Chelan County Master Gardener Bonnie Orr scoops out finished compost from her “hot pile” that only takes a few months to break down vegetation.

It is the middle of summer. What are you doing with your lawn clippings? What happens to your left-over vegetable scraps from fixing dinner?

It might be the time to set up a compost pile.

The most effective compost piles have to be in contact with the soil so the micro-organisms and red wiggler worms can activate the composting process. There is no need to buy worms or starter organisms.

The size of the pile is critical. A cubic yard is about right; 3x3x3 feet is large enough to create the heat to break down organic materials and small enough that all materials can be incorporated with minimum turning.

In North Central Washington, the compost pile has to be watered during the summer. Its texture should be about as damp as a wrung-out sponge. If it is too wet, you will drown your worms and other beneficial insects. If it is too dry, the microorganisms cannot utilize the organic material.

In the fall, you can save leaves for next year’s compost pile. For this year, you can purchase straw or get straw from a friend who has farm animals. The dry material, usually brown, allows air to circulate. Composting is an aerobic process, and that is why air has to be available to all the organisms working to break down your garden and kitchen waste.

Keep a container near the sink and be sure to add all the vegetable and fruit scraps and the extra tea or coffee and the grounds and the filters.

No animal waste, no meat scraps, no fats — because these materials break down by rotting, which is an anaerobic process and can also attract vermin to your pile. Don’t add rose stems or other thorny things since the thorns will not break down for years.

Weeds that have not set seed will break down in the compost pile. If you waited a week too long, and the weeds have flowers and seeds, put that material in a black plastic bag, seal it tightly and put it in a very hot place such as your asphalt driveway. After about 10 days, open the bag carefully — it will be smelly — and pour the dead gunk into the center of your working compost pile.

By March, your compost will be black and crumbly and have no smell or bugs and no recognizable plant parts. It is ready to incorporate into the soil.

Add no more than 10 percent by volume of compost to your soil. Compost increases the water hold-capacity of the soil. It also provides “loft” — air spaces for roots to move more easily through the soil. You can overdo a good thing by adding too much compost.

The WSU Master Gardeners can provide additional information about composting. Call 667-6540 to find out more.

A WSU Master Gardeners of Chelan County column appears weekly in The Wenatchee World. Bonnie Orr is one of four columnists featured.