Attract Pollinators to Your Garden

Posted on February 18, 2013 by tomkarwin

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.

The Xerces Society

Melissa Garden

Attracting Pollinators to Your Garden Using Native Plants

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.

Gardening for the Future

Posted on December 22, 2012 by tomkarwin

During a period of cold and rainy days, and holiday season attractions (and distractions), it may be difficult to focus on gardening priorities and attend to necessary tasks. On the other hand, this could be a very good time to plan future directions.

In this column, we consider resolutions for the coming year.

Our resolutions often address immediate needs, e.g., weeding in a more timely and consistent manner, upgrading the landscape design, removing a tree or shrub that has evolved from asset to liability, or installing a long-overdue drip irrigation system.

Each avid gardener could develop his or her own list of resolutions that are certainly worthy and not to be dismissed. Today’s goal is not to discourage productive actions but to suggest the importance of the long view.

This column is inspired by a recent report that chemical pesticides are used more extensively in the United States now than ever before. See below for a link to “Pesticides: Now More Than Ever,” by Mark Bittman, New York Times, December 11, 2012. The author cites research evidence of the link between pesticide exposure and certain cancers and other health problems and negative impacts on the environment, and states that genetically engineered crops are leading to dramatic increases in the use of pesticides.

These data are particularly troublesome, given the recent defeat of a state proposition to label genetically modified organisms (fruits, vegetables and meats). This proposition lost 47% to 53%, when multinational food corporations spent $46 million in a campaign that claimed falsely that the proposition was “flawed” and would be costly to consumers. The Organic Consumers Association, an advocate of that proposition, points to several similar initiatives in other states, begins preparing for another vote in California, and insists it is only a matter of time before GMO labeling becomes law.

Residential gardeners can resolve to support reduced uses of chemical pesticides by applying only organic methods in their own gardens, buying organically grown groceries and supporting the labeling of GMOs, when another vote is scheduled.

So-called “conventional” gardening, which relies upon chemical fertilizers and pesticides, was introduced in the early 1940s, during World War II. Americans are only beginning to recognize its threats to human health and the environment.

Organic gardening methods originated hundreds or even thousands of years ago. These methods are attuned with nature, inexpensive to apply, and proven to be effective.

For more satisfying gardening in the short term, a good resolution is to bring new-to-you plants into your garden regularly. Countless options are available in garden centers, catalogs and websites. New horticultural treasures can add learning opportunities and rewarding experiences to your gardening activities.

If you think that pesticides are simply a good thing in the garden or the agricultural field, read “Pesticides: Now More Than Ever,” by Mark Bittman, New York Times, December 11, 2012.

For a good introduction to organic gardening methods, read Organic Gardening magazine which is available from magazine stands or the Organic Gardening website. This publication has been a leading advocate of this natural approach to gardening for decades. It offers its magazine, online information and several authoritative books from various publishers. Rodale’s Ultimate Encyclopedia of Organic Gardening is a classic in the field.

Guidance in purchasing organically grown foods is available from The Daily Green, which lists “The Dirty Dozen” (foods with the highest pesticide residue), beginning with apples. When these foods are grown with so-called “conventional” methods, they will have relatively high concentrations of pesticides. If you want to eat these foods, buy only produce that has been certified as organically grown. Federal regulations require that foods that are labeled as “organic are grown without the use of pesticides.

Consumer demands to label genetically modified organisms are sure to continue on a state-by-state basis, until such initiatives force federal requirements for such labeling.To follow the political battle, visit the website of the non-profit Organic Consumers Association. This is one of several organizations that are pressing this issue, with determination to succeed in the long run.

The Organic Consumers Association seeks to persuade the Natural Products Association to stop calling GMOs “natural.” The term “natural” when applied to foods has no federal definition or standard and should not be mistaken for “organic” foods.

Gardener’s Gold

Posted on November 24, 2012 by tomkarwin

If you have deciduous trees in your garden, you might be fretting these days over the task of raking and disposing of the fallen leaves. You might instead welcome this form of nature’s bounty, because your trees have contributed the raw material for an excellent natural resource for your garden: leaf mold.

Leaf mold, which is simply partially decomposed leaves, can be used as a mulch to discourage weeds, retain moisture and insulate the roots of plants from the coldest weather. It can also be used as a pH-neutral soil amendment, like compost, to retain moisture, improve soil texture, add nutrients and support the growth of beneficial soil organisms of all kinds.

The question, then, is how to convert the fallen leaves to leaf mold.

The raking can’t be avoided, but the rest of the task could take any of several forms, depending on the gardener’s patience and available space, and the kind of leaves. Some leaves, including oak and holly, contain relatively high levels of cellulose and are slower to break down.

The easiest conversion of leaves to leaf mold is to pile the leaves in an out-of-the-way location and let them decompose on their own schedule. This process could require a year or more, but could be hastened in several ways, singly or in combinations.

