I have heavy clay soil that becomes as hard as a brick when it dries, and my neighbors who also garden have asked me how to improve clay soil. What are the best methods for improving clay soil?
First, the good news: “Of the three major soil components — sand, silt and clay — clay has the highest nutrient content,” says Garn Wallace, president of Wallace Labs, a soil-testing firm in El Segundo, Calif. Clay soils retain minerals in forms that are readily available to plants and that aren’t water soluble, so rain and irrigation water are less likely to leach them away. The trouble is that clay lacks good porosity. Its fine-textured particles tend to clump tightly together. Air, water, roots and seedlings can have trouble moving through it, so crop yields may be lower. (Plus, clay is a pain to work in!)
Increasing your soil’s organic matter is the first and most important step toward improving heavy clay soil. Organic matter invites in more porosity-improving earthworms. Work in compost, grass clippings, shredded leaves or other organic materials. Plant and turn under cover crops, and safeguard your soil’s surface with an organic mulch to prevent crusting. Sand or peat moss can also improve soil texture, but they lack many of the other benefits of organic matter, such as beneficial microbial activity and nutrients for your plants to uptake. Plus, you’ll need a lot of sand to make a real difference (1 part sand to every 2 parts clay soil).
Photo by Dreamstime/Ian Nixon: Don’t be foiled by your heavy clay soil: Add organic matter to soften up your tough terrain.
Vicki Mattern is a contributing editor for MOTHER EARTH NEWS magazine, book editor and freelance magazine writer. She has edited or co-authored seven books on gardening, and lives and works from her home in northwestern Montana. You can find Vicki on Google+.
I need to tear down an old deck and I think it may be made of treated wood. How should I dispose of it?
For many years, most outdoor structures were built with pressure-treated wood that had been soaked in chromated copper arsenate (CCA). This pressure-treated wood contains arsenic, chromium and copper, minerals that do not biodegrade and are toxic to soil life.
You should never burn this wood outdoors or in a stove or fireplace; the ashes can be deadly to livestock and humans. Knowing for certain whether wood is treated with CCA is difficult, but CCA was common in decks, fences and other outdoor structures, so you should assume that wood installed outdoors before 2004 contains CCA. In 2004, manufacturers were finally forced to stop selling CCA-treated wood for residential uses, and less-toxic treatments have since replaced much CCA.
You should take any unwanted treated wood to your local landfill or transfer station and place it in the designated location.
Above: Knowing for certain whether wood is treated with CCA is difficult, but CCA was common in decks, fences and other outdoor structures, so you should assume that wood installed outdoors before 2004 contains CCA.
Photo By Fotolia/alexvav
I’ve heard mulches made from ground-up tires could be toxic. Is rubber mulch safe to put on my garden beds?
Rubber mulches made from shredded tires are touted by manufacturers as permanent, aesthetically pleasing, and safe for flowers, plants and pets. Companies assert that the mulch material is an environmentally friendly solution to a major waste-disposal problem. But scientific literature makes abundantly clear that rubber should not be used as a landscape amendment or mulch. There is no question that toxic substances leach from rubber as it degrades, contaminating soil, plants and waterways.
The toxicity of rubber leachate is mainly a result of its mineral content: Aluminum, cadmium, chromium, copper, iron, magnesium, manganese, molybdenum, selenium, sulfur and zinc have all been identified in laboratory and field leachates. Of those minerals, rubber contains very high levels of zinc — as much as 2 percent of the tire mass. If rubber products have been exposed to contaminants, such as lead or other heavy metals, during their useful lifetime, they will absorb those metals and release them as well. A number of plant species have been shown to accumulate abnormally high levels of zinc, sometimes to the point of death. U.S. Department of Agriculture researcher Rufus Chaney, who has studied zinc and other metals in soils and plant materials for decades, strongly believes that ground rubber should not be used in any compost, potting medium, or agricultural or garden soils because of zinc toxicity. Acidic soils and aquatic systems are particularly sensitive because heavy metals are less tightly bound to the soil and thus more available for plants and animals to uptake.
Rubber mulches can also leach various plasticizers and accelerators that are used during tire manufacturing. In high enough concentrations, some of these rubber leachates are known to be harmful to human health; effects of exposure range from skin and eye irritation to major organ damage and even death. Long-term exposure can lead to neurological damage, cancers and mutations.
Some of the toxic materials in rubber break down quickly, while others bioaccumulate. One common rubber leachate is 2-mercaptobenzothiazole, a chemical commonly used as an accelerator during the production process. In addition to its known human health effects, it is highly persistent in the environment and acutely toxic to aquatic organisms — its environmental persistence may cause long-term damage to aquatic environments constantly exposed to rubber leachates.
Another family of organic leachates under scrutiny are the polyaromatic hydrocarbons (PAHs). These compounds, used as rubber softeners and fillers, have been repeatedly demonstrated to poison aquatic life. After two years in a laboratory test, PAH leachates were shown to be even more toxic than at the study’s inception.
