Testing for 5 Key Compost Characteristics »

by Organic Gardening staff

We tested 30 brands and found that it’s a mixed bag.

We asked Will Brinton, Ph.D., and the staff members of the Woods End Research Laboratory to test bags of compost from all regions of the United States. Products included composts made from cow, chicken, horse, and sheep manure; used mushroom “soil” and food wastes. The lab measured five key compost characteristics, and as you’ll see, many of the brands flunked several of the tests. (We didn’t include any products that contained sewage sludge, often labeled as “biosolids,” because we believe most sludge-based composts should not be used in home gardens due to probable contamination with toxic wastes and heavy metals.)

What We Tested: Organic Matter Content

Why it matters

Nitrogen is the nutrient that demands the most attention because it’s the most likely to be in short supply in your garden and because it’s also the nutrient most likely to cause pollution problems if it’s overapplied. The nitrogen content should be a key factor in determining appropriate application rates of compost.

What the tests showed

16 out of our 30 composts were too old or had been diluted with soil, resulting in an organic-matter content less than 30%. Although using them wouldn’t harm your soil, they were definitely not good buys. Only a third of our samples fell within the preferred range of 30 to 60% organic matter. Four products contained levels over 60%, indicating that they were probably not yet fully composted.

What We Tested: Content

May vary from 0.5 to 2% or more; should be indicated on the label if above 1%.

Why it matters

If the organic-matter level is over 60%, then the compost isn’t yet mature, and it could temporarily inhibit plant growth when mixed into the soil (although it could still be used safely as a surface mulch). If the level of organic matter is too low, then the compost simply won’t improve the soil as well as a better-quality product would. “Organic matter is the essence of compost,” Dr. Brinton explains. “It’s the energy source that feeds soil microorganisms and regulates the steady release of plant nutrients. It also creates the ‘glue’ that improves soil texture, and it increases the soil’s ability to hold moisture.” Should be 30 to 60%.

What the tests showed

Only one-third of the bagged composts listed the nitrogen content on their labels. But Dr. Brinton’s lab tests revealed that the producers were not using nitrogen content to set their recommended application rates. The rates provided on the bags were often too high. No labels made a distinction between annual rates and higher one-time rates for new beds.

What We Tested: pH

Should be in the neutral range, between 6.5 and 7.5.

Why it matters

pH is a measure of acidity or alkalinity, represented by a number on a scale in which 1 is very acidic, 7 is neutral, and 14 is extremely alkaline. For optimum plant growth, you want to maintain a nearly neutral soil pH in your garden. Regular applications of good-quality compost help maintain neutral soil pH, but you should avoid using overly acidic composts on soils that are already naturally acidic, and avoid high-pH products on already alkaline soils. (If you don’t know your soil’s pH, have it tested.)

What the tests showed

About half of our samples fell within the 6.5-7.5 pH range, nine were too high (as alkaline as 8.3), and four were too low (as acidic as 4.5). If you think a difference in pH of just one point or so probably doesn’t matter much, think again: the pH scale is logarithmic, which means that for each one-point change, the alkalinity (or acidity) increases or decreases by 10 times.

What We Tested: Carbonate

Levels Should be indicated when high.

Why it matters

Using an overly acidic compost won’t usually do any long-term damage to your soil, but using one that’s too alkaline might. High-pH composts often contain carbonates, usually in the form of lime (calcium carbonate.) If you have naturally alkaline soil (most common in drier regions) or if your soil is acidic and you already apply lime to reduce the acidity, Dr. Brinton warns that you should avoid using a high-pH compost. “Once a soil contains too much carbonate, other nutrients, such as phosphorus and zinc, will become unavailable,” he says. “And there is no easy way to bring the soil back into balance.” What the tests showed:
Dr. Brinton found that 30% of the composts had high carbonate levels, making them poor choices for use on alkaline or recently limed soils. And not a single compost producer had included information about carbonate levels on its label.

What We Tested: Salinity

Should not exceed 5 mhos/centimeter. (An mho is a unit used to measure salt conductivity.)

Why it matters

As organic matter decomposes, minerals are slowly converted to salts that dissolve in water and become available for plant roots to absorb. If compost production is not managed properly, or if a large amount of chicken manure is used, salts can sometimes accumulate to a level high enough to injure plants-especially seedlings. Low salinity is particularly important in dry regions, where soils are already naturally high in salts because there isn’t enough rainfall to leach the salts down into the subsoil. You should also choose a low-salt compost for heavy applications before direct seeding and for container mixes.