Leave your leaf pile in a shaded location, or cover it with a plastic tarp. This helps to retain moisture, which supports the decomposition process, which depends upon the work of fungi.
Water the leaf pile occasionally, to maintain a damp (not soggy) condition.
Turn the pile occasionally, to expose the contents to oxygen.
Shred the leaves. Smaller pieces have greater exposure to the air and moisture, and therefore break down faster. Run over the leaves with a lawn mower—almost any kind would do—or put them through an electric leaf shredder or leaf blower-vacuum. My American Sycamore’s big leave tend to block my blower-vacuum, so they have to be roughly shredded first with the mower. For smaller quantities, place the leaves in a trashcan and shred them with a weed whacker. n order to keep your yard in tip-top shape and to protect your lawn from succumbing to the cold snow, you need to ensure that you take the proper steps to ensure that your lawn can spring back in the spring! Consider shoppok – cyclone rake the cost of this product in this site is better than other places.
Add nitrogen. Old dry leaves are almost all carbon, so the addition of nitrogen will speed their breakdown. Add green vegetation or nitrogen-rich fertilizer. Dry chicken manure has twice the nitrogen content as horse or steer manure.

The leaf mold is ready when it has become soft and crumbly. Use it to mulch your plant, spreading it about three inches deep (not too close to the base of the plant). Or dig a similar amount into the soil; this could be easiest when preparing a new bed, and is particularly helpful for improving soil that contains an excess of clay or sand. Leaf mold also could be included in containers to lighten their weight.

Enjoy gardener’s gold in your garden!

Mulch for Much Easier Gardening

Posted on September 8, 2012 by tomkarwin

Mulching represents a gardener’s not-so-secret strategy for achieving the universal objective: a low-maintenance garden.

If your garden is time-consuming, frustrating and disappointing, it probably needs mulching.

Several other possible causes should be considered: nutrient-poor soil, lack of irrigation, inappropriate plant selection, etc., but let’s focus for the moment on mulching.

A three-inch deep layer of an organic mulch between plants discourages weed growth, conserves water and, in time, breaks down to add nutrients and texture to garden soil.

We should not ignore the downsides of mulching. For example, a larger garden will require several cubic yards of organic mulch, leading to significant charges from a landscape supply company for the material and its delivery. In addition, distributing the mulch within the garden, while not difficult, consumes time and energy.

One more downside: organic mulches decompose in time, so the time and expense will have to be incurred again. Finer mulch materials break down faster than coarse materials.

Some organic mulch is free, e.g., disease-free wood chips that tree services will dump on your property, upon request (to avoid landfill charges), or seaweed harvested during low tide. Wood chips might be regarded as less attractive than finer mulches, and seaweed, although excellent in nutrient content, often is troublesome to gather, buddy and smelly.

A landscape supply company will offer a variety of organic mulches in bulk, e.g., redwood sawdust, shredded cedar, fir bark and gorilla hair (shredded redwood bark, really), in a range of sizes and prices.

Another option is cocoa shell mulch, which is available in bags of two cubic feet for about $5.00. This material looks good, emits a nice fragrance and breaks down slowly, but contains theobromine, a natural compound that if eaten is highly toxic to dogs and cats.

The gardener could consider each of the available options, and perhaps try a sample bag in the garden.

Home supply stores offer organic mulches in bags of two cubic feet of material. These can be appropriate for smaller beds, but for larger projects will be more expensive than bulk materials. To move one or two yards of mulch, it’s good to have a friend with a pickup truck.

Gravel mulch might be preferred for a rock garden or succulent garden. For a rock garden in particular, gravel mulch simulates scree, the debris of broken rock seen on mountain slopes.

Like organic mulches, gravel mulch discourages weeds, conserves moisture and looks better than bare soil. Gravel is much more expensive per cubic yard than organic mulches, but a one-inch layer should be enough and gravel doesn’t decompose. Gravel mulch is difficult to remove, so for practical purposes treat the installation as permanent.

Enjoy your mulched garden.

Estimating Mulch Needs

To decide how much material you will need, estimate the surface area of the garden bed(s) to be mulched: length times width (in feet). Multiple by the intended depth of the mulch layer: for a three-inch layer, multiply by .25. Finally, convert cubic feet to cubic yards by dividing by 27.

Example: a 12 feet x 18 feet garden bed has a surface area of 216 square feet. For a three-inch layer of mulch, .25 x 216 yields 54 cubic feet. Divide by 27 to determine a need for two yards of mulch.

Seaweed Mulch

An interesting article, How to Use Seaweed to Mulch Your Garden, is available on the website for Eartheasy: Solutions for Sustainable Living. Gardeners who live close to the beach might wish to try this mulch material, but it seems too smelly and buggy for my taste. It also decomposes into slime rather quickly.