Organic mulches are like a healthy picnic for your lawn. They blanket your lawn and feed your soil (with nutrients and organic matter, not watermelon cubes and pinwheel sandwiches!). While any mulch, inorganic or organic, will protect your soil from erosion and weed growth, only organic mulch will give your plants the extra nutrients they’re craving.
Let’s dig into the 10 best organic mulches for your yard.
What is mulch?
Mulch is a material you spread across your landscape to prevent weed growth, reduce erosion, keep soil temperatures stable, and retain soil moisture for healthy plant growth. Mulching is an essential gardening practice that both protects your soil and strengthens the plants and tree roots that grow in it.
When you use mulch, you don’t have to water, weed, or aerate your garden and flower beds as frequently, and you don’t have to worry about your plant roots heaving out of the soil due to repeated freezing and thawing.
Plus, the right mulch will give your landscape an elegant flair that’ll make your neighbors “ooh” and “aah.”
Organic vs. inorganic mulch
There are two types of mulch: Organic and inorganic. Organic mulches are made out of natural materials that decompose, like wood bark, shredded leaves, pine needles, or grass clippings. Inorganic mulches are made out of materials (either natural or synthetic) that do not decompose, like stones, gravel, black plastic, or landscape fabric.
For organic mulches, the decomposition of organic matter is both a blessing and a curse. As organic material decomposes, it improves soil texture and fertility, adding valuable nutrients to the soil and attracting earthworms and beneficial microbes.
But this decomposition process also means that organic mulch doesn’t last as long as inorganic mulch. It needs to be replaced every year or every few years, depending on the mulch material.
If you primarily want to protect plant roots and improve your soil, organic mulch is the way to go. If you want to give your lawn a sleek, aesthetic design without the weeds and upkeep, inorganic mulch is ideal.
10 types of organic mulch
Organic mulch is fantastic for your lawn, and it doesn’t have to cost a cent. You can use your own yard waste (like grass clippings and pine needles) as a nutrient-packed lawn amendment, or you can get free tree mulch from arborists or utility companies in your area.
1. Compost
Compost is every gardener’s dream soil amendment. It’s a nutrient-rich mixture of decomposing organic matter — from table scraps to fallen leaves to grass clippings — and you can make it all by yourself. Compost protects roots, insulates soil, and amends soil texture and quality. The result? A garden filled with healthy soil and flourishing plants.
Compost:
- Feeds and gives a habitat to beneficial bacteria, fungi, microorganisms, and worms. In turn, these organisms rapidly break down organic matter and release chemicals that prevent plant diseases.
- Improves your soil’s ability to retain moisture and nutrients.
- Improves aeration in clay soils.
If you’re creating your own compost, avoid tossing in meat; bones; foods with a high fat content (like cheese, salad dressings, or oils); diseased plants; tough weeds; or animal waste.
Where to mulch: Compost is one of the best mulches for vegetable gardens and flower beds, and it’s a great protective layer around trees and bushes.
Layer depth: 2 to 3 inches
Pro Tip: Compost (and most mulch) is terrific for tree roots, but never apply it directly around tree trunks. Spread mulch 3 to 6 inches away from the trunk to prevent internal rot, disease, and plant death.
| Pros of compost | Cons of compost |
| ✓ Excellent erosion resistance ✓ Easy to DIY ✓ Gives plants a strong nutrient boost ✓ Great for organic gardening ✓ Reduces the need to aerate ✓ Breaks down rapidly to increase soil nutrients ✓ Prevents plant diseases | ✗ Not as good at suppressing weeds as wood mulch and pine needles ✗ Takes time: Requires a waiting period as mulch material decomposes ✗ May release an unpleasant odor (during the decomposition process) ✗ Can attract pests (raccoons, rats, ants, and earwigs) |
2. Tree bark
Tree bark mulch is the cream of the crop when it comes to preventing wind erosion, resisting soil compaction, and suppressing weeds and diseases — but it costs a pretty penny.
A natural by-product of the lumber and paper industries, tree bark comes in many varieties of hardwood and softwood, with sizes ranging from finely shredded to larger nuggets. Bark mulches of all colors (both natural and dyed) are easy to find at local garden centers and home improvement stores.
Want a long-lasting mulch that releases nutrients slowly? Go with large softwood bark chips (like cedar, fir, or pine). Shredded hardwood bark (made of oak or a mixture of hardwoods) needs to be replaced more frequently.
If you have acid-loving plants like blueberries, rhododendrons, hydrangeas, or azaleas, pine bark is an excellent choice.
Where to mulch: Tree bark is perfect on slopes, around trees and shrubs, and in perennial beds. Avoid mulching in vegetable or annual flower gardens.