What the tests showed

25% of our samples exceeded the 5 mho/cm standard. And none of the compost products we evaluated listed the salinity level on the label.

What Our Inspections Revealed

Here’s what we found when we examined our bagged samples:

Texture:

One out of every four of the 30 brands we inspected contained compost that was so sticky and clumpy that it would have been impossible to spread in the garden. (I made a beautiful “clay” pot from one brand, while another dried into serviceable rock-hard bricks!) Several others were obviously too woody and not fully composted.

Color:

The color of all the brands was similar while the composts were moist, but when we dried them out for a few days, three of the brands were too light in color to be good-quality composts.

Moisture:

All of the the sticky composts-one out of every four-were too wet. Most others were appropriately moist. Only one product had a very low moisture content, and it was labeled as “Chicken Manure Fertilizer-dry, composted, will not burn.” We suspected a problem because of the product’s strong odor, and, sure enough, Dr. Brinton’s tests confirmed that the chicken manure was not fully composted.

Smell:

We found several brands that smelled sour or reeked of ammonia, indicating poor-quality immature products. Only one bag had that desirable earthy, woodsy smell when we first opened it, but several more developed the earthy odor after they had been exposed to the air for a few days.

Reprinted with permission from Organic Gardening Magazine

Buying Compost »

by Cheryl Long

The Good News and the Bad

We tested 30 brands and found that it’s a mixed bag.

Homemade compost is the best thing you can use to feed your plants, improve your soil, and recycle yard wastes. But it seems as if there’s never enough-no matter whether you’re starting a new bed, trying to cover your entire lawn, or living in an apartment and tending a community-garden plot. What’s a gardener to do?

The obvious answer is to head for the garden center or home-improvement store and load up the car with bagged compost. However, when we took a close look at what was in those bags, we discovered the bad news: Some brands tested well, but many flunked out. The good news is that there are simple steps you can use to select a top-quality compost product.

Our Testing Methods

We collected 30 bagged composts from stores across the country. Right away we saw that there was a problem with the labeling-or rather, with the lack of information on the labels-of every single bag. The recommended application rates on the labels varied widely, too-from 4 inches to only 1_10 of an inch. When we opened the bags, we were in for more unpleasant surprises. Several manure-based composts were so wet and gooey that they looked like brown Play-Do. A couple of the bags reeked of ammonia, which is a sure sign that they weren’t fully composted. And several more contained shredded wood and bark that were mislabeled as compost.

Then we sent the samples to compost expert Will Brinton, Ph.D., president of Woods End Research Laboratory in Mount Vernon, Maine. His lab tests revealed even more problems, including excessively acidic or alkaline composts, high salt levels, and improper application rates on the labels.

As we analyzed all this data, we discovered an easy way you can test compost quality right at home.

Be a Compost Connoisseur

Buying compost isn’t as simple as looking for the best brand. We can’t even give you a brand-by-brand comparison because most commercial composts are produced and sold locally; you won’t find the same products in South Dakota and Tennessee-or even in Nashville and Memphis. The quality of commercial composts varies because they are usually made from whatever local “waste” materials are available at the time; the contents will differ from batch to batch. (For example, one batch might be made with low-salt manure; the next, with high-salt.) That means that unless the producer monitors each batch carefully, a brand that tested at the top of the class this month might flunk out the next time.

Fortunately, a simple look (and sniff) can be all you need to do to find a good-quality product. Here’s how to check out the texture, color, moisture, and “bouquet.”

