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| Garbage to gold: Gardeners achieve an age-old dream (Fall 2007) |
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By Bob Tracinski, master gardener
It was a dream of medieval alchemists:
Turn worthless materials into gold. They
called it transmutation. Gardeners call it
composting. They turn worthless leaves
and kitchen refuse into nutrient-rich earth
that can cost a fortune to buy. The science of
composting starts with these basic principles.
4 by 4.
Make the pile at least 4 feet high
and 4 feet in diameter. It needs enough mass to
create an internal temperature of 160 degrees.
Build in tiers.
Dry stuff, then wet stuff,
capped by soil—in 5- to 10-inch layers. Dry
stuff includes tree leaves. Wet stuff includes
fresh grass clippings, weeds, and kitchen
scraps. The soil provides the good microbes
that chew on the other stuff.
Add nitrogen.
Microbes need it to work
faster. Green grass is a good source. Regular
10-10-10 garden fertilizer works well; sprinkle
a couple of handfuls over every layer.
Aerate.
Microbes require air to work faster,
so turn the compost once or twice a month. Some anaerobic microbes work
without air, but they work slowly and stink.
Irrigate.
Keep the compost moist but not
soggy. Take a handful and squeeze it. If no
water dribbles out, it's too dry. If a lot of water
pours out, it's too wet.
Think small.
Little particles decompose
faster. However, you don’t have to shred
everything. If whole leaves are composted,
then be sure to keep them wet and add lots of
high-nitrogen fertilizer. Shredded material in
warm weather takes about two to four months
to break down. Unchopped material left alone
can take a year or more. A compost pile started
in fall may not be ready by spring because of
cold temperatures over winter.
Avoid bad things.
Meat, bones, and grease
attract rodents. Pet manure transmits disease.
Citrus rinds, corn cobs, and nut shells take
forever to decompose. Charcoal never does
and coal ashes can be toxic. Plant diseases
and weed seeds will be destroyed by the high
heat at the center of the pile, if you turn the
compost often enough to fold the cooler outside
portion into the pile middle.
Contain the pile.
But keep it simple. A circle
of chicken wire can be used. Staple boards to
each end and attach fasteners to the boards.
When the compost is ready to turn, undo the
fasteners, remove the circle of wire, set it up
next to the pile, and shovel the compost back
in. Some gardeners build three-compartment
bins so they can constantly add new material
for continual compost production. Turn the
compost in the second compartment, add new
material to the first, let the third hold compost
ready for use. A bin like that should be made
from treated wood or metal to resist rot.
When the compost has been reduced to
half its original bulk and has the earthy
aroma of pay dirt, then you have a gardener’s
treasure—the nutrient riches that can
transmute a simple garden into a beautiful
display of giant vegetables or flowers.
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