Layer depth: 2 to 3 inches
Pro Tip: Use aged or cured wood, when possible. Fresh tree bark is less expensive, but as it decomposes, it takes up nitrogen near the top of the soil, which can lead to a nitrogen deficiency in small plants. If you choose fresh bark, apply fertilizer to increase the nitrogen available to your plants.
| Pros of tree bark | Cons of tree bark |
| ✓ Excellent resistance to compaction ✓ High resistance to wind erosion ✓ Strong weed control and disease resistance ✓ Available in many attractive colors ✓ Long lifespan | ✗ Large bark chunks can impede the spread of plants ✗ Can form a crust and prevent water from reaching soil ✗ Aged bark chunks can be expensive ✗ Can attract termites or roaches around house foundation |
3. Wood chips
Wood chips (AKA arborist mulch or municipal tree waste) are excellent at suppressing weeds and preventing erosion, and they look gorgeous doing it. While aged bark is sold in bags at garden centers, you can get wood chips for free from local arborists and tree recycling centers. Wood chip mulch looks lovely around trees, pathways, and perennial gardens.
Wood chips contain tree bark, inner wood, and sometimes even leaves. This variety of textures and sizes reduces compaction and increases biological diversity to improve soil and plant health in the long term. Larger wood chips have a long lifespan (two to three years), while small wood chips decay quickly.
A drawback to the “free mulch” pull? Wood chips are rarely tested and may contain pesticides and herbicides that can harm your garden plants and ecosystem. Fresh wood also tends to tie up nitrogen in soil, which can lead to a nitrogen deficiency at the soil surface. Wood chips steal nitrogen from vegetables and annual flowers.
Where to mulch: Wood chips work well around trees, bushes, and footpaths. They visually complement pine needles for a woodsy aesthetic. Avoid applying fresh wood chips in vegetable or annual gardens.
Layer depth: 1 to 3 inches
| Pros of wood chips | Cons of wood chips |
| ✓ Inexpensive or free ✓ Readily available and easy to find ✓ Excellent resistance to compaction ✓ High resistance to wind erosion ✓ Long-lasting | ✗ May contain harmful pesticides ✗ Can form a crust that prevents water from filtering into the soil ✗ Textures and colors vary: Pieces are not uniform ✗ Can attract termites or roaches around house foundation |
4. Leaves
Partially decomposed leaves (AKA leaf mold) control weeds and decompose quickly, giving your yard a nutrient jumpstart. They improve soil structure, add organic matter, and increase your soil’s water retention so it can tolerate droughts better.
The “decomposed” element is important here, though: If you spread fresh leaves, you’ll just get a thick, wet leaf mat that doesn’t let water filter through.
If you can’t wait for leaves to decompose, apply coarsely shredded dry leaves. Shred leaves with a mower or shredder, but don’t shred too finely: Small leaf particles won’t allow water to penetrate. Dry leaves give pollinators like queen bees and butterflies a cozy home in winter.
Dry leaves suppress weeds well, but they won’t prevent compaction. If your soil is clay-heavy or otherwise prone to compaction, choose a wood mulch instead or mix leaves with straw.
As leaves decompose, you can dig them into the soil and add a new layer of mulch. Avoid adding leaves infected with anthracnose, scab, or leaf spot, as they can spread disease to your lawn. And don’t accidentally add leaves from black walnut trees: They contain juglone, which can harm vegetable plants like peppers, eggplants, tomatoes, and potatoes.
Where to mulch: Leaf mulch is a great general yard and garden mulch. It works well on turf and around trees and bushes.
Layer depth: 2 to 3 inches
Pro Tip: Leaf and straw mulches can attract rodents, so spread them at least 6 inches away from the base of trees and shrubs. You don’t want a chipmunk nibbling on your favorite oak!
| Pros of leaves | Cons of leaves |
| ✓ Inexpensive ✓ Easy to access ✓ Decompose quickly to improve soil ✓ Habitat for beneficial insects in winter ✓ Certain leaves (oak and beech) are great for acid-loving plants | ✗ Poor resistance to compaction ✗ Dry leaves blow away: Poor resistance to wind erosion ✗ Wet leaves can form a mat ✗ Can spread diseases ✗ Can attract rodents ✗ Fire hazard |
5. Grass clippings
Dry grass clippings prevent weed growth and decompose quickly, providing plenty of nutrients to your soil — and you can easily save money by using your own lawn mower scraps. They’re a favorite with thrifty, eco-friendly homeowners.
Just make sure your clippings are dry and were healthy prior to cutting: Wet clippings can form a mat and prevent water from filtering into the soil, and diseased clippings can bring pathogens into your new garden.