1. The texture should be loose and granular, with little or no recognizable wood or bark. If the compost isn’t loose enough for you to spread and work into your garden beds easily, don’t buy it. (See the photo on page 51 for examples of what to avoid.)
2. The color should always be dark brown or almost black in color. Avoid products that are light in color. They probably contain too little organic matter and too much soil. It’s easiest to tell the true color if you let the compost sample dry out.
3. Compost should be moist, not dry or soggy. One of compost’s biggest benefits, once it’s in the soil, is that it can hold up to 2-1/2 times its weight in water. But in bagged products, excess moisture makes the compost difficult to spread. It also means that if the compost is sold in 40-pound bags (as most of them are) and you buy a wet product, you’ll be paying for water, not compost. (Hefting a bag will give you a good idea of its moisture content. If it feels like a big glob, the compost is probably too wet; if it feels loose, it is probably drier.)
4. Ideally, mature compost will have a nice earthy smell, but this isn’t a reliable test for bagged compost-at least not right away. That’s because the plastic bags restrict the oxygen supply to the organisms that release the earthy odor. If you do find an earthy, woodsy odor, you’ve probably struck “black gold”-a mature, good-quality compost. Most bagged composts will probably have a slight musty or barnyard odor when you first open them, and that’s fine. Avoid any products that have a strong unpleasant smell (ammonia or sewer gas, for example) because the odor indicates an immature compost that might damage plants. If you don’t want to smell it, don’t put it on your garden.

(Some stores may not let you inspect a bag before you buy it. So if you buy a bag and find it’s not up to these standards, either take it back or dump it onto your home pile to dilute and fully compost.)

What Does It All Mean?

We started this project because we suspected there might be some poor-quality compost on the market, and we wanted to help gardeners buy the best possible products.

Until the compost industry cleans up its act, we recommend that you continue to make as much compost at home as you can and use it as soon as it decomposes to the point that you can no longer recognize the original ingredients. If you just can’t make as much as you need, head for your local yard-waste recycling center. At the one here at Organic Gardening magazine’s home base in Emmaus, Pennsylvania, city residents (including OG staff members) can pick up as much compost as their sagging vehicles can carry. It’s easy, it’s pure composted yard wastes, and it’s free!

If your city doesn’t have a yard-waste composting site, you can sometimes save money by buying compost in bulk from garden centers. Bulk composts are often cheaper than bagged products: 1 cubic yard of bulk compost (the equivalent of about 25 40-pound bags) usually costs under $30, whereas the good-quality bagged composts sell for $2 to $4 or more per 40-pound bag.
If you decide to buy bagged compost, inspect the contents carefully before you buy multiple bags. And if you need a large amount of compost, it’s probably worth your time to insist on seeing lab-test results so that you can check them against the quality standards outlined in “The Woods End Lab Report”. (Any reputable compost producer should have lab-test information available.)

Gardeners have a right to expect good-quality compost, fully tested and correctly labeled. Having informed consumers ask tough questions may be the only thing that will force the industry to improve. Years ago, farmers had to fight a long, hard battle to pass laws requiring that all fertilizers be fully labeled. Right now, compost producers can avoid those laws if they don’t call their compost “fertilizer.”

We hope you’ll use this special report to educate local suppliers about compost quality. If you find compost producers that are doing a better job of meeting quality and labeling criteria than those that created the products we surveyed for this report, we would love to hear about them. And if you obtain lab-test results to help you evaluate composts being sold in your area, please write to us and share what you have learned.

Reprinted with permission from Organic Gardening Magazine

Organic Weapons »

by Organic Gardening staff

Andy Jones and Erin Hanley, managers of Intervale Community Farm, produce bumper crops by using a full arsenal of organic techniques, many of which can be used in the home garden:

• Build soil tilth and fertility by applying generous amounts of compost.
• Plant legume cover crops, such as clover and vetch, to add organic matter and nitrogen to the soil.
• Use fabric row covers to protect crops from insect pests.
• Use BT (Bacillus thuringiensis) sparingly if necessary to control potato-beetle larvae.
• In cold climates, use a plastic-covered hoop house to give tomatoes an early start outdoors. Hoop houses also discourage soil borne diseases by preventing rainfall from splashing soil on the plants’ leaves.
• Nature hates a mono culture. Diversify and rotate crops to confuse insects and best use soil nutrients.
• Interplant flowers with vegetables to attract bees and other beneficial insects.

Reprinted with permission from Organic Gardening Magazine

New Do-It-Yourself Compost Test »

by Organic Gardening staff

Compost is the ideal soil conditioner because of its high organic-matter content: 30 to 60 percent. But we found that many bagged composts contained less than 30 percent organic matter (OM). As I studied our lab reports, I was amazed by the wide variation in the OM content of the brands. And I was frustrated that we didn’t have an easy way to help home gardeners assess this key characteristic of compost. So I decided to do a little compost testing myself-with some help from Woods End Research Laboratory.

