Backyard Composting
How-to advice to get started!
College of
Agriculture and
Natural Resources
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What is compost?
Why start composting?
Pick a place. Build your pile.
Active (hot) vs. passive (cool).
How do I use it?
Resources to learn more.
Compost Through History
• Reference to use of manure in agriculture
on clay tablets, 23rd Century BC.
• Romans and Greeks used compost.
• William Shakespeare’s Hamlet advised:
“Do not spread the compost on the
weeds, to make them ranker.”
Famous Composters
• Many of America’s founding fathers were
farmers. All used compost.
• George Washington Carver said,
“…a compost pile is essential and can be
had with little labor and practically
no cash outlay.”
Compost importance grows
• In 1905, British agronomist learned
best compost consisted of three times as
much plant matter as manure.
• Rapid composting techniques developed
in 1950-1960s.
What is Compost?
• Organic material from decomposition of
carbon (dried leaves), nitrogen (food scraps).
• Happens naturally – certain techniques
accelerate the process.
• Dark, crumbly, soil-like.
Why is it Important?
• Reduces waste stream.
Yard and food scraps = 30% of landfill
• Improves soil structure.
• Retains moisture, slows run-off from rain.
• Reduces need for
fertilizer.
Starting a Compost Pile
• Select a location – away
from the house.
• Make your own, buy a tub,
use pallets for 3-bin style.
Starting your Compost Pile
- Ideal size is 3 ft. x 3 ft. x 3 ft. (27 cubic ft.)
Easier to turn, maintain aerobic action
- No larger than 5 x 5 x 5
Can be anaerobic if too large
What goes in your Compost
Carbon: dried leaves, straw
Nitrogen: food scraps, plants
Water: moisture
Oxygen
Carbon
Nitrogen
BROWNS
GREENS
Dried leaves
Straw
Shredded paper
Drier lint
Newspaper
Pine needles
Sawdust
Peanut shells
Kitchen scraps
Coffee grounds & filter
Tea bags
Fresh garden trimmings
Pet hair
Manure (from herbivores:
poultry, cattle, goat)
A Few Things to Avoid
- Meat, bones
- Dairy products
- Fats and oils
- Pet feces (dog, cat, other carnivores)
- Wood ashes
These can attract critters you don’t want,
may create odd odors, or contain harmful
bacteria/parasites.
Turn it to add Oxygen
Keep the worms, bugs, microbes happy and
eating your browns and greens. Use a pitch fork
to turn the pile.
Bugs, worms, flies, oh my!
Bugs, worms, flies, oh my!
• Soil invertebrates chew, decrease size of
materials for microorganisms.
• Mesophiles: microbes, decomposers that live
and reproduce between 40 and 110 F.
• Thermophiles: microbes, decomposers that
live and reproduce between 110 and 170F.
Active (hot) vs. Passive (cool)
• Hot composting
Materials added all at once. Temperatures 110-140 +.
Finished in three to four months.
• Cool composting
– Continuous pile. Add material as it’s available.
– Trench. Kitchen scraps placed 12” deep and
covered immediately. Typically near garden.
– Sheet. Layers of newsprint, yard waste, dried leaves.
Ready in six to eight months (next season).
Troubleshooting
Materials not decomposing:
Add water, turn pile to add oxygen, add more greens
Ammonia odor:
Add browns such as leaves, straw
Rotten odor:
Turn pile, add coarse dry materials.
Bury food scraps
OK, when is it done?
When:
• material is even color, texture
and has an earthy smell.
• temp of pile is at outdoor temp.
• a small amount in sealed plastic bag
creates no condensation inside bag.
How to use your Compost
• Mulch for garden, fruit trees
• Top dressing on flowering plants
• Soil improvement, helps change structure
– Enhances moisture retention
– Improves drainage in clay soil
– Attracts earthworms which
aerate soil
Compost Demonstration Sites
Master Gardeners offer how-to advice at five locations in Howard
County from April to November. Free bin to County residents.
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Schooley Mill Park
Centennial Park
Alpha Ridge Landfill
Miller Branch library
Robinson Nature Center
Top Reasons to Compost
 Reduces need for chemical fertilizers, mulch.
 Improves the structure of your soil.
 Reduces yard waste going to landfill.
 Slows storm water run-off, help protect Bay.
 Decreases water use in your landscape.
 It's easy. Good exercise!
Resources to Learn More
• Home and Garden Information Center (HGIC)
extension.umd.edu/hgic/resources
• HC Bureau of Environmental Services
howardcountymd.gov/composting.htm
• Howard County Master Gardeners
The University of Maryland Extension programs are open to any person and will not
discriminate against anyone because of race, age, sex, color, sexual orientation, physical or
mental disability, religion, ancestry, national origin, marital status, genetic information,
political affiliation, and gender identity or expression.