One pro tip to avoid a stinky, wet layer of grass clippings? Apply a thin layer of grass clippings and wait for them to dry before applying a second layer. Repeat this until you’ve reached your ideal mulching height. If grass clippings start to smell, fluff them up with a garden fork.
Avoid using grass clippings directly treated with herbicide, as harsh chemicals can harm sensitive plants. If your yard has been treated with a mild herbicide, mow at least three times before using grass clippings. If your yard has been treated with a harsh herbicide like 2,4-D or Banvel, you’ll have to wait months before your grass clippings are usable.
At the end of the growing season, fold grass clippings into your soil.
Where to mulch: Turfgrass, annual flower and vegetable gardens, and perennial beds benefit from grass clippings.
Layer depth: 2 to 3 inches
Pro Tip: If you’d rather reuse grass clippings on the spot, a mulching mower will recycle your clippings back onto your lawn. These clippings filter into the spaces between grass plants and decompose, improving soil health.
| Pros of grass clippings | Cons of grass clippings |
| ✓ Easy to spread ✓ Free and easy to access ✓ Eco-friendly: You’re recycling your own lawn nutrients ✓ Decompose rapidly to give your soil nutrients | ✗ May contain harmful herbicides or weed seeds ✗ Poor resistance to compaction ✗ May look messy ✗ Can form a water-resistant mat ✗ Can spread diseases |
6. Pine needles
Pine needles, also known as pine straw, are airy and light, but they’re also tough: They interlock to stay in place, so they’re perfect for slopes and ridges. They’re springy and resist soil compaction so you can cut back on aerating your lawn.
Pine needles are excellent for acid-loving garden veggies like tomatoes, celery, cauliflowers, and carrots. They have a long lifespan (two to four years), release a pleasant aroma as they age, and won’t form a water-resistant crust like wood mulches tend to do.
Don’t worry about pine needles permanently acidifying your soil. As they decompose, they neutralize.
Where to mulch: A thick layer of pine needles is perfect in annual, perennial, and vegetable garden beds and around acid-loving trees and shrubs.
Layer depth: 3 to 4 inches
| Pros of pine needles | Cons of pine needles |
| ✓ Excellent resistance to compaction ✓ Reduces the need to aerate ✓ Long lifespan ✓ Visually appealing ✓ Inexpensive or free | ✗ Can be a fire hazard ✗ Can prevent water infiltration if layer is too thick |
7. Straw
A thick layer of straw mulch is an excellent choice for vegetable gardens, annual beds, and newly seeded lawns. Straw is the dry, hollow stalks of grains after they have been harvested. While straw may not be the most attractive mulch, it keeps soil moist and insulates soil in winter, making it a favorite among farmers.
You can choose from a variety of straw from wheat and timothy to oat, rye, and barley. Get your straw from a reputable provider so it doesn’t come with weed and grain seeds.
The downsides to straw? A thick layer of it gives unwanted rodents the perfect hiding place. And if you apply a thin layer, it’s prone to blowing away in the wind. Straw’s rapid decomposition also means that you’ll have to apply it more frequently than wood mulch.
Where to mulch: Straw will give your vegetable beds and freshly sown lawn a healthy layer of protection. If you’re growing potatoes for a kitchen garden, spread straw where you would ordinarily hill them to increase your harvest. Straw is highly flammable, so do not apply it near a fire pit.
Layer depth: 3 to 4 inches
Pro Tip: Always use straw rather than hay. Hay’s weed seed content makes it a poor choice for effective mulching.
| Pros of straw | Cons of straw |
| ✓ Excellent resistance to compaction ✓ Reduces the need to aerate ✓ Inexpensive ✓ Readily available ✓ Regulates soil temperatures in winter | ✗ May contain weed or grain seeds ✗ Easily blows away ✗ Can attract rodents ✗ Not visually appealing ✗ Fire hazard |
8. Aged sawdust
Aged sawdust is inexpensive and easy to find, and it’s a special treat for your acid-loving plants. It’s excellent at preventing weeds, but it ties up soil nitrogen as it decomposes, which can lead to a nitrogen deficiency at the soil surface.
To prevent a nitrogen deficiency, mix nitrogen fertilizer with your sawdust or apply fertilizer directly after you spread sawdust. Always opt for sawdust that has weathered for at least a few months; fresh sawdust (AKA green or raw sawdust) is a notorious nitrogen thief.
Before you fall in love with sawdust as a mulch, check your plant health and soil pH. Test a portion of your area with a light layer of sawdust and make sure plants don’t show symptoms of nitrogen deficiency (pale green or yellow leaves and slow growth). If spreading sawdust around sensitive annuals, be cautious: They’ll probably need fertilizer.
