What To Put In Garden Compost

Your Step-by-Step Guide to Making Compost That Will Enrich Your Garden

It's the gift that keeps on giving. You can turn your food scraps and yard waste into "black gold" that will feed your plants and improve your soil.

Each product we feature has been independently selected and reviewed by our editorial team. If you make a purchase using the links included, we may earn commission.

Some common misconceptions of home composting are that it's too complicated, it'll smell funny, and it's messy. These may be true if you compost the wrong way, but composting the right way is actually quite simple. Just layer organic materials, add a dash of soil and a splash of water, and wait for your concoction to turn into humus (the best soil booster around!). You can then improve your flower garden with compost, top dress your lawn, feed your growing veggies, and more. Once you get your compost pile started, you'll find that it's an easy way to repurpose kitchen scraps and other organic materials into something that can help your plants thrive.

compost soil on shovel

Types of Composting

Before you start piling on, recognize that there are two types of composting: Cold and hot. Cold composting is as simple as collecting yard waste or taking out the organic materials in your trash (such as fruit and vegetable peels, coffee grounds and filters, and eggshells) and then corralling them in a pile or bin. Over the course of a year or so, the material will decompose.

Hot composting requires you to take a more active role, but the return is that it's a faster process; you'll get compost in one to three months during warm weather. Four ingredients are required for fast-cooking hot compost: Nitrogen, carbon, air, and water. Together, these items feed microorganisms, which speed up the process of decay. In spring or fall when garden waste is plentiful, you can mix one big batch of compost and then start a second one while the first "cooks."

Vermicompost is made with the help of worms. When these worms eat your food scraps, they release castings, which are rich in nitrogen. You can't use just any old worms for this, however: You need redworms (also called "red wigglers"). Worms for composting can be purchased inexpensively online or at a garden supplier.

compost bucket

Credit: William N. Hopkins

What to Compost

Composting is a great way to use the things in your refrigerator that are a little past their prime, which helps reduce food waste. You can also compost certain kinds of yard waste rather than send them to the dump. Collect these materials to start off your compost pile right:

Fruit scraps
Vegetable scraps
Coffee grounds
Eggshells (though they can take a while to break down)
Grass and plant clippings
Dry leaves
Finely chopped wood and bark chips
Shredded newspaper
Straw
Sawdust from untreated wood

Keeping a container in your kitchen, like this white ceramic compost bucket ($25, World Market), is an easy way to accumulate composting materials as you prep meals. If you don't want to buy one, you can make your own indoor or outdoor compost bin. For kitchen scraps that could start spoiling quickly, another option is to store them in the freezer until you are ready to add them to your larger outdoor pile.

How to Make Hot Compost

1 Step 1: Combine Green and Brown Materials

To make your own hot-compost heap, wait until you have enough materials to make a pile at least 3 feet deep. You are going to want to combine your wet, green items with your dry, brown items. "Brown" materials include dried plant materials; fallen leaves; shredded tree branches, cardboard, or newspaper; hay or straw; and wood shavings, which add carbon. "Green" materials include kitchen scraps and coffee grounds, animal manures (not from dogs or cats), and fresh plant and grass trimmings, which add nitrogen. For best results, start building your compost pile by mixing three parts brown with one part green materials. If your compost pile looks too wet and smells, add more brown items or aerate more often. If you see it looks extremely brown and dry, add green items and water to make it slightly moist.

2 Step 2: Water Your Pile

Sprinkle water over the pile regularly so it has the consistency of a damp sponge. Don't add too much water, otherwise, the microorganisms in your pile will become waterlogged and drown. If this happens, your pile will rot instead of compost. Monitor the temperature of your pile with a compost thermometer ($19, The Home Depot) to be sure the materials are properly decomposing. Or, simply reach into the middle of the pile with your hand. Your compost pile should feel warm.

3 Step 3: Stir Up Your Pile

During the growing season, you should provide the pile with oxygen by turning it once a week with a garden fork ($37, The Home Depot). The best time to turn the compost is when the center of the pile feels warm or when a thermometer reads between 130 and 150°F. Stirring up the pile will help it cook faster and prevents material from becoming matted down and developing an odor. At this point, the layers have served their purpose of creating equal amounts of green and brown materials throughout the pile, so stir thoroughly.

Test Garden Tip: In addition to aerating regularly, chop and shred raw ingredients into smaller sizes to speed up the composting process.

4 Step 4: Feed Your Garden

When the compost no longer gives off heat and becomes dry, brown, and crumbly, it's fully cooked and ready to feed to the garden. Add about 4 to 6 inches of compost to your flower beds and into your pots at the beginning of each planting season.

Some gardeners make what's known as compost tea with finished compost. This involves allowing fully formed compost to "steep" in water for several days, then straining it to use as a homemade liquid fertilizer.

Every gardener is different, so it's up to you to decide which composting method best fits your lifestyle. Fortunately, no matter which route you choose, compost is incredibly easy to make and environmentally friendly. Plus, it's a treat for your garden. With just a few kitchen scraps and some patience, you'll have the happiest garden possible.