Mulch vs. Compost: What’s the Difference?

If you’ve spent any time in a garden, you’ve likely heard about mulch and compost. They’re both essential for a thriving, beautiful garden but they’re not the same thing. In fact, understanding the difference between mulch and compost can dramatically change how successful your garden is.

Let’s dig in!

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What is Mulch?

Mulch is a protective layer of organic matter placed on top of the soil. Its main purposes are to:

• Suppress weeds

• Conserve moisture

• Regulate soil temperature

• Reduce erosion

• Protect soil life
  

Mulch can be made from a variety of materials and common organic mulches include:

• Bark chips

• Straw

• Shredded leaves

• Grass clippings

• Pine needles

• Wood chips
  

Inorganic mulches do exist, although in ecological gardening, organic mulches are preferred because they break down and enrich the soil slowly over time.

Important: Mulch is not usually nutrient-rich itself. Its job is to protect the soil and support the ecosystem above and below ground.

What is Compost?

Compost is decomposed organic matter that’s been broken down by microorganisms, fungi, worms, and insects into a rich, dark, crumbly material. It’s often called "black gold" for a reason because compost is packed with nutrients that feed soil organisms which will give your plants a boost of nutrients and build healthy soil structure.

The main benefits of compost include:

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• Nourishing plants indirectly

• Enhancing soil structure and water-holding capacity

• Introducing beneficial microorganisms

• Balancing soil pH naturally
  

Compost can be made from a variety of materials as well such as:

• Kitchen Scraps

• Yard Waste

• Leaf Mold

• Animal manure

• Worm Castings

Compost is meant to be applied on the surface of the soil, where it can wash into the root zone. Compost’s role is to feed and rebuild the soil rather than simply protect it.

Compost vs Mulch at a Glance

Feature	Mulch	Compost
Primary Purpose	Protect the soil surface	Improve soil fertility and health
Application Method	Laid on top of the soil	Lightly mixed into or applied to the soil surface
Nutrient Content	Usually low, depending on the material	High; feeds the soil food web and plants
Decomposition Speed	Varies; often slow	Often quickly (2-12 weeks)
Examples	Bark chips, straw, and shredded leaves	Finished kitchen scraps, yard waste, and manure

Now that you know the differences between compost vs mulch, it should be clear that for the best garden results, use compost first to build soil health, then apply a mulch layer on top. This combination protects the soil while the compost feeds it, a winning strategy for a resilient, thriving garden.

Mulch is like a protective blanket for your soil. Compost is like a nutritious meal for your soil.

They each play a vital, but different, role in a healthy garden. Learning to use them together, in the right way and at the right time, will help you create vibrant garden beds full of life, beauty, and abundance.