9 Types of Garden Debris to Add to the Compost Pile

You have a compost pile and wonder what to put in it. The truth is you can put mostly anything in it, as long as it’s organic and decays readily. Some sites warn against putting meat and dairy in your piles, but you can even put these and animal carcasses in to rot, albeit with some extra considerations.

Once you know exactly what you can decay using composting, you’ll be able to come up with an efficient system for managing garden waste. Plant clippings redirect from yard waste bins into compost, and kitchen scraps turn from rotting trash into humus-rich soil. You’ll start saving money with less waste by creating free soil, and if you cancel your yard waste bin charge. 

Whatever your reasons for composting, you’re doing honorable work by participating in this natural process. You’re actively moving waste from landfills into the natural environment and fostering fungi, bacteria, and worms in your piles. Help your plants, ecosystem, and local wildlife by composting these nine types of garden debris.

Kitchen Leftovers

Although they come from the kitchen, food scraps are on this list because fruits, vegetables, and grains originate from the soil. This is some of the best garden debris to use in the compost. Plants suck up nutrients, convert them into carbohydrates, and pump their fruits and grains full of them. Then, after we eat most of the flesh, we can return the leftovers to garden soils so they convert waste back into soil nutrients. 

Eggshells, coffee grounds, and teabags without woven plastic are ideal for piles. Other items like rice, beans, veggie cuttings, fruit slices, and homemade bread decompose successfully with regular pile turning. The key to wet kitchen leftovers is balancing them with brown materials like straw, paper, or small pieces of wood. 

Use a ratio of one part greens to three or four parts browns (by volume) in your hot or cold compost pile. Greens are things like kitchen leftovers, grass clippings, and garden scraps. Browns are straw, paper, dry leaves, or small pieces of wood. This ratio ensures things like rotting vegetables decay quickly before they can attract wild animals. 

Meat and Dairy

Most guides recommend leaving dairy and meat products out of compost, as they attract voracious wildlife with their decaying aroma. Small pieces of meat and dairy are fine, so long as you aren’t regularly adding large steaks to your piles.

A pile with larvae, worms, and microbes decays all organic waste types—these creatures only eat so fast, though, and you don’t want to overwhelm them with meat and dairy. Composting too much meat can pose food safety risks as well.

Add no more than a few scraps here and there to your piles. If you notice animal disturbance or the meat decays slowly and develops a stench, reduce how much you add until the microbes can eat the existing debris. Another note on meat and dairy is that they’re best for hot compost piles, not cold ones. Bury these scraps at least a foot below the ground level as an alternative.

Grass Clippings

Another perfect compost input is grass clippings (mower debris) from your garden pathways or your lawn. Grass clippings are excellent nitrogen boosters for slow-working piles. They decay quickly, leaving nutrients for microbes to consume. More microbes and worms mean more decomposition, which leads to faster composting. 

Instead of dumping lawn clippings into yard waste bins or bags in the trash, put them directly into your compost and turn the pile well with a pitchfork. They’ll turn into humus-rich mulch in a few days or weeks. 

Grass works well as a mulch for garden pathways and a fertilizer booster on existing lawns. Scatter the waste over your paths for mulch.  With a mulching plug on your lawn mower, you’ll feed grass waste back into the lawn instead of collecting it into a bag. It’ll break down, feeding your grass and the living creatures below the soil. 

Garden Scraps

Garden scraps abound after the summer growing season. Herbaceous perennials, annuals, and tender perennials leave dying stems, leaves, and roots that make excellent composting material. Green, fleshy parts count as greens, and dry plants without moisture are brown materials. 

Some diseases appear regularly in our gardens, like powdery mildew, bacterial leaf spot, or mosaic viruses. If making a hot pile, you can put diseased clippings in it, but ensure you know the disease you’re dealing with. Some diseases persist even in hot compost piles. Most importantly, cold piles may not kill diseases or pests fully and can spread them when you apply your compost as mulch.

Similar to meat and dairy, you may bury certain infected plants a foot below the soil. They’ll struggle with good bacteria, fungi, and other microbes that battle them for space and nutrients. You’ll snuff them out before they break through the soil layer and infect more precious plants.

