 Many gardeners have a compost pile or bin at home that serves to break
down their yard waste and plant-based kitchen waste. For this type of
compost to work, you need carbon (brown, dry material such as raked
leaves), nitrogen (wet, green material like veggie scraps), water and
oxygen. The right balance of these elements is necessary to ensure each
component serves its purpose. The ideal blend is about one part nitrogen
to four parts carbon, and the pile should maintain the consistency of a
damp sponge. A good example of this method is an old hardwood forest
floor. Scrape aside the layers of accumulated leaves and you’ll find
soil that’s rich, moist and dark in color from the years of composted
leaves and other organic matter. Acceptable materials for your home
compost pile are plant-based kitchen scraps (no meat or dairy), egg
shells, unbleached paper products, coffee grounds and tea leaves, grass
clippings and other yard waste.
An alternative to the pile method is composting using insects such as
black soldier fly larvae, night crawlers or grubs. In warm and humid
climates, black soldier fly larvae exist naturally in compost piles. The
flies themselves live most of their lives out of sight in the trees,
but the larvae can fully compost food scraps in 24 to 36 hours. Red
wigglers (a type of earthworm) can be kept in a bin designed for a
method of composting called vermicomposting. It’s difficult to get just
right, but can be very effective. The result is a rich soil additive
commonly referred to as worm castings, and a tea from the castings can
also be poured from the bottom of the bin if there is adequate moisture.
 Bokashi
composting is another alternate form, and uses materials such as bran
that have been inoculated with composting organisms called “effective
microbes,” which ferment and accelerate the breakdown of the organic
matter. The anaerobic (without oxygen) nature of this type of composting
reduces the rotting odors typical of aerobic composting. And because
the fermentation process happens without oxygen, meat and dairy products
can be included in a Bokashi bin.
Kitchen scraps go into a
bucket along with the inoculated material, and as they break down, about
a cup of nutrient tea can be drained off every few days. When the bin
is full and a thin layer of mold is present (indicating the fermentation
is complete), it’s time to bury the contents. Dig a shallow trench in a
fallow area and empty the bucket into the trench. Cover, and in two to
four weeks, the organic matter will have fully broken down into rich
soil. Both the nutrient tea and the pulp are immediately beneficial to
all plants, including lawns. The tea adds microbial life to the soil and
helps plants retain moisture.
The Bokashi method eliminates the
need for adding yard waste, allows for composting a wider range of food
scraps and, best of all, in the summer heat can be done primarily
indoors. Patrick Van Haren, the founder and owner of Microbial Earth who
sells Bokashi systems locally, has his bin on an enclosed back porch.
According to Van Haren, the resulting compost is like “sauerkraut for
the soil.” He likes to puree his scraps when possible in a Blendtec
blender along with a little water to speed the process along and get
more compost tea out of the bin.
The Bokashi method is ideal if
your home doesn’t produce enough kitchen or yard waste to achieve the
right balance for pile composting, but it doesn’t produce a large volume
of new soil. Instead, it produces a nutrient-dense soil additive that
builds the soil that is already there. It also saves the water needed to
keep a compost pile moist during the dry, hot months and it reserves
leaves and grass clippings so they can be used as mulch or simply left
on the lawn where they will enrich the soil and help the lawn hold
moisture. This method is a much quicker path from kitchen to compost,
and preserves the greatest amount of nutrients that can be returned to
your own garden. According to Van Haren, the liquid tea provides for 17
times more frequent cycling of nutrients (an exchange of organic and
inorganic matter back into the production of living matter) than
traditional composting, thereby building nutrient density in the foods
grown in treated soil. And because oils, greases and animal tissues can
be included, those things are removed from the sewage system, saving
taxpayers money.
Whichever method is right for your home,
consider starting a composting system this summer. You’ll have a great
head start on the fall growing season and you’ll be contributing to the
health and sustainability of your community and planet.
See Our Selection of Composters available online
RESOURCES
The Complete Compost Gardening Guide, by Barbara Pleasant and Deborah L. Martin. Lewis (Storey Publishing, LLC, 2008)
Microbial Earth, Patrick Van Haren, the founder and owner
Laura McKissack is a blogger and foodie who's been gardening organically
for six years. She volunteers for Sustainable Food Center, the Texas
Parks and Wildlife Department and Central Market Cooking School. She is
also an assistant at the Natural Gardener and works at Botticell's
South Congress part-time to get her foodie fix. Visit her blog at junebugsoup.blogspot.com for recipes, photos and reporting on food events around town. She has written multiple articles for Edible Austin.
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