pH is the chemical measure of acidity(sourness) or alkalinity(sweetness).
On the pH scale of 0 to 14, 0 is highly acidic, and 14 is highly alkaline.
Garden soil has a pH, and varies by type of soil and what is in it. Compost,
soon to be garden soil, also has a pH. And, it can vary significantly, depending
upon what you put into your composter.
The ideal pH for most plants, is at or near the midpoint: 6.5 - 7.0 If compost
or soil is too acidic, or too alkaline, plants can not grow.
Most of us put a wide variety of materials into our composter. Most (but
not all) plants and weeds have a pH near or slightly below 7. Other compostable
items can vary widely. So, it's important for you to have some knowledge
of the pH value of items your place in your composter, and ultimately into
your garden soil.
After your compost has decomposed, and before you mix it onto your garden,
we recommend a quick home soil test for ph levels. See
Electronic Soil Testers
For more information, see: Soil pH
All about Composting
Find Ideal pH levels for a wide range of flowers,
vegetables and herbs.