Harbor Soils

Bark vs. Mulch: What's the Difference and Which Should You Use?

Sam Roe

• 2 min read

Walk into any garden center in Kitsap County and you'll see "bark" and "mulch" used interchangeably. They're not the same thing, and choosing the wrong one for your project can mean redoing your beds in a year or two. Here's what you actually need to know.

What Is Bark?

Bark is exactly what it sounds like — shredded or chipped tree bark. It's a slow-decomposing material that breaks down gradually over time, usually 2–5 years depending on conditions.

Because it breaks down slowly, bark:

  • Stays in place longer and looks good for multiple seasons
  • Provides consistent weed suppression without frequent replacement
  • Works well around ornamental plants, shrubs, and trees
  • Protects soil temperature in winter and summer

Bark doesn't add significant nutrients to the soil as it breaks down — that's not what it's designed to do. It's a protective top layer, not a soil amendment.

What Is Mulch?

Technically, "mulch" is a broader category — it describes any material you lay over soil to protect it and retain moisture. Bark is a type of mulch. So are wood chips, straw, compost, and even gravel.

When people say "mulch" at a garden center, they usually mean an organic material that breaks down faster than bark — often a mix of wood chips or compost-based material. This type decomposes in 1–2 years and adds organic matter and nutrients to the soil as it breaks down.

Compost-based mulch:

  • Improves soil structure and microbial activity as it decomposes
  • Adds nutrients, especially nitrogen
  • Needs more frequent replacement
  • Works well in vegetable gardens where you want soil improvement

When to Use Bark

Bark is the better choice when:

  • You want a clean, finished look that lasts multiple seasons
  • You're mulching ornamental garden beds, around trees, or along pathways
  • Weed suppression is your primary goal
  • You don't want to remulch every year

In the Pacific Northwest, bark is especially practical for the areas around shrubs and trees that you set up once and don't want to maintain constantly through our rainy winters.

When to Use Compost-Based Mulch

Compost-based mulch is the better choice when:

  • You're mulching a vegetable garden and want the soil to improve
  • You have young plants that would benefit from added nutrients
  • You're building soil quality intentionally over multiple growing seasons
  • You're okay with replacing it annually

Pacific Northwest Considerations

Kitsap County's wet climate adