Questions About Compost

Q. Lillie in Milwaukee writes: "Why does my compost bucket smell so putrid? I added some soil and now it smells even worse. I don't have a 'real' compost bin, so I use a five-gallon bucket with a tightly fitted lid."

A. This is one of the biggest rookie mistakes in the wonderful world of composting. Kitchen waste alone does not make good compost; it just makes a stinky putrid mess. If you want to recycle your kitchen waste outdoors, you need a professionally-made composter that has a tightly locking lid to exclude vermin like raccoons. And you need the bulk of the raw ingredients to consist of well-shredded 'dry browns' like shredded fall leaves.

And yes, the leaves MUST be shredded.

Or you can recycle your kitchen waste indoors with a worm bin, Specialized worms known as red wrigglers ("the Cadillac of Worms!") will turn that kitchen waste into fabulous fertilizer (known as worm castings'). I recommend using a professionally made bin with a good amount of shredded black and white newsprint (the essential 'bedding') covering the garbage.

And yes, the newsprint MUST be shredded.

Q. Frank in Cherry Hill NJ writes: "I found a bag of Organic Tomato and Vegetable Food in my garage from last year. It has a distinct smell of ammonia. Can I still use it in the garden? If not, can I put it in my compost tumbler with shredded leaves?'

A. 'No' to the garden; 'yes' to the composter, Frank. In the earliest days of composting, farmers were urged to add chemical fertilizers to their compost piles because people were dubious that a finished product that looked like soil could feed plants. Then came the work of Sir Albert Howard, J. I. Rodale and a few other mavericks, and people soon realized that the miracle of composting did not require chemical fertilizers; in fact, they tended to screw it up.

But you have an organic product that has gone somewhat bad (ammonia smell = excess nitrogen), but still possesses other useful natural fertilizers. You can either mix it into a big open pile of shredded fall leaves or use your "tumbler". For best results, a tumbler should be completely filled with raw ingredients (mostly shredded fall leaves) and tumbled until done; a process known as 'the batch method'. Continually adding more material to the mix just slows the process down.

You can even add the old organic fertilizer to an existing batch of half-done material as long as you add more shredded leaves to the mix and continue to tumble or turn for awhile.

Q. Pete in Wilmington Delaware writes: "I just read your book on compost. I found it concise and very helpful. I have a few questions I thought you might be able to answer.
1) Why would someone not use 100% compost as the soil in their garden?"

A.When I started out, my beds were half compost and half native soil that I had raked up to help form the beds; and that worked great. Over the years, I followed my own advice to simply add a fresh two inches of compost to my beds every Spring, and that worked great. But over the course of decades, I found that the beds were getting, for lack of a better word, "heavy". That's when I entered into an intense relationship with perlite that continues to this day.

Perlite, a natural mined volcanic glass that gets 'popped' into little white ball-like structures in giant ovens, greatly improves drainage by providing little spaces throughout your soil that allow for the passage of air and water. Perlite's structure of little cracks and crevices also holds water during wet times and releases that moisture slowly as the soil dries out.

Perlite is a godsend at improving drainage in areas with lots of rain, like my Pennsylvania and Petey's Delaware.

2) "If the ideal C/N ratio for compost is between 25:1 and 30:1, what is the idea ratio of calcium, phosphorus, and potassium?"

A. We're talking apples and oranges here, Petey. The "C/N" (carbon to nitrogen) ratio that makes the best compost and makes it the fastest is indeed 25 to 30 'parts' of dry brown carbonaceous material like shredded fall leaves to every single part of 'wet green' nitrogen-rich material like spent coffee grounds, horse or poultry manure, or kitchen waste.

Calcium, phosphorus and potassium are nutrients that, when seen as lacking, are often applied directly via fertilizers, which are labeled with their unique ratio of nitrogen, phosphorus and potassium (the famed NPK scale). Although chemical companies like to describe things like 10 10 10 as 'balanced', they are not. No plant wants equal amounts of those nutrients. The actual desirable ratio for the vast majority of plants is 1 3 2. Because this IS a ratio, that means 2 6 4 would also be fine. If the plant food in question also provides calcium, it will be listed separately; three to five percent is ideal.

Note: With the exception of calcium, I rely on my compost to provide all the nutrients my plants need.