Commercial Mulches and Organic Matter
Homemade compost and mulches from yard clippings and kitchen wastes are an out-and-out plus. But when you purchase these materials, it gets more complicated. First of all, there is the energy used to ship these heavy items to you. And there are other issues. Peat moss consists of mined plant debris from Canadian wetlands. Although the peat industry restores the bog after harvest, it takes at least a quarter century to regrow; in the mean-time, habitats are lost. In Florida, cypress tree habitats are logged solely to make cypress mulch.
None of us want toxic materials in our soils, and when you grow edible plants, you need to be especially careful. While you shouldn’t be paranoid, caution is warranted. Shredded recycled tires, in my opinion, have no place in any landscape, especially an edible one, as there are toxicity issues; besides that, they do not break down readily, nor do they add any organic matter to the soil./ Recycled wood mulch needs to be free of toxins. For help avoiding some chemicals when you buy mulch and potting soil, look for the Mulch and Soil. Council certification symbol on a package; it guarantees that no recycled lumber treated with CCA (Chromate copper arsenate, used for years in pressure-treated wood) is in the material. The Council also encourages companies to use sustainable forest practices. For more information, visit www.mulchandsoilcouncil.org.
If your soil needs serious remediation or large amounts of organic matter, look for bulk organic materials, such as grape pomade, mushroom compost, pecan and peanut hulls, or sawdust, that are recycled from local industries. Or if your municipality recycles yard wastes—and if you can be assured the composted material is free of herbicides, weed seeds, and plant diseases—it can become a great resource, as well.
Soil nutrients are another complex issue made simpler if you compost, and simpler still if you have a worm bin or keep chickens or rabbits. If you need to purchase a product, I recommend buying organic fertilizers, not artificial commercial fertilizers (which are made from non-renewable sources and contain salts that kill the life in the soil).
New organic products are introduced all the time. Caveat employ still applies: let the buyer beware. Most products are not regulated. Read labels carefully, especially the contents; check out both the active and inactive/inert ingredients listed. “Earth friendly” and “Natural” are marketing terms, not anything certifiable, and just as meaningless as when they are used on food packages. When in doubt, look for the OMRI (Organic Materials Review Institute) designation on packaging or go to www.OMRI.org to get a list of vetted materials.
Think twice before purchasing greensand or granite dust since they are mined products that are heavy to ship; often there are local equivalents. Plus greensand or granite dust since they are mined products that are heavy to ship; often there are local equivalents. Plus greensand is not appropriate in alkaline soils. Fertilizers made from recycled municipal sewage sludge have their advocates. I can’t deny that we need to recycle sludge, but I’ve worked on studies that occasionally found heavy metals, drugs, and esoteric solvents in a few batches. To be safe, I don’t use it in my edible gardens. While we once used ground oyster shells to neutralize alkaline soil, they have a more valuable purpose in coastal areas—dumped into
the bays to create new reefs for oysters to breed.
For centuries wood has been a mainstay in the garden- from trellises and arbors to benches and chairs, not to mention containers and window boxes. More recently wood has been used on a larger scale for decking and building raised beds. Even when treated with chemicals or painted, wood disintegrates with time: the added stress from sun, rain, and contact with wet soil hastens its demise.
America’s constant need for wood products has put pressure on forests all over the world. Two solutions have been tried: plantation forests, where the trees are replanted in vast monocultures, and certified sustainable timber, in which renewable methods are used to help maintain habitat. Neither is perfect. Plantations provide only minimum biodiversity, and the certification process for lumber is complex, expensive, and especially hard on developing nations. When you buy wood, ask for the FSC label of the Forest Stewardship Council or the Smartwood- Rediscovered Wood Certificate. Go to the Rainforest Alliance website for more information on wood products: www.rainforest-alliance.org.
You can also grow and use timber bamboo in place of some wood for plant stakes, furniture, and lath; it is sustainable. Recycled plastic has entered the marketplace as another wood alternative- for fences, arbors, trellises, decking, and lumber.
Reducing Light pollution
As you fly over urban areas at night, it’s hard not to notice all the bright lights stretching across the horizon. Most of them are streetlights and commercial site lighting, but the landscaping lights around homes are contributing more and more to that pervasive glow. Astronomers were the first to be aware of light pollution, and stargazers must now travel far away from populated areas to see into the heavens.
Scientists have learned that millions of nocturnal insects and small animals are either drawn to these nighttime lights and perish or avoid the lights and stay hidden instead of feeding or looking for a mate. The light throws migratory birds off course and disrupts the mating rituals of fireflies and moths. It can even disturb the democracy cycle of trees. According to the International Dark- Sky Association, wasted light across America uses up to 30 million barrels of oil every year. Many homeowners install permanent security lights and keep them on all night, even though research shows that motion- activated lights not only save energy but are a better crime deterrent. For the environment, the worst culprit in the home landscape is uplighting, which sends its rays unnaturally upward to highlight a tree, fountain, or other feature. For more information, see “Outdoor Lighting” in chapter 3 and visit www.darksky.org.
I’m adamant about reusing and repurposing materials. For decades as a landscape designer, I’ve had my contractors reuse the tops of fence posts in retaining walls and broken concrete as stepping- stones. The crew brings me leftover pavers, which I use when redesigning my garden. I also scavenge. My short grape stake fence was once my neighbor’s taller fence. My favorite red bench had been abandoned, one leg broken, on a curb; I rescued it from the maw of a garbage truck.
Now, as my grandmother would say’ I’m going to get on my high horse and rant about something- namely, plastic. With all those recycling symbols stamped on plastic products and handy recycling bins supplied to us, I was lulled into thinking that we’d made great progress in recycling plastics. As it turns out, the plastics industry is anything but clean and green. The landmark 1996 report of the Berkeley Plastics Task Force raised a number of unsettling issues that we still need to address:
- Making plastics from natural gas and oil contributes 13 percent of America’s toxic fumes.
- Most of our used plastic is shipped to poor countries in Asia to be sorted and melted down under conditions that would give an EPA inspector nightmare.
- Plastic cannot be melted down more than once or twice, so it will still eventually live indefinitely in landfills, along roadways, or as ocean flotsam. (The world’s largest “seafill,” called the Great Pacific Garbage Patch- filled with plastics in many forms and sizes and covering an area twice the size of Texas- is rotating in the waters of the northern Pacific Ocean.)
- The chasing arrows symbol on the plastic packaging pacifies us into thinking that when we “recycle” plastic, it is recycled. Yet there is no market for many of the numbered plastics, so those products are sorted out and sent to the landfill.
The obvious solution is never to buy plastic, but that’s next to impossible. So, what to do? Whenever possible, I try not to purchase anything made of or packaged in plastic, but even eco-friendly hydrolyzed fish comes in a plastic bottle. Buy your garden products in bulk, such as a truckful of soil, or in the largest package size available. Choose concentrates over diluted solutions. Try not to buy new plastic. Instead, look for garden products like TerraCycle organic fertilizer- as the company says, “we sell waste(liquefied worm poop) packaged in waste( used plastic soda bottles)”- and garden furniture that contains a larger percentage of recycled plastic, so at least you help create a market for recycled plastic. Support nurseries and garden centers that recycle pots or, even better, sell plants in containers that will break down in your compost pile.
Since more and more home gardeners are now embracing organic products and methods, major suppliers are scrambling to bring recycled products to market, and dozens of companies now offer green building materials.