How to Make Your Own Compost

Pile of homemade compost being raked behind chicken wire fence

The Spruce / Meg MacDonald

Project Overview
  • Working Time: 1 - 10 hrs
  • Total Time: 8 wks, 4 days - 17 wks, 1 day
  • Skill Level: Kid-friendly
  • Estimated Cost: $25-200

Any gardener can benefit from adding nutrients and organic matter to the soil to help plants thrive. One of the most popular and beneficial substances to add is compost. Compost will help all your plants grow better, whether your garden is indoors or out. You can purchase compost at any garden supply center, but it is easy (and less expensive) to make your own.

With established perennials, adding a yearly layer of compost over the root zone around plant stems serves the same function as fertilizer and as an amendment that improves soil texture. It also has the added benefit of moderating soil temperature and helping with moisture retention. It reduces or eliminates the need for artificial fertilizers. For plants that require winter cold protection, a thick layer of compost as a mulch will help moderate the freeze-thaw cycles that can destroy the roots of tender plants while improving the soil.

What Is Composting?

Composting is putting organic materials in a pile or container and allowing them to decompose into a form that plants can use as nutrients. You need nitrogen, carbon, and water to create compost. Compost or "black gold" has infinite uses in the garden. It's a soil amendment that adds nutrients and improves the texture of almost any garden soil. Blend compost into garden soil before planting for prolific plant growth.

How to Choose a Compost Bin

When choosing a compost bin, you have to think about how you plan to use the compost and how much you need. Consider if it is for a small indoor garden or larger? Do you have a large outdoor space for the pile or only an apartment?

You can keep a bin in your kitchen. Today’s composters are streamlined and odor-free, offering options to accommodate even the smallest of apartments. There are many styles of compost bins to choose from. You can spend hundreds of dollars buying a fancy outdoor version, which is essentially a barrel with a crank that makes it easy to keep the contents mixed. Or, you can make your own.

Also, instead of a bin, you may want to contain your compost on an outdoor pile for larger amounts. A pile container keeps your pile together. It can be made of any material you have access to, such as:

How Do You Make Compost?

To make a healthy compost pile, you need three ingredients: green material, brown material, and moisture. Green materials are kitchen scraps, coffee grounds, pruning discards from fresh plants, and grass trimmings. Brown materials are fallen leaves, shredded tree branches, cardboard, newspaper, hay or straw, and wood shavings. You will want to maintain a ratio of 50% green material (nitrogen) to 50% brown material (carbon). Spray water on the pile enough to moisten it but do not make it soggy. If it's too wet, it can drown the microbes.

Some items should not be used in compost heaps, including:

  • Meat and fish
  • Dairy, fats, oils
  • Woods treated with preservatives
  • Diseased, pest-infested plants, or invasive weeds
  • Charcoal ash
  • Dog and cat waste

Some items will create a smelly pile, attracting rats and other vermin. Any items treated with pesticides or acidic things like charcoal ash can kill the bacteria in your pile. Dog and cat poop may have harmful bacteria or parasites that turn your fertilizer into hazardous waste.

Avoid putting leaves or other plant parts that show signs of disease or fungal spots. These pathogens may survive the heat of the composting process and be transported back into the garden when you eventually use the compost. Unhealthy plant material should be bagged up and taken away.

To keep your decomposition rate on track, take the pile's temperature using a probe deep enough to get about 2/3 of the way down. Also, take the temperature in several spots. The ideal temperature is 130 to 140 F. If it gets up to 160 F or more, turn the pile to aerate it to bring the temperature down. Any temps above 170 F for more than several hours will stop microbes from working and kill the process. Water the pile if it starts to dry out.

Items you can use to make compost

The Spruce / Adriana Sanchez

How to Care for Compost

A compost pile can be started any time of the year, although, in winter, decomposition will slow down. Just remember that making compost is an ongoing task. It's not something you start, turn once, and then forget for a year. If you keep an out-of-the-way pile of "black gold" going, you'll always have a place to recycle much of your household waste, and you can turn it into something useful.

If your compost heap starts to smell, likely the ratio is off. If the pile is soggy, it has too much water. Other odor-causing issues include adding too many greens and not enough browns or having meats or oils in your heap. Another cause of a smelly pile is the materials are getting compacted and not getting enough air; so, turn it.

Plan on turning your pile every two to four weeks using a pitchfork. If you can, take the pile's temperature every day or every time you go to "feed" your pile. Make sure your compost pile averages about 135 F. Once the pile starts to cool down and the materials turn into a black, crumbly material, then your compost is ready to use in the garden.

Now What?

Now that you have compost, you need to know what to do with it. All answers lead to plant food. It's how you supply it that changes.