Paper Products

While not technically garden debris, leftover paper from your daily life can make a great compost input as long as it’s non-toxic. Paper is tree pulp that forms a fine, thin sheet. Some papers are biodegradable without synthetic chemicals, while others are chock full of processing materials. Look at paper products’ labels to determine if they have extra things like bleach, whitening agents, or sterilizing chemicals.

Cardboard is also a paper product and easily compostable. Be sure it’s free of synthetic ink, glossy print, or stickers before adding it, as these things can harm living creatures and microbes in compost. Use chemical-free cardboard or paper for best decomposition results. 

Paper products are brown compost materials, working like straw, fallen leaves, or twigs. Most of them with synthetic inks and sprays are recyclable in cities with recycling plants. Consult your waste company’s guidelines to determine where to put your uncompostable paper waste.

Straw

Straw, like paper, is a brown plant debris that adds carbon and structure to your compost piles, in addition to many other garden uses. It is made of the leftover stems, leaves, and chuff from grass harvests. Farmers pack them into bails for animal bedding or they bag it up and sell it as a garden amendment. You may have lots of straw if you cultivate oats, wheat, or rye, or if your neighbors or friends are farmers.

Straw is an excellent compost addition and a perfect material for organic mulch. It’s slower to decay than fresh grass clippings, making the ground dry and compact for easily walkable pathways. It does break down faster than wood chips, so you’ll have to apply straw mulch once or twice a growing season as it decomposes. 

Straw benefits compost with the air holes in its stems—they allow microbes to breathe while they consume food waste and garden scraps. The stems act as air pockets within dense, rotting compost. Straw may have seeds, so watch your pathways for seedlings. However, there are plenty of weed-free options out there. If any sprout, pull them up and let them decay atop the straw.

Fallen Leaves

While commonly seen as annoying yard debris, leaves are one of the most underrated garden and compost inputs. Can you believe how many people put this golden resource out by the curbside?

Mild autumn temperatures and regular rainfall push deciduous trees to dump their leaves. All these dry leaves are incredibly beneficial for soil, compost, and existing shrubs. They, like straw and paper, contain carbon. Shrubs and trees use carbon to create wood, while fleshy perennials and annuals use less of it to make their green parts. 

Instead of raking, blowing, and throwing these nutritional powerhouses away, use them to create leaf mold or compost. Leaf mold is like compost, except it consists entirely of dead leaves. This amendment takes longer than hot piles to break down, but it’s a spectacular addition for carbon lovers like pine trees, woody shrubs, and maples. 

Like straw and grass clippings, fallen leaves act as an organic mulch when you apply a thick layer on top of the soil. This process occurs naturally in forests as deciduous trees drop their leaves to the floor during fall. They stay there, creating a cozy home for soil organisms as they eat the decaying leaves. Walk into a forest and brush some of the leaves on the floor—you’ll find fertile, crumbly, humus-rich soil underneath.

Twigs and Branches

Twigs and branches are like garden scraps, except they’re woody brown materials. They add structure to piles, helping air and moisture travel through. They also add carbon and other nutrients as they decay, feeding fungi, bacteria, and algae within your compost. 

Large branches will take much longer to decompose than thin twigs. Use a wood chipper to make small chunks. I’m guessing most of us don’t have wood chippers, though! I use an electric chainsaw or branch loppers to break up large pieces of wood into smaller ones. If the branch is smaller in diameter than your largest finger, then it’s good to add. 

Too much wood can slow down composting rates. Wood sucks up nitrogen as it decays, causing a temporary nutritional imbalance in your pile. Adding an equal ratio of browns like twigs and greens like grass clippings ensures your composting occurs at a regular speed.

Pine Cones

Do you have an evergreen conifer in your yard? Chances are you also have lots of pine cones if you do. They fall by the dozens to spread conifer seeds. When the seeds fall out, these wooden cones are empty and seemingly useless. They aren’t useless, though, as they’re a wonderful brown material to add to compost for carbon and structure.

Add pine cones in an equal ratio to green materials like kitchen leftovers or fresh plant parts. Pine cones are wooden, which means they suck up nitrogen as they initially break down. Bolster your pile with green and brown materials in equal ratios, and it’ll decompose pine cones without issue.