Step by Step Guide to Making Garden Compost: How to Turn Organic Waste Into Valuable Soil Improvement Material

To compost at home, mix dry browns like leaves with wet greens like food scraps, keep the pile damp like a wrung-out sponge, and give it air. The EPA says to use two to three times as much brown material as green, by volume. Avoid meat, dairy, oils, pet waste, and diseased plants.

A pile that’s at least 3 feet on each side can heat up fast. University of Maryland Extension says hot composting can give you compost in six to eight weeks. A cool, low-effort pile takes about a year.

Turn the pile when it cools, and add dry browns if it smells. Your compost is ready when it looks even, smells earthy, and no longer feels warm.

This guide walks you through every step, from choosing a method to using the finished compost.

What is composting, and why should you do it?

Composting is controlled rotting. Microbes and soil animals break down plant matter into a dark, earthy material you can feed to your garden. UMD says bacteria, fungi, and other microbes are the key players.

Finished compost improves soil structure, drainage, and water-holding capacity. UMD also says it’s a free soil amendment that saves money on alternatives like peat moss or fertilizer.

It keeps waste out of landfills, too. UMD cites EPA figures that yard waste, food waste, and paper make up a large share of municipal trash, and most of it can be composted.

Step 1: Which composting method fits you?

You have several options, and none is wrong. Pick the one that fits your space and your patience.

Method	Speed	Effort	Best for
Hot pile or bin	Six to eight weeks (UMD)	High	Gardeners with lots of material at once
Cool (passive) pile	About a year (UMD)	Low	Adding scraps as you go
Tumbler	Works well for cool composting (UMD)	Medium	Small yards
Worm bin	Three to six months to harvest (EPA)	Medium	Apartments and food scraps
Sheet composting	Late summer to spring (UMD)	Medium	Building a new bed
Trench composting	Slow, especially in winter	Low	Kitchen scraps in a vegetable garden

The table draws on UMD’s comparison of methods and the EPA’s vermicomposting notes. UMD warns that a tumbler is usually too small for hot composting.

If you don’t want to build a bin, see our guide to making compost without a bin. For a budget bin, see our low-budget DIY compost bin ideas.

Step 2: Where should you put your compost pile?

The EPA lists four location rules. Put it where you can reach it year-round, on ground with good drainage, near a water source, and not right against a fence. It will break down in sun or shade.

UMD adds that you should keep it away from trees. Tree roots can grow into the pile.

Put the pile or bin on bare soil if you can. That lets worms and other soil organisms in.

What can you compost?

Every pile needs two kinds of material. Browns supply carbon, and greens supply nitrogen. UMD says microbes use carbon for energy and nitrogen for growth.

Browns (carbon)	Greens (nitrogen)	Leave out
Dry leaves	Fruit and vegetable scraps	Meat, fish, and bones
Shredded paper or cardboard (no wax, tape, or glue)	Grass clippings (untreated)	Cheese, milk, and other dairy
Straw and hay	Coffee grounds and paper filters	Fats, oils, and grease
Wood chips and sawdust	Crushed eggshells	Pet waste and cat litter
Plant stalks and twigs	Manure from cow, horse, poultry, sheep, or rabbit	Diseased or pest-infested plants
Pine needles	Seaweed	Herbicide-treated plants and grass

This table combines the EPA and UMD lists.

Two extra cautions from UMD. Check tea bags, because many contain plastic and shouldn’t go in the pile. And skip large amounts of wood ashes, since they alter the pH.

The EPA also says compostable bags and foodservice ware often won’t break down in a backyard pile. The reason is that backyard piles don’t reach high enough temperatures.

For kitchen-scrap ideas, see our list of kitchen waste compost tips.

Step 3: How do you build the pile?

Build the pile all at once if you can. Make it at least 3 by 3 by 3 feet, and no taller than 5 feet.

Start with a 4- to 6-inch layer of bulky browns like twigs and wood chips. Then add browns and greens, using two to three parts browns to one part greens by volume.

Chop or shred big pieces first, since they break down slowly. Cover food scraps with 4 to 8 inches of dry leaves or other browns. Skip lime, which can release nitrogen as ammonia and rob the microbes.

Step 4: How wet should compost be?

Keep the pile as damp as a wrung-out sponge. Squeeze a handful to check.

Too much water makes the pile smell. In dry weather, water it about once a week.

A tarp keeps heavy rain off and holds moisture in. Oregon State Extension puts the right level at about 60 to 65 percent moisture.

Step 5: When should you turn the pile?

Turn the pile with a garden fork, moving the outside toward the middle. Do it when the pile cools, before it drops below 100°F.

Check the heat with your hand. If the pile feels at least as hot as hot tap water, leave it alone. If it feels cool, turn it.

A compost thermometer makes this easier.

A healthy pile heats up within about a week and reaches 130 to 135°F. That heat kills most weed seeds and pathogens. Don’t turn the pile in winter, because heat escapes.

Step 6: How do you fix common compost problems?

Most problems come down to air, water, or balance. Use this chart.

