho following successive crops that need the help of bees for pollination. Colony Collapse Disorder is still not fully
understood, but some theories include bee exhaustion from the stress of traveling far distances and poor diet from gathering pollen and nectar from only one plant crop at a
time, rather than getting nutrients from a wide variety of plants every day.
Honeybees have long gotten most of the credit for pollinating in your vegetable garden, but native bees have always been important for pollinating
tomatoes, eggplant, melons, zucchini, winter squash, strawberries, raspberries and blueberries. Honeybees are not native to the United States, arriving in the 1600's with
English and Dutch settlers, and later with Spanish priests in Mexico and the Southwest. Farmers love honeybees because they live in hives which are easily portable, and
contain thousands of eager workers. Native bees are the under-appreciated local talent.
There are various ways to attract native pollinators wherever you live:
- Offer a flower buffet. Planting a variety of flower types and colors attracts and supports the biggest variety of native pollinators. Include
native wildflowers. Go to a local garden center where many flowers are in bloom. Buy the plants that have the most bees on them.
- Concentrate on perennials. Many annuals are hybrids, bred for show, not for nectar and pollen.
- Plan a continuous, three-season bloom. Different bees have different life cycles and need food at different times of the year.
- Plant large clumps of each flower type. One here and one there does not attract bees well.
- Add water if you don't have a natural source in your yard. A bird bath or drip irrigation hose provides clean water for bees.
- Leave bare ground. Most native bees live alone in the ground and need to dig their own nest tunnel. Plastic weed barriers and heavy mulch are
habitat destroyers for them.
Read other articles on birds, bees, & beneficial insects
Read other articled by Cathy Olson