Frequently Asked Questions (FAQs) About Composting
What should I or shouldnt I add to my compost pile?
Do add: yard trimmings, garden debris, vegetable and
fruit scraps, coffee grounds and filters, and horse, cow chicken,
and rabbit manure.
Do not add: meats, fish oily foods (these are likely
to attract unwanted pests), milk products, and pet manures (except
for manure from pets that are herbivores such as rabbits, sheep
and chickens; their manure is a great source of nitrogen). Diseased
or insect infested plants and weeds that have gone to seed also
should not be added.
Materials that you can or cant add to your compost pile
depend partly on the health regulations in your area:
Ask your township or borough if they have regulations on
composting food scraps. They may require a covered bin or may
not allow food scraps composting outdoors.
How do I keep pests out of my compost?
To help keep pests out of an open pile, turn food scraps
into the pile as you add them, covering them with yard trimmings.
Make or buy a bin that is pest resistant; one that has a
lid & has air holes small enough to keep out small pests.
If youre having pest problems, try composting food
scraps in alternative ways. You might bury food scraps in your
garden, use a compost cone built specially for food scraps, build
a worm bin for indoor composting of food scraps, buy or make
a barrel composter, or make a trash can compost bin.
Should I put my compost in the sun or shade?
Its best in the shade because the compost is less likely
to dry out. Dry compost does not decay.
How long does it take to compost?
Depending on how carefully you manage your pile for the correct
conditions, composting takes from 1 month to 2 years.
A pile turned every week or so and carefully managed for
all the right conditions may compost in a month or two.
A pile not turned or managed will take about six months to
two years to fully compost.
It is not essential to compost quickly. Its really
up to you if you want compost for your garden as soon as possible
or if youd rather wait for nature to run its course. Just
be sure to compost responsibly and turn your pile if it starts
to give off foul odors.
Do I need to shred or grind organic materials to compost them?
Shredding or grinding organic materials helps speed composting
by increasing the surface area of the compostables, making them
accessible to decomposers. But shredding is not essential, except
when adding woody materials such as sticks that will take years
to decompose unless they are shredded.
One word of caution: shredded and ground materials tend to
have less air flowing through them, so they should be turned
more often if you are an active composter.
Should I add inoculents and activators/accelerators?
Inoculents and activators are not recommended. Inoculents
are microscopic decomposers, and they are naturally found in
the source materials you add to your pile, such as leaves and
grass. They are abundant in soil, finished compost, and manures.
Just 1 teaspoon of fertile soil with compost regularly added
to it has 100 million bacteria and 400-800 feet of fungal threads,
according to a soil ecologist at Oregon State University.
Accelerators are generally a quick fix of nitrogen that wont
last long and are a potential source of water pollution as they
are easily washed out of your pile into surface and ground water.
If you need to add high nitrogen "greens" to your pile,
organic sources like grass clippings, manure, food scraps or
even bone meal give a slow release of nitrogen and are better
Should I add lime to my pile?
Do not add lime to a pile because it may cause nitrogen
to be released from the pile as ammonia gas. This gas smells
bad and leaves your compost with less nitrogen, an important
plant nutrient for you garden.
You dont need to worry about the pH of a compost pile.
pH, being a measurement of alkalinity or acidity, will generally
adjust itself and when compost is mature, the pH is usually around
If you need to adjust the pH of compost, do this after
it has completed its composting. First test the pH of your finished
compost and adjust it as needed.
How do I know when the materials are done composting? And
what can I use the compost for?
How you plan to use your compost determines how mature or "done"
it should be:
Compost used for mulch can be partly decomposed. Its
ok if you still recognize some of the source materials you put
into the pile. Use the compost as a surface mulch on garden soils
or flowerbeds and around trees and shrubs.
Partly decomposed non-woody compost can be added as a conditioner
to your garden soils in the fall, giving the materials time to
finish decaying before you plant in the spring.
Mature compost can be used for making compost tea (not
for human consumption). To do this, put mature compost in cheesecloth
or an old rag and soak it in water until the water is the color
of weak tea. The tea can be used to add nutrients to house and
For incorporating compost into your soil during the growing
season, for planting trees, for use as a lawn top dressing, or
for establishing a new lawn, you want to make sure that your
compost is "mature," meaning:
It is reduced to about 1/3 of its original volume
It is dark, crumbly, earthy smelling (not smelling like ammonia
or rotten eggs), and the original materials are not recognizable
The temperature of a pile is within 10 degrees F of the outdoor
temperature (not hot and steamy)
For these more sensitive uses, it is best to first test
out the compost in a small area to be sure it is mature enough
to not damage the plants or prevent germination.
Prepared by Penn State Cooperative Extension of Montgomery
County, Recycling Education Program