Guide to Buying Bagged Compost
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Basic Worm Factory® Worm Composting System
Gardeners know compost is good stuff. Made of decomposed organic material, compost improves the soil and helps plants grow. While many gardeners make their own compost, they sometimes need more compost that they can make--or they need compost in a hurry. That's when bagged compost is a great option.
Types of Bagged Compost
Bagged compost may be made of all types of organic matter, including manure, grass clippings, leaves, worm castings and even mushroom compost. Some of the most common include:
Yard waste compost, made from grass clippings, leaves and other plant materials, is excellent for adding organic matter to the soil, improving aeration and increasing water absorption.
Manure compost, usually made from horse, cow or chicken manure, may have other ingredients, like sawdust or straw mixed with it. It often has more nutrients than yard waste compost.
Worm castings compost (vermicompost) is produced from worms feeding on manure and other organic wastes. Often mixed with soil, it can be high in nutrients, so care must be taken when using it.
Knowing Which Bagged Compost to Buy
Many gardeners make their own compost at home. Not only is it a great way to keep wastes out of landfills, it also supplies them with compost they can use in their gardens. Many compost supplies are available for gardeners who want to compost at home. While composting at home offers the advantage of knowing exactly what is in your compost, the disadvantage is that you may not have compost when you need it.
When selecting bagged compost to buy, just follow these steps to determine the best bagged compost for your gardening needs.
- Determine how you want to use your compost. Many gardeners, especially those with clay soil, use compost to improve soil drainage and increase organic matter in the soil. Some also use compost as a mulch. Other gardeners may use compost to add organic matter and nutrients to the soil.
- Read product labels. The better bags of compost list the ingredients in the compost.
- Feel and smell the compost. The best compost is crumbly with a rich, earthy smell. Compost should be not wet and heavy.
Here are some tips for buying bagged compost.
- Pay attention to ingredients in compost, as the ingredients change your soil composition. For instance, manures can add more nutrients to the soil. If seafood shells are in the mix, the soil may become more toxic to nematodes.
- Buy a couple of different types of bagged compost. This can help you see the differences in the mixes. Some gardeners mix different types together.
- Conduct some home tests to determine if it's good or bad compost. Ideally, compost should be free of weed seed and herbicides.
Best Bagged Compost
Brands of bagged compost may be available regionally or nationally. Some of the best bagged compost that are available in several places throughout the United States include:
Tested as an effective soil amendment and a Seal of Testing Assurance recipient, Gardener's Gold is produced with leaves, brush and grass and composted for a minimum of two years. It contains no animal wastes, sludge or industrial wastes. It can be used as a mulch, soil amendment and nutrient supplement. Gardener's Gold improves soil structure and aeration, increases water absorption and reduces nutrient run-off.
Coast of Maine Compost
Coast of Maine offers several bagged compost options, including composted cow manure blended with peat moss, and a blend of lobster shells, compost and peat moss.
Both are designed to improve and revitalize soil.
Made of composted leaves and grass clippings, Leafgro is a good soil conditioner, especially when mixed into the soil before planting shrubs and trees.
Question. Mike: Do you happen to know if it's possible to buy good quality compost in bags? I'd like to use compost in my garden, but only seem to be able to find manure and topsoil in bags at the garden center. I've seen places that will deliver loose compost by the cubic yard, but I don't have a driveway for them to dump it. Love your show!
- ---Peter in Ardmore, PA
Answer. Thanks, Peter! Now if you have access to good quality yard-waste compost in bulk, my first suggestion is to see if it can be delivered to a friend's home nearby or some other mutually agreeable site where several gardeners could share both it and the cost. You'll find lots of info on buying bulk compost in this previous Question of the Week.
Otherwise, the basic answer is yes; there are high quality bagged composts out there. But as with most things gardening, the devil—or angel—is in the details. Here's an updated version of how I addressed this topic in my 2006 book, "Mike McGrath's Book of Compost" (still in print, kids; get your copy today!)