I knew that compost gets heavier (denser) as it ages, so I asked Dr. Brinton to run some tests to see whether there might be a way to predict the amount of OM based on the variation in the weight of given volumes of dried composts. Sure enough, when I dried and weighed our samples and then Dr. Brinton ran my data through his computer, we found a nifty way you can easily get an good estimate of the OM content:

Spread out a shovel full of compost indoors on a thin layer of newspaper and let it air-dry for about a week. Then, measure out exactly 1 pint (2 cups) of the dried compost and weigh it. If it weighs from 8 to 12 ounces, then it contains the desired level of 30 to 60 percent OM. If it weighs less than 8 ounces, the compost is probably immature; if it weighs more than 12 ounces, it is too old or has been diluted with soil.

Reprinted with permission from Organic Gardening Magazine

How Much Compost Do You Really Need? »

by Organic Gardening staff

People get the idea that they need to bury their gardens under truckloads of compost to get good results; however, in most areas of the country, less than a half-inch-thick layer each year is plenty.

Nitrogen is the main nutrient you need to provide your plants. Most edible crops need an annual application of only about 11/44 pound of nitrogen per 100 square feet, and lawns and ornamentals need even less than that. In most regions, a yearly rate of just 1/2 inch of compost containing 1 percent nitrogen (about four 40-pound bags or 30 gallons per 100 square feet) will accumulate enough organic matter in the soil to provide ample nutrients for excellent plant growth. In the longer growing seasons of the South and in areas with very high rainfall, that annual rate should be doubled to 1 inch. For one-time applications to new garden beds, you can double or even triple the annual rate if you’re sure you have a good-quality compost.

Reprinted with permission from Organic Gardening Magazine

Homemade versus Store Bought…
What’s the Difference? »

by Organic Gardening staff

Unlike homemade compost, which comes from a mix of kitchen scraps, garden wastes, grass clippings, and leaves, commercial compost is often based around a single material, such as manure. A single ingredient doesn’t typically compost properly, unless other materials are added. And because it takes time and money to buy the materials and mix them in, commercial-compost makers don’t always add them.

Another major difference between homemade compost and commercial products is the size of the piles. It’s much more difficult to maintain proper moisture and aeration in long commercial windrows, which are often 8 feet tall and 16 feet wide, than in a 4-square-foot backyard pile. As a result, commercial-compost piles that aren’t carefully mixed and maintained can result in poor-quality products.

Dr. Brinton predicts that we’ll see more dry or dehydrated manure products come onto the market. These products often claim to be fully composted, but our tests showed otherwise. “Drying out manure is a shortcut for producers whose main goal is to dispose quickly of excess manure from large animal-confinement facilities,” Dr. Brinton explains. “Such dehydrated manures can still be valuable in the garden, but only if they’re properly labeled so that consumers know to use them at lower rates than mature composts.”

Reprinted with permission from Organic Gardening Magazine

From Garbage to Gold »

by Organic Gardening staff

From the window of his second-floor office deep in the heart of the Intervale, Adam Sherman can see nothing but other people’s garbage. He considers it the best view in town.

Sherman is the organic cooperative’s king of compost. As manager of Intervale Compost, he is in charge of turning 12,000 tons of raw waste a year into 6,000 tons of fine-textured finished compost. In 1999 this “black gold” brought in $450,000 in revenue against $375,000 in expenses. The compost is snapped up in bulk by farmers, landscapers, and golf courses, and in 5-gallon bags, at $2.49 each, by backyard gardeners. It is the nonprofit The Intervale’s biggest moneymaker. Sellouts are common. “We can’t keep up with demand,” Sherman says. “We’re turning people away. They’re heartbroken.”

Sherman and his band of merry composters gleefully violate the sacred rule of backyard composting: no meats, breads, or dairy products. Intervale Compost not only accepts food garbage from restaurants and food services around Burlington; it encourages the practice by charging lower dumping fees than those imposed by local waste-transfer stations. It hauls in tons of litter from animal stables and accepts 1 million gallons of Ben & Jerry’s ice-cream residuals a year. The dairy waste, which has the consistency of a milkshake, is brought in as often as twice daily in giant tanker trucks and sprayed on the windrows. How is this done without creating a big stink and drawing vermin? The secret is in the mix.

