In the com­post pile, green and brown make black gold

The Hamilton Spectator - - STYLE - BAR­BARA DAMROSCH

Com­post ma­te­ri­als are plen­ti­ful in sum­mer. The weeds we pull and the grass we mow could eas­ily fill the pile to over­flow­ing, and, af­ter it set­tles a bit, fill it again.

But with com­post-mak­ing, va­ri­ety is more im­por­tant than vol­ume.

Most com­post in­gre­di­ents fall into two cat­e­gories: green and brown. The moist, green ones are ni­troge­nous (high in ni­tro­gen), and the dry, brown ones are car­bona­ceous (high in car­bon). Put them to­gether, and they’ll stir up heat, with car­bon as the fuel and ni­tro­gen the flame.

Both must be in bal­ance, though. An all-green pile breaks down too fast, as the ni­tro­gen volatilizes. It smells foul and burns crops with its caus­tic heat. An all-brown heap, by con­trast, would ul­ti­mately break down, but very slowly. So the trick is to add some green ma­te­ri­als, then a layer of brown ones, then green again — as if you were mak­ing a highrise sand­wich.

The com­post­ing process in­volves chem­i­cal re­ac­tions, but it’s a phys­i­cal process, too. Brown in­gre­di­ents such as twigs, straw, crisp oak leaves, corn­stalks and dead bean vines hold the par­ti­cles of wet, sloppy green mat­ter apart, with air in be­tween. That’s essen­tial, be­cause the mi­crobes that do the job are aer­o­bic — they need air. And an ac­tive, well-bal­anced pile will not smell.

Al­ways keep di­ver­sity in mind. Dur­ing the green time of year, you might have to look harder for brown in­gre­di­ents. In fall, or in a se­vere drought, there’s lots of crackly brown stuff but not much lush green. Turn­ing the heap from time to time will help keep it ac­tive, as will moist­en­ing it at times when no rain falls. But if the heap is lay­ered in a bal­anced way, you can avoid all that work.

A wide va­ri­ety of ma­te­ri­als pays off in other ways. Each brings its own bi­o­log­i­cal and min­eral pack­age to the ta­ble.

Most ni­troge­nous ma­te­ri­als are lit­er­ally green — weeds you tossed in (avoid­ing those with vi­able seeds), lawn clip­pings, bolted crops such as yel­low-flow­ered broc­coli and tow­ers of let­tuce, the arugula you ripped out be­cause the flea bee­tles got to it, and great zuc­chini tor­pe­does, chopped up for speedy ac­tion.

Food scraps such as ba­nana peels, orange peels, po­tato skins and eggshells will be de­voured by the com­post pile, along with the past-ex­pi­ra­tion-date mat­ter you find in a fridge purge (no oil, meat, fish or dairy prod­ucts). Burned the rice? Pass it along for its rein­car­na­tion as fer­tile soil. From garbage comes black gold.

At times when brown stuff is scarce, a few bales of straw or spoiled hay are great to have on hand. If they’re not avail­able, use hedge prun­ings, saw­dust, wood shav­ings and even pieces of card­board. Pa­per fil­ters can be tossed in with the cof­fee, tea bags with the tea.

Ma­nure, es­pe­cially from horses and cows (never cats and dogs) is a good, bal­anced com­post booster. Crab and lob­ster shells, fish, sea­weed, and other ocean-sourced ma­te­ri­als break down eas­ily and are rich in min­er­als that plants need.

Newspapers in English

Newspapers from Canada

© PressReader. All rights reserved.