Knowing what you can and can’t compost is important when you want to generate your own amazing nutrient -rich soil, and become a no-waste home.
Most gardeners know that the best soil you can get will really ramp up your garden. And what is the best soil you can get? Compost. Compost has tons of macro- and micro-nutrients which are vital to your plant’s survival. Absence of these elements, especially the macro-nutrients, and your plants will be susceptible to diseases and struggle to survive.
Compost provides much better nutrients than average soil, because as your kitchen and garden scraps and vegetables break down, the nutrients from many different plant matters becomes part of the soil, creating a much more rich nutrient growing medium.
What you Can and Can’t Compost
The fertilizer industry arose because many soils are lacking in one (or more) of the big three macronutrients; nitrogen, phosphorus, or potassium. These three elements make up the basis for an entire industry. All fertilizer labels have three numbers in bold on their labeling, which is the amount of these three nutrients in the package. Instead of purchasing expensive fertilizers, you can generate soil which has these macronutrients already in it.
In addition to adding plant nutrition to your soil, compost provides a good consistency for root penetration and water retention. And because it is newly digested plant material, all of those beneficial organisms are still likely hanging around in the soil, working their wonders.
Mixing certain types of compostable materials and changing the proportions of “browns” (carbon) and “greens” (nitrogen) makes a big difference in the speed of your compost pile turning to rich soil.
Here is the list of what you can and can’t compost, broken into green and browns.
What You Can Compost
Green Matter
- Any kitchen vegetable or fruit scraps, rinds, peels, and vegetable cuttings
- Old or spoiled fruit, vegetables or potatoes
- Leftover cooked vegetables or fruit with no oils, butter, sauces or sugar
- Eggshells
- Brewed coffee grounds, coffee filters, stale coffee
- Tea and tea bags
- Grass clippings
- Shrimp shells, crushed lobster or oyster shells – excellent source of chitin and calcium!
- Leftover pumpkins and gourds after halloween. You may wish to de-seed them otherwise the seeds could sprout either in the compost, or later in the processed soil once you start watering it. This is common in piles which don’t reach a high internal temperature.
- Healthy garden clippings
- Chicken and rabbit droppings from cleaning the coop or hutch
- Dead flower bouquets
- Pond algae – if you have a pond, your compost is gonna be awesome!
Brown Matter
- Leaf mulch, leaf litter, or any brown leaves
- Cornhusks and cobs are ok – but they could take longer to decompose
- Stale dried spices
- Nut shells, except walnuts
- Raffia
- Pressed paper egg cartons and brown paper bags
- Shredded paper and paper towels, including your old taxes. How satisfying is that?
- Shredded newspaper, cardboard and non-glossy junk mail
- Wood shavings, straw or hay bedding
What you Should Not Add to your Compost Pile
- Milk, dairy, cheese
- Breads, pasta, rice
- Meat, bones, fat, oils or any meat products
- Weeds (these could sprout new weeds if the compost doesn’t reach a certain internal temperature – which you don’t want in your soil)
- Diseased plants or cuttings such as rose leaves with rust or blackspot. Funguses like rust can live dormant in the soil for many years and then spread.
- Any plant matter treated with pesticides
- Walnuts or walnut shells, black walnut tree leaves or clippings. Walnut trees contain a compound which inhibits the growth of many plants.
- Charcoal ash. Charcoal has chemicals in it which will not break down.
- Sawdust, especially from treated wood. Sawdust has too much carbon and fails to break down in a home compost pile. Small quantities are ok, but larger quantities, like from a home workshop, will create a carbon void in a small home compost pile.
- Sticks or wood chunks. They can take significantly longer to break down.
This is my list of what you can and can’t compost. It may differ from some out there because of nutritional value or speed of decomposition. Do you have any items you think should be added to the list? Let me know in the comments below!