Food garbage is carefully blended with vast quantities of bulky dry materials, such as sawdust and leaves. The 400-foot-long windrows soon heat to a steamy 140_F, even in Vermont’s bitter winters, and any odors quickly burn off. The piles are turned frequently with large machines to keep air circulating. “As long as we’re mixing it at the right recipe, it will continue to cook,” Sherman says.

The composting process takes 9 months, and the finished product is balanced between acidity and alkalinity, with a pH level of 7.2. Sherman picks up a handful of the finished, screened compost and lets it crumble through his fingers. “Like a fine wine,” he says fondly, “it only gets better with time.”

Reprinted with permission from Organic Gardening Magazine

Paradise »

by Organic Gardening staff

At the Intervale in Vermont, a community turns a forgotten wasteland into a thriving organic mecca.

Burlington is Vermont’s biggest city, perched prettily on the shores of Lake Champlain and ringed by the Green Mountains. Home to the University of Vermont, it is perhaps best known for its skiers, freethinkers, and trendy coffee shops. But to get to the real heart of this community, you need to travel past the gingerbread Victorian homes and cobblestone streets of downtown. You need to make your way through the city’s depressed north end, past a string of warehouses, and over the railroad tracks.There, on 700 acres of fertile floodplain once home to derelicts, thieves, and junked cars, you will find the Intervale. The moment you step out into the dewy gardens and fields, you know you have arrived at a special place with a special story to tell. It is a story of rejuvenation and hope. It is the story of a community-business leaders, politicians, farmers, and just plain folks-working to reclaim and heal a piece of once-pristine earth that had fallen into ruin.

A Living Experiment

Today the intervale is home to two sprawling community gardens, several small market farms, a flower-growing operation, a small vineyard, a giant-and profitable-composting facility, a children’s garden, and the restored homestead of colonial pioneer Ethan Allen. The Cook’s Garden seed catalog has its demonstration trials here, and Gardener’s Supply Company, a direct-mail provider of earth-friendly gardening supplies, houses its retail store and headquarters here. Linking it all together are nature walks and bike trails-and the lazy Winooski River, whose once-a-century floods have kept this rich bottomland free from the developer’s bulldozer. All crops are grown to Northeast Organic Farming Association standards.

On a crisp summer day the place is alive with activity. Art students from a local community college dab at their canvases in the overflowing perennial beds of the Stray Cat Farm cut-flower gardens. Down the dirt road at the Intervale Community Farm, members of the cooperative arrive to pick up their weekly boxes of vegetables and flowers. Children dart among the cosmos and sunflowers. A local baker sells fresh bread. A poultry farmer hawks free-range chickens. Frequent volunteer Bonnie Acker and her daughter, Dia, 10, work on building a shed. “This place gives you goose bumps,” Acker says. “Dia loves it here. She’s grown up living in the city but also living on a farm.”

At The Cook’s Garden demonstration trials nearby, founder Shepherd Ogden fusses over beautiful beds of mixed mesclun greens and chard. When asked how he keeps his plants so robust, he replies, “It’s basically just compost and attention to the details. That’s all it takes.” As if in testament to those details, Ogden and his 16-year-old daughter, Molly, are later spotted in a distant field, hand-weeding open-pollinated tomato and pepper plants. When the fruits mature, he will handpick only the best specimens and sell their seeds through his catalog. “If I want certified-organic seed, especially of unusual varieties, this is the way I have to do it,” he says.In the vineyard behind Ogden’s beds, wine maker William O’Connor uncorks a bottle labeled “Intervale Red 1997″ and shares a glass with a visitor. It is fruity, not too sweet, and surprisingly good.

At the end of the workday, local residents begin showing up to tend their personal patches. Bicyclists breeze past. A friendly neighborhood dog lolls down a pathway. A tanker truck filled with ice-cream residue from a Ben & Jerry’s manufacturing plant 20 minutes down the road in Saint Albans rumbles up and sprays what appears to be the world’s biggest chocolate milkshake onto the long piles of cooking compost. It’s the regular addition of Ben & Jerry’s ice cream (1 million gallons a year) that gives the Intervale compost its unique microbial life, adherents say.