Problem	Likely cause	Fix
Rotten-egg or sour smell	Too wet, or not enough air	Turn it and add dry browns like straw, leaves, or shredded paper (Oregon State)
Ammonia smell and heat	Too much nitrogen	Add more carbon (UMD)
Pile isn’t heating	Not enough nitrogen, or too small	Mix in fresh grass clippings, manure, or fertilizer (Illinois Extension)
Dry center	Not enough water	Moisten and turn it (Illinois Extension)
Damp only in the middle	Pile is too small	Collect more material and mix the old pile into a new one (Illinois Extension)
Big pieces won’t break down	Low surface area	Remove them, then chop or shred (Illinois Extension)
Rodents or flies	Wrong scraps, or exposed food	Skip meat, dairy, and fats, bury fresh scraps, and line the bin with hardware cloth (Oregon State)

The Illinois Extension troubleshooting guide is where the causes and fixes for a cold, dry, or small pile come from. For more, see our page on common compost problems.

Don’t panic about bugs. UMD says earthworms, slugs, millipedes, sow bugs, ants, and insect larvae do the first breakdown of coarse material.

Step 7: How do you know compost is ready?

UMD gives three checks. The material should be even in color and texture with an earthy smell and no off odors.

The pile should be at outdoor temperature. And a small amount sealed in a plastic bag should cause no condensation inside.

For a hot pile, UMD says to keep turning and checking until the volume is about 50 percent of the original. Then let it sit for two weeks to cure. Curing helps stabilize the nutrients.

Step 8: How do you use finished compost?

Pick the use that fits your garden.

• Soil amendment. Mix 2 to 4 inches of compost into the top 6 to 9 inches of soil.
• Mulch. Spread a 3-inch layer on the surface, a few inches away from stems and trunks.
• Potting mix. Blend 50 percent screened compost with 50 percent commercial soilless growing media for transplants and containers.
• Compost tea. Steep one part compost in five parts water for one to three days. Strain it, then apply it to plants. Don’t use farm animal manure compost for tea.

For more mulch ideas, read our guide on why to use mulch in the garden.

Where do the experts disagree, and what should you do?

Extension sources differ on a few details. None of them decides whether your compost works. Here is each one, with the choice we made in the steps above.

Detail	What sources say	What we chose
Layering or mixing	Layer like lasagna (EPA), or mix thoroughly because layering usually isn’t helpful (UMD)	Start with a bulky base, then add materials in the right ratio
Pile size	At least 3 by 3 by 3 feet (UMD), or 0.5 to 1 cubic yard in peak season (Oregon State)	3 by 3 by 3 feet, which is about 1 cubic yard
When it heats	Within 24 hours (UMD), or within a week (Oregon State)	Expect heat within a week
First turn	Before it drops below 100°F (UMD), or after the first 3 to 5 weeks (Oregon State)	Turn when the pile feels cool
Heat that kills weed seeds	130 to 135°F (Oregon State)	130 to 135°F
Mulch depth	2 inches (UMD), or 3 inches (EPA)	3 inches

What if you have a small space or no yard?

You can still compost. The EPA says worm composting takes up little space, uses simple materials, and can be done indoors or outdoors. Harvest comes after three to six months.

Read our guides to indoor composting methods, the beginner’s guide to vermicomposting, and how to start worm composting.

A countertop bin keeps scraps handy between trips to the pile. Mix in dry material, such as leaves or shredded paper, to reduce odor, per UMD.

What do people get wrong about composting?

Most failures repeat.

Too many greens. A pile of only food scraps turns wet and smelly. Add more browns.

Too small a pile. Oregon State and Illinois both point to size as a reason piles stay cool or damp in the middle.

Wrong scraps. The EPA says meat, dairy, and grease attract animals, so keep them out.

Never checking moisture. Piles dry out in summer and drown in rain, and both stop the process.

Turning in winter. UMD says it lets heat escape.

We’d start small. A single bin and a bucket of browns beats a perfect plan you never build.

Frequently asked questions

How long does composting take?

It depends on the method. UMD says hot composting can give a harvest in six to eight weeks, and a cool pile needs about a year.

Can I compost in winter?

Yes, but it slows down. UMD says not to turn a pile in winter, and that trench composting slows significantly from November through March.

Do I need worms to compost?

No. UMD says microbes do the main work, helped by soil animals that break down coarse material. Worm composting is a separate method, and the EPA says harvest takes three to six months.

Can I compost eggshells, coffee grounds, and tea bags?

Yes to eggshells and coffee grounds, per the EPA. For tea bags, UMD says many contain plastic, so empty the leaves and throw the bags away unless they’re plastic-free.

Why does my compost smell bad?

Usually it’s too wet or short on air. Oregon State and Illinois Extension say to turn it and add dry browns.

Will compost attract rats?

It can if you add the wrong scraps. Oregon State says to skip meat, fish, fat, oil, dairy, and bones, bury fresh scraps, and line the bin with hardware cloth. The EPA also says food scraps need a cover of browns.

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