Sawdust is prone to caking, which can prevent healthy water infiltration. Fluff up your sawdust every spring to keep soil healthy, and break it up when you notice it beginning to form a mat.
Where to mulch: Sawdust is a great addition around walkways and acid-loving shrubs and trees. Just remember to spread it 3 to 6 inches away from the trunk to keep your tree safe.
Layer depth: 2 to 3 inches
| Pros of sawdust | Cons of sawdust |
| ✓ Excellent weed suppressor ✓ Readily available ✓ Great for acid-loving plants ✓ Inexpensive | ✗ Compacts easily ✗ Can form a water-resistant mat ✗ Uses nitrogen as it decomposes ✗ Blows away in the wind ✗ Can attract termites |
9. Cocoa hulls
Cocoa bean hulls are an aromatic, attractive byproduct of chocolate that can beautify your flower garden. With a striking deep-brown hue, they’re perfect if you want a “wow” factor. Cocoa hulls decompose quickly and are lightweight and easy to apply, but they tend to be pricier than other organic mulches.
Don’t place cocoa hulls in a pet-accessible area: They contain theobromine, which is toxic to dogs.
Make sure cocoa hulls aren’t left wet for an extended period. Dampness can attract pests like jumping worms and cheese skippers.
Mold may form on the surface of your cocoa hulls: Simply stir them to break the surface crust, and mold will dissipate.
Where to mulch: Cocoa hulls are an appealing addition to annual gardens and weed-prone areas.
Layer depth: 1 inch
| Pros of cocoa hulls | Cons of cocoa hulls |
| ✓ Excellent compaction resistance ✓ Reduces the need to aerate ✓ Strong weed suppression ✓ High visual appeal ✓ Long-lasting | ✗ Expensive ✗ Toxic to pets if consumed ✗ Can form a crust on the surface ✗ Wet hulls can attract pests |
10. Ground covers
Want instant greenery without the hassle of spreading mulch? Ground covers smother weeds and keep soil pores open to stop compaction. Their dense root structures prevent erosion, insulate soil, and reduce evaporation. In other words, ground covers are the perfect living mulches.
Many ground covers attract pollinators and create a beautiful habitat for native animals and insects, so you can enjoy a lovely butterfly show while enriching your soil.
Take a trip to your local garden store and pick out hardy, attractive ground covers like liriope, pachysandra, rosy pussytoes, creeping jenny, or periwinkle (AKA creeping myrtle). Check the invasive status of the ground cover you want: Some grow a bit too well in certain states. It’s a good idea to call your cooperative extension office before planting.
Where to mulch: Plant ground covers in shady, dry areas where grass fails to grow and on slopes and hilly areas where erosion is a problem. Don’t plant them in your vegetable or flower garden: They’ll compete with your veggies for water and nutrients and smother your flowers or veggies.
If you want the benefits of both non-living mulch and ground covers, you can plant ground covers within your mulch bed or you can mulch around planted ground covers.
| Pros of ground covers | Cons of ground covers |
| ✓ Excellent erosion resistance ✓ Roots resist compaction ✓ Perennials don’t require frequent replacement ✓ Reduce the need to aerate ✓ Low maintenance compared to other plants ✓ Attract pollinators | ✗ Require more maintenance than non-living mulch ✗ Individual plants can be expensive ✗ Can compete with desired plants for nutrients ✗ Take time to establish ✗ Can be invasive |
FAQ about organic mulch
Yes, but make sure you fluff the old mulch before adding the new to prevent compaction.
Before adding new mulch, check your mulch depth: Your mulch layer should never be higher than 4 inches, so you may need to remove some old mulch before layering fresh mulch.
Leaves will be ready six to 18 months after starting the composting process. The end product will be dark brown, rich, and friable (easy to crumble).
You may need to strain out larger pieces that need more time to decompose. Break them into smaller pieces and add them to another active compost pile.
Organic mulch…
—Keeps soil moist
—Prevents soil compaction
—Prevents weed growth
—Encourages extensive root growth
—Protects trees and shrubs from mowing damage
—Reduces wind and rain erosion
—Prevents the spread of soil-borne diseases
—Adds visual appeal
—Keeps soil temperatures stable
—Invites beneficial microorganisms and earthworms
—Increases soil nutrient levels for lasting plant health
—Improves soil texture and structure
Throwing an organic picnic for your landscape
Ready to throw a picnic for your soil? You can find organic mulches at your local gardening or home improvement store, or use your own grass clippings, pine needles, or compost. If you’d rather leave the party planning to a pro, call a local lawn care team to get your lawn looking its finest.
Main Photo Credit: kiora_geta | Pixabay