A Story of Regeneration

The intervale wasn’t always so vibrant or pristine. Talk to any longtime city resident and you’ll hear the same story: For decades this was a place you wouldn’t feel safe going into after dark. As Ogden puts it, “This was a serious hobo jungle down here.” For years it served as the city garbage dump. After the dump was closed in the 1920s, locals still felt free to illegally drop off trash they needed to get rid of. Hundreds of junked cars rusted in weedy fields. The little bit of farming still taking place here was being done chemically, and the sandy soil allowed pesticides and fertilizers to leach directly into the water table.

“This was the unsavory part of town,” says Will Raap, founder of Gardener’s Supply Company and a guiding force behind the Intervale. “It was a barely-holding-on type of place.”

Shortly after founding Gardener’s Supply in an old carpet factory outside Burlington in 1983, Raap set out to change that. He looked at the forsaken bottomland area and saw more than trash piles and bankrupt soil. He saw a natural resource with a proud agrarian tradition dating back 5,000 years. The Abenaki tribe fished and grew maize there. Colonial settlers, Ethan Allen among them, raised vegetables, dairy herds, and hemp on the river’s rich silt deposits. What once was could be again, Raap figured, but it would require a community effort.

An urban planner by training, Raap was in the vanguard of the organic movement in the 1960s and ’70s and had long dreamed of finding a place where he could demonstrate locally the global principles of responsible, sustainable agriculture. This weedy, forgotten bottomland, it dawned on him, might just be that place. “You can think about it; you can write about it. But until you can show it, people can’t internalize it,” he says. He leased land in the Intervale from a local farmer and moved Gardener’s Supply there in 1985.

Others, including city leaders, gradually signed on to Raap’s dream, and in 1989, Intervale Community Farm, Vermont’s first Community Supported Agriculture farm, opened at the Intervale. The next year, the nonprofit The Intervale was formed. The goals were simple: recycle the city’s waste into compost; use that compost to heal the damaged soil; give fledgling organic farmers affordable leases for land and farm equipment to help them get started; and return fresh, healthful produce to the community.

Andy Jones, 31, manager of Intervale Community Farm, which provides organic produce and flowers to 400 subscription-paying households, is one of the young farmers who has benefited from the foundation’s incubator program. Without the affordable land leases and equipment rental, his thriving 21-acre farm might not have been possible. “That program has made a big difference for a lot of people,” he says.

The Intervale’s 700 acres were assembled through a patchwork of leases, purchases, and informal arrangements with a variety of private and public owners. Much of it is managed under the stewardship of the nonprofit foundation, with Raap as its chairman.

One of the first steps was to make a deal with city residents: Bring us your leaves in fall and we’ll give you coupons redeemable for free compost in spring. The arrangement became immensely popular. The foundation also arranged to haul food garbage from local restaurants and the city’s hospital to be composted. These businesses could then buy food grown by the foundation’s farmers, who used that compost to feed their crops.

The Intervale’s mission is to recycle 10 percent of Burlington’s waste and to supply 10 percent of its fresh foods. Today it’s well on its way to meeting those goals. It now reduces the amount of non recyclable solid waste the county receives by about 10 percent and provides 4 percent of its fresh foods.

At the entrance of the Intervale, Burlington’s wood-fired power plant converts the region’s abundant tree trimmings, lumber scraps, and other biomass into electricity. On the drawing board are plans to recycle waste steam from the power plant into free heat for 50,000 square feet of Intervale greenhouses. Those greenhouses will allow the year-round food production that will bring the Intervale closer to its goal of becoming the city’s breadbasket.

Another project, the Living Machine, is under way to perfect a system of raising tilapia (a gourmet fish) for market. Spent beer hops from a local micro brewery are used to feed worms, which in turn feed the fish. The nutrient-rich fish waste is used as plant food.

Burlington Mayor Peter Clavelle says the Intervale is a rediscovered treasure. “As our community has returned this land to its original fertility…we’re creating an invaluable legacy for our children and their children.”

“We changed the whole attitude of the city from looking at this as a dumping ground to looking at it as an agricultural and recreational resource,” says Raap, who describes himself as a reluctant capitalist.

The Intervale, he says, proves that a sustainable, organic circle of waste recycling and food production is not an idle dream. “It demonstrates on a citywide basis that there is a continuum, just like in your garden, between waste, compost, and food,” he says. “It demonstrates that we don’t need to be at the mercy of industrial agriculture. We are creating models here that we think are exportable.”

Reprinted with permission from Organic Gardening Magazine