Greens provide bodybuilding proteins for the microorganisms crunching through your organic matter. Nitrogen-rich materials are called greens because most of them are greenish in color. The following are good sources of nitrogen for your compost pile:
Kitchen scraps: Leftovers from the kitchen are excellent additions to the compost pile. You do the environment a big favor too by adding the following scraps to your compost:
Coffee grounds and used filters
Condiments and sauces
Corncobs
Cut flowers
Eggshells
Fruit pits
Fruit rinds and cores
Nut shells
Shells from shellfish
Stale or moldy bread and grain products
Tea and tea bags
Vegetables (raw or cooked)
Fruit pits, eggshells, nut shells, and shellfish shells are slow to decompose. Crush or grind them before adding them to your compost pile to speed the process.
Grass clippings: Grass clippings turn slimy and smelly if left in big piles or layered too thickly, so mix them up with brown materials or spread them out to dry for a few hours before mixing them into your heap.
Leafy plant trimmings, spent flowers, herbs, and vegetables: When your garden plants have finished producing for the season, pull them out, chop or tear them into smaller pieces, and toss them into the compost pile to recycle their nitrogen content. The same goes for leafy trimmings from landscape shrubs and trees.
Weeds — foliage only: A healthy crop of weeds, although annoying, is a fine source of nitrogen. Return those nutrients to your garden where they belong by composting your weeds.
Livestock manure: Chicken, cow, duck, geese, goat, horse, llama, rabbit, sheep, and turkey manures are safe to add to compost. Manure contains small amounts of nitrogen, phosphorus, and potassium that all plants require, as well as boron, iron, and zinc.
If you're using manure directly on your garden, it must be at least six months old to be safe. Fresh manure, in addition to being smelly, contains concentrated nitrogen that may "burn" plant roots and tender seedlings or prevent seed germination. If you happen to obtain super-fresh wet manure, use it in the following ways:
Let it dry out before adding it to your compost, and blend it sparingly with a wide variety of other ingredients.
Compost it in a pile by itself.
Spread fresh manure across garden beds in fall, allowing it to rot during the winter months.
Spread it across beds that lie fallow six months to one year before planting.
Always wear gloves, shoes, and a dust mask when collecting or spreading manure. Be sure to wash your hands thoroughly and scrub under your nails after handling manure.
Pet bedding: Small pets such as hamsters, rabbits, guinea pigs, and gerbils are bedded down with newspaper, hay, and/or shavings, and this used bedding is a very useful addition to the compost heap.
Feathers: If you don't live near or have access to a poultry farm, you can empty any unwanted feather pillows, down comforters, or feather-filled cushions in your home and mix in the feathers as you fill your compost bin.
Hair and fur: Clean your hairbrush (and Fido's and Fluffy's) over the compost bin. If you're desperate for nitrogen, ask your friendly barber, stylist, or pet groomer to save you a stash when they sweep up.
Hay: Nitrogen content in hay varies depending upon the plants grown and the drying process. A concern to consider before adding hay to your compost pile is its weed content.