SoilSaver Compost Bin

Green Mountain Compost now sells SoilSaver backyard compost bins. These home composters aren’t going to produce mountains of compost, but they’re a handy way to get rid of food scraps, yard clippings and leaves while still yielding some rich, dark compost for your garden. Click here for more information on purchasing a SoilSaver compost bin.

And don’t forget–we’ve got plenty of FREE 4-gallon and counter-top compost buckets, great for collecting food scraps for either drop-off or home composting.  Come on down, grab a bucket, and help keep compostable material out of the landfill.  (And save money too!)

Casella dumping food scraps

Due to the big move, it had been several months since we’d been able to make new compost.  When those first few loads of horse manure and food scraps rolled in, our head honcho compost-maker Norman Gordon was all smiles.  And there’s more than that to smile about here at Green Mountain Compost.  Our new state of the art facility allows us to make compost faster and more efficiently than ever, which means a smaller ecological footprint and even better products for our customers.

Brand new facility

Our new facility features a large building with rows of covered bays on an expansive concrete pad. Liquid runoff from the process is captured and reused in the process.  Most of the bays have slotted floors that allow air to be blown up into the piles of compost.  This “static aerated” system allows for oxygen to penetrate the piles more effectively than with our former “turned windrow” method.   The result is a faster process, drier compost, and much less diesel fuel used.  Yes!

 After aeration, the piles are incorporated into larger piles for curing through maturity.  Because this new process produces drier finished material than at our old facility, we are able to screen using a new 3/8-inch screen, which means a finer texture than with the previous 1/2-inch screen.

Aerated compost-making bay

With covered bays, a concrete pad, an aerated system and finer screening, this new facility will allow us to make compost more efficiently and more effectively.  Our winning compost recipe hasn’t changed, but this new technology means higher quality finished products.  We think our customers will smile on that.

New state of the art facility

We are open and ready for business at our shiny new state-of-the-art facility on Redmond Road in Williston.

We’re sad to say goodbye to all our great Intervale neighbors, but we’re excited to be able to continue making great soil products for our loyal customers, and to expand our good soils/good food community even farther.

So come on out and see our new digs, where you can drop off food scraps and yard debris and purchase any of our quality soil products in bulk. To buy our products in 20-quart bags, Terra Fuela sunflower growing kits, or to find a retailer closer to home who sells Green Mountain Compost or Premium Top Soil by the yard, please consult our Where To Buy page.

We’re still putting the final touches on all the little details, but keep your eyes peeled for more news and happenings at the new location!

Summer hours: Monday – Saturday 8 a.m. – 4 p.m.

DROP-OFF SCHEDULE: The new facility is now accepting material for composting Monday – Saturday 8 a.m. – 4 p.m. Please visit our What is Compostable page for more information.

Certain varieties do better than others when saved for multiple years. Seeds in the allium or onion family don’t store as well as others, so if you have onion, chive, scallion, leek, or shallot seed kicking around for more than a couple of years, it’s a good bet that you won’t have much success getting them to germinate in large numbers.

If you want to be sure that your seeds will germinate before going through the trouble of planting them, check out these germination test instructions from the folks at High Mowing Organic Seed.

Once you’ve determined that they’re good to go, we recommend getting your seedlings started in a high quality germinating blend such as our Premium Seed Starter Mix.

Looking for a source for seeds? We’re giving away a packet of free seeds with every yard of soil or mulch this season. Check out our free seeds page for details.

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

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

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

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