Synthetic chemicals have a variety of garden uses: adding nutrients to the soil (or directly to plants), discouraging/killing harmful insects and other small pests, and protecting plants from viruses, fungi and other scourges.
These benefits, however, come with downsides, including destroying microorganisms in the soil and beneficial insects, accumulating salts in the soil, and harming (or worse) pets and gardeners themselves. And there’s more, too much to review in this column.
Our present focus is on the harm that synthetic chemicals bring to insect pollinators: honeybees, native bees (which are different) and butterflies. Concerned scientists and citizen scientists have recorded significant population declines among these pollinators, and have pointed to pesticides as the likely cause of these declines.
Our gardens need these pollinators. They are essential in sexual reproduction of plants, including the development of fruits, vegetables and berries, all of which bear seeds, and both natural and human-directed hybridization of plants.
There are also asexual forms of plant reproduction, to be sure, but we’re concerned here with the pollinators.
The first priority in attracting pollinators to your garden is to adopt organic gardening methods, i.e., no synthetic chemicals. Safe organic products are available to address any gardening need, and integrated pest management (IPM) strategies work better and cheaper in the long run than the quick fixes of synthetic chemicals.
The next important priority is to plant more flowers as food resources for bees and butterflies. An excellent resource this subject is The Xerces Society for Invertebrate Conservation, a non-profit organization. The Society offers reliable information on all aspects of attracting pollinators.
The Society’s guidelines for California gardeners get to the point:
- Use local native plants (bees prefer them);
- Choose several colors of flowers (blue, purple, violet, shite and yellow are good; pink and red not so much);
- Plant flowers in clumps (a four-foot wide clump of one flower is much better than a scattering of the same number of plants);
- Include flowers of different shapes (bees come in different sizes and different preferences);
- Have a diversity of species flowering all season (both the bees and you will appreciate having flowers for most of the year).
Another helpful resource is The Melissa Garden: A Honeybee Sanctuary, which is located in Sonoma County. The owners offer an extensive list of plants that attract bees, and offer tours and classes in beekeeping, attracting pollinators, and related topics. “Melissa” is from the Greek word for honeybee.
Visit ongardening.com for links to The Xerces Society, the Melissa Garden and other resources for attracting pollinators to your garden, as well as for information on organic gardening and integrated pest management.
As you add flowering plants to your garden, choose some for the bees and butterflies.
Organic Gardening: There are many books and magazines on this subject. A classic in the field is Maria Rodale’s Organic Gardening: Your Seasonal Companion to Creating a Beautiful and Delicious Organic Garden (Rodale Press, 1998)
Integrated Pest Management The University of California’s Integrated Pest Management program is a valuable resource for California gardeners. Another useful resource is the U.S. Environmental Protection Agency’s webpage on IPM Principles.