  • Fertilizer: Feed your perennials, bulbs, fruit trees, container plants, or lawn. Top dress or sprinkle some on top of your new or established plantings.
  • Mulch: Apply a 3- to 6-inch layer of compost to the soil surface instead of using mulch, it will prevent water evaporation from the soil, keeping it moist longer, and it will also discourage weed growth.
  • Potting soil: To make an enriched potting soil, use equal parts compost, vermiculite, and topsoil, mix thoroughly.
  • Compost tea: Brew compost tea. By making a liquid emulsion, you get a concentrated fertilizer that quickly reaches your plant's roots.

Also, think about the different methods of composting. You have several options, and all give you the same results, although some ways take longer than others.

  • Worm composting: A nice idea for indoor composting is to buy a plastic tub that will fit under your kitchen sink and begin composting with earthworms. This is called vermiculture. Worm composting is best for small-scale, small-batch composting. Small and portable, these composters process household waste in three to six months, producing nutrient-rich worm tea suitable for houseplants and planter boxes. This method doesn't require turning, but you have to balance the conditions so the worms can thrive delicately. Also, this bin needs to be kept in temperatures above 40 F, so the worms don't freeze and die.
  • Compost tumblers: If you have some outdoor space, you can get a compost tumbler, which is larger, much like a small drum with a crank. It is fully sealed to preserve the heat generated by your compost, increasing decomposition speed. Also, since it's sealed, it has no odor, and no outside vermin like rats or raccoons can get into the container. You need to turn the handle to aerate and mix the contents. You can have compost within two weeks.
  • Bokashi composting: Bokashi is a closed system that uses fermentation, bacteria, and a lack of oxygen to break down the compostables. It works in about 30 days. It doesn't yield fertilizer but gives you compost tea. After 30 days, you can remove the food scraps to feed a compost pile, bury it, wait two weeks, unearth it, and be ready to use it as traditional fertilizer.
  • Food digester: Also called a food recycler, these electric-assist composters are technically not composters. They heat, grind, and convert your food waste into dark, dry fertilizer in 24 hours. Some are the size of bread-makers, and others are the size of a standing 13-gallon trash can. These appliances are effective but are pricey and require energy to run. These devices are still an excellent alternative to sending food scraps to landfills or incinerators.

What You'll Need

Equipment / Tools

  • Compost bin or pen
  • Shovel or pitchfork

Materials

  • Organic material such as food scraps

Instructions

  1. Add "Green Material"

    Green material is high in nitrogen. It includes kitchen scraps such as coffee grounds, peelings, fruit cores, uneaten leftovers, and eggshells. Any kitchen waste that is not greasy or meat can be composted. Grass clippings, leaves, and weeds are also considered green materials, as is manure from barnyard animals (but not cats or dogs).

    "Green" materials to add to a compost pile

    The Spruce / Meg MacDonald

  2. Add "Brown Material"

    Brown material is high in carbon. Paper, cornstalks, sawdust, small branches, twigs, and straw all fall into this category. The ratio of nitrogen to carbon should ideally be 50/50 in your compost pile so for every bit of brown material you add, be sure to balance it with green material.

    Tip

    If you add paper, such as newspaper, to your compost pile, shred it first so that oxygen can get at a significant amount of the surface. If you don't take this step, you risk turning moldy and ruining your compost.

    "Brown" materials for a compost pile
  3. Add the Right Amount of Moisture

    Water is the final key ingredient in a thriving compost pile. Without moisture, your pile will take months to do anything and, if dry enough, will not break down at all. If your pile is too wet, on the other hand, it will smell and become slimy as the ratio of harmful bacteria outweighs the good.

    You want the pile to remain damp but not dripping wet. If you do not get enough rainfall to suffice, dump a bucket of water over it once a week to keep things moving. You will know that your compost pile is right if it becomes hot in the middle. Maintaining heat is important to sterilize the compost and kill the weed seeds or harmful bacteria that may be there. The heat is your proof that the ratio is working for your compost pile.

    Watering the compost pile

    Jurgute / Getty Images

  4. Turn Your Compost Pile

    Whether using a compost bin or a simple pile, you will need to turn your materials. This action doesn't have to be anything significant; shovel or fork the outer portion of the pile toward the center and continue shuffling the materials around the pile until you have rearranged it so that fresh compost is now exposed. This way, all the beneficial organisms can have a chance to work on all of the pile's ingredients. A pile will need to be turned every two to four weeks.

    If you have a bin with a crank, give it a few turns every week. If your pile heats up, gets moisture, and gets turned regularly, you should have dark, wonderful compost in about one to two months.

    Compost pile being turned with garden shovel behind chicken wire fence

    The Spruce / Meg MacDonald

Homemade compost added around herbs in garden

The Spruce / Meg MacDonald