If we're talking about the cheap, wet, heavy, generically bagged stuff without a lot on info on the label sitting out baking in the sun at a big box store, it's not my first choice. (Or second, or third, or…) It shouldn't be anyone's choice, really. The labels and names on cheap bags of "Maybe Compost" are generally somewhere between non-existent, confusing and extremely misleading (as the materials inside the bag often are as well). And this low-rent spread has probably been anaerobic inside that bag for a long time.
If it's all you can find (and it isn't; there's always mail order if you truly live in a horticultural supply desert), two esteemed experts I interviewed for the book, Ohio State University Professor Dr. Dan Herms and University of Maryland Professor Emeritus Dr. Frank Gouin suggest you buy a sample bag, take it home, open it up and give the contents a 'quack' test. (If it looks like good compost, feels like good compost and smells like good compost, it might actually be good compost.)
If it quacks loud enough, go back and get some more, empty the bags out, mix the contents together (ideally with some REAL home made compost or some of the premium stuff we'll soon mention) and let it sit awhile before you use it.
"Square Foot Garden" author Mel Bartholomew once offered a variation on this method during one of our conversations. He suggested you visit a number of different stores, buy one each of their bagged composts, bring them home and evaluate them. Then go back and buy a couple bags each of the best ones and mix them together—again, ideally with some backyard compost or stuff from a premium bag.
BUT you should only do this if you have a high level of internal honesty. If anything tends to be 'good enough' because you already bought it or it's all you could find at the very first store you visited (and your idea of 'good compost' includes slimy things that don't stink really bad), forget about it. You might get lucky, but that's what you'd be. In other words, the odds are against you, and if you feel unable to make the decision with any certainty, cut to the chase and search out some high-quality premium bagged compost instead. You and your garden will be MUCH happier.
Some of the brands I've used and been happy with include "Gardener's Gold" from Garden's Alive; "Coast of Maine" (available in larger independent garden centers from at least New England down to the Washington DC area); and "Leaf Gro", packaged by the state of Maryland's superb yard-waste recycling program—something I'd like to see more states imitate.
There are also two 'specialty' bagged composts I've used: "Chesapeake Blue" (composted crab waste and sawdust) and "Chesapeake Green" (composted poultry manure and bedding). Both are rich in Nitrogen; and Chesapeake Blue has the added advantage of being rich in chitin (pronounced "kite-in"), a substance that occurs naturally in seafood shells, survives the composting process and makes the soil it's applied to toxic to destructive nematodes. In the North, bad nematodes generally only attack a few ornamentals, like boxwoods. But down South, root knot nematodes are a destructive pest of MANY plants. Search for chitin-rich composts, my Southern friends, and you will be happy.
(Note: The beneficial nematodes you purchase to control pests like beetle grubs and fleas in the soil are not harmful to plants. But they are nematodes, and so could also be killed by lots of chitin. Just to be safe, avoid seafood composts if you're applying these helpful creatures to your soil.)
There are probably dozens of other high-quality bagged composts available across the country—these things tend to be regionally produced and packaged. But you should know them when you see them. They will cost a little more, have a lot more info on the label and basically give you a warm and fuzzy feeling all over.
One final note (hey—my producer just keeled over laughing; I wonder why?), peat moss is NOT compost. It is a popular component in seed-starting and potting mixes, and a natural antibiotic that prevents damping-off and some other diseases. But it's too light in weight for many applications, contains little to no actual nutrition, and can radically lower the pH of your soil whether you want it to or not. Now don't get me wrong: I like peat moss. I use peat moss. Peat moss is a friend of mine. "But I know compost; and peat moss is NOT compost."
One OTHER final note (oh—THAT's why she keeled over), Dr. Gouin wants to stress that 'dried' products like Milorganite and dehydrated manure are not compost. Composting is a complex process by which raw ingredients are changed by living organisms and processes. Drying is not the same—not even close. Dried something-or-other can't do all the wonderful things that living compost does.
Helpful Products from Gardens Alive!
Basic Worm Factory® Worm Composting System