According to the Environmental Protection Agency, we generate 290 million scrap tires annually, and scrap tire stockpiles pose significant fire hazards. Obviously, we need to find a safe way to recycle these slow-to-decompose materials, but using shredded tires as mulch to spread over our gardens and playgrounds is not a wise choice. A better alternative is to increase the use of shredded tire rubber in asphalt for roadways.
Linda Chalker-Scott is an Associate Professor and Extension Urban Horticulturist at Washington State University’s Puyallup Research and Extension Center. Read more of her work on the blogs The Informed Gardener and The Garden Professors. You can also find The Garden Professors on Facebook.
Can you recommend a reputable company or website that sells non-GMO, organic garden seeds?
So far, only a handful of common garden crops have been genetically engineered, and, as far as we know, no garden seed companies are knowingly selling genetically modified (GM) varieties at this time. Additionally, many garden seed companies sell Certified Organic seeds, and the certification rules prohibit genetic modification. Even if new GM varieties enter the market, as long as you choose Certified Organic garden seeds, you’ll be avoiding genetically modified organisms (GMOs).
Two mail-order companies that offer only Certified Organic seeds are High Mowing Organic Seeds and Seeds of Change. Certified Organic, GMO-free seeds are usually labeled as such in seed catalogs and on racks.
When choosing where to buy non-GMO seeds, you can also turn to companies that have signed the Safe Seed Pledge. This pledge is maintained by the Council for Responsible Genetics, and the companies that sign it promise not to knowingly sell GM seeds.
Unlike garden seeds, major farm crops — corn, soybeans, canola, sugar beets, alfalfa and cotton — are now predominantly GM, and 70 percent or more of foods in supermarkets directly or indirectly contain GMOs. For tips on how to forgo GM products in your everyday food purchases, read How to Avoid Genetically Modified Food.
Photo courtesy High Mowing Organic Seeds: All offerings from High Mowing Organic Seeds are Certified Organic.
Cheryl Long is the editor in chief of MOTHER EARTH NEWS magazine, and a leading advocate for more sustainable lifestyles. She leads a team of editors which produces high quality content that has resulted in MOTHER EARTH NEWS being rated as one of North America’s favorite magazines. Long lives on an 8-acre homestead near Topeka, Kan., powered in part by solar panels, where she manages a large organic garden and a small flock of heritage chickens. Prior to taking the helm at MOTHER EARTH NEWS, she was an editor at Organic Gardening magazine for 10 years. Connect with her on Google+.
I often hear that I need to eat antioxidant-rich foods. What are antioxidants, and how do they work?
Antioxidant molecules in our bodies inhibit the oxidation of other molecules and neutralize “free radicals,” or unstable compounds. Free radicals are created by oxidation, a chemical reaction involving the loss of electrons in a molecule. More familiar examples of oxidation are butter going rancid, iron rusting, apple slices browning and fires burning. Apply antioxidant-rich lemon juice to your sliced apple, and what happens? The flesh will resist browning.
Free radicals accelerate aging and contribute to many chronic illnesses, including Alzheimer’s disease, arthritis, atherosclerosis, cancer, cardiovascular disease, cataracts and diabetes. To stabilize themselves, free radicals snatch electrons from other atoms or molecules, which can then spark a chain reaction of electron raiding.
While the body’s free-radical production is normal and sometimes even useful, an overload of oxidation can damage molecules, such as DNA, fats and proteins, thereby disrupting cell functions. In addition, oxidation stirs up inflammation, which generates more free radicals.
Other conditions heighten free-radical formation and oxidative stress: tobacco smoke, certain forms of pollution, fever, infection, chronic inflammation, chronically elevated blood glucose (diabetes), ultraviolet light and radiation, extreme exercise, and consumption of unhealthy hydrogenated fats, such as trans fats and oils in fried foods.
Many normal bodily processes create free radicals, such as when our bodies break down nutrients for energy, fight off infection or detoxify drugs. But the body also produces its own antioxidants to neutralize free radicals — a process that works well until an excess of free radicals overwhelms the system.
Eating antioxidant-rich foods can restore the balance. Animal products contain some antioxidants, but your richest sources are plants, which contain antioxidants such as vitamin C, vitamin E, selenium, carotenoids and flavonoids.
Carotenoids and flavonoids double as plant pigments, so eat a variety of colorful fruits and vegetables, as well as culinary herbs and spices, to maximize your dietary antioxidants. Particularly rich sources include berries, cherries, red grapes, papaya, pumpkin, carrots, green tea, garlic and cruciferous vegetables, such as broccoli, cabbage and kale.
Now that you know how antioxidants work in your body, learn more about building a diet around them by reading The Best Antioxidant-Rich Foods for a Disease-Fighting Diet.
Photo by Dreamstime/Maffboy: Eat your colors! Vividly hued foods, such as these bright berries, are rich in antioxidants.
I want to feed the birds that visit my backyard, but I’m not sure what types of seed to set out. What do birds like best?
Different birds are attracted by different kinds of seed, so offering a variety will beckon a diverse mix of feathered friends. Just make sure the birdseed or food you choose is compatible with both the bird feeder and the birds you hope to attract.
Sunflower seeds. Many small birds prefer black oilseed, especially in northern latitudes. Large-beaked birds will eat striped sunflower seeds. Hulled sunflower seeds will appeal to the greatest variety: They will attract jays, red-bellied woodpeckers, finches, goldfinches, Northern cardinals, evening grosbeaks, pine grosbeaks, chickadees, titmice, nuthatches and grackles.
Millet. Most small-beaked ground-feeding birds love white and red millet. Both will attract quail, doves, juncos, sparrows, towhees, cowbirds and red-winged blackbirds.
Cracked corn. Medium cracked corn is about as popular with ground-feeding birds as millet, but it’s vulnerable to rot because each kernel’s interior easily soaks up moisture. Leave small amounts mixed with millet on feeding tables or in watertight hopper feeders. Avoid fine cracked corn because it quickly turns to mush, and coarse cracked corn because it’s too large for small-beaked birds. Medium cracked corn will attract pheasants, quail, doves, crows, jays, sparrows, juncos and towhees.
Milo, wheat and oats. Low-priced birdseed blends typically include a mixture of these agricultural grains. Most birds discard them in favor of other food, however, which then leaves the grains to accumulate under feeders and attract rodents. Ground-feeding birds in the Southwest will eat milo, as will pheasants, quail and doves.
Thistle (nyjer). A preferred food of American goldfinches, lesser goldfinches, house finches and common redpolls, nyjer is sometimes called “black gold” because, at about $1.50 per pound, it’s more expensive than other birdseeds.
Suet. Otherwise known as beef fat, suet will attract insect-eating birds, such as woodpeckers, wrens, chickadees, nuthatches and titmice. Place the suet in special feeders or net onion bags at least 5 feet above the ground to keep it out of the reach of dogs. Suet is particularly helpful during cold weather and migration, when birds need extra fat reserves, but you can also purchase “no-melt” suet cakes for use in warmer weather. To learn how to make your own, read How to Make Cakes for a Suet Bird Feeder.
Peanuts. Placed in tube-shaped, metal-mesh feeders, peanuts will entice woodpeckers, jays, chickadees, titmice, bushtits, nuthatches, brown creepers, wrens, kinglets, Northern mockingbirds, brown thrashers, starlings, and yellow-rumped and pine warblers.
Peanut butter pudding. Peanut butter is a good substitute for suet. Mix 1 part peanut butter with 5 parts cornmeal, and stuff the mixture into holes drilled into a hanging log or into the crevices of a pine cone. It will attract woodpeckers, chickadees, titmice and occasionally warblers.
Fruit for berry-eating birds. Fruit specialists, such as robins, waxwings, bluebirds and mockingbirds, rarely eat birdseed. To attract them, soak raisins and currants in water overnight, drain, and then place on a table feeder. You can also purchase birdseed blends with a dried fruit mixture. To attract orioles and tanagers, skewer halved oranges onto a spike near other bird feeders, or provide nectar feeders.
Nectar for hummingbirds. Make an artificial nectar of 1 part sugar to 4 parts water. Boil briefly to sterilize and dissolve sugar crystals. You must keep the feeders scrupulously clean to prevent mold growth.
To learn more about bird habitats, bird conservation and what to feed wild birds, check out the National Audubon Society online.
Photo by Bruce McGlenn: Bring a bevy of birds to your backyard by knowing which seeds will satisfy.
I found out the hard way that my garden is infested with poison ivy. What should I do to evict this rash-causing weed?
Getting rid of poison ivy in your yard is tough — there’s just no easy way to do it. One of the most effective techniques to banish it is to pull it and pull it and pull it. Wear special gloves that you never use for anything else and use a pair of long-handled pliers. The ivy’s stems run mainly near the surface of the soil and up onto nearby trees. Large lengths will come up when you pull. If the stems are thick and won’t budge, then you’ll have to cut them and paint the remaining portion with an herbicide. Repeat this pulling process as needed each year.
Before you begin pulling poison ivy, apply the FDA-approved product called Ivy Block to your hands and arms to protect your skin. After you’re finished, carefully remove your gloves, wash your clothes, and wash your hands with Tecnu Extreme Medicated Poison Ivy Scrub. You can find these products online or at a drugstore.
Photo by Dreamstime/Stevebrigman: Pesky poison ivy often likes to climb up trees.
Cheryl Long is the editor in chief of MOTHER EARTH NEWS magazine, and a leading advocate for more sustainable lifestyles. She leads a team of editors which produces high quality content that has resulted in MOTHER EARTH NEWS being rated as one North America’s favorite magazines. Long lives on an 8-acre homestead near Topeka, Kan., powered in part by solar panels, where she manages a large organic garden and a small flock of heritage chickens. Prior to taking the helm at MOTHER EARTH NEWS, she was an editor at Organic Gardening magazine for 10 years. Connect with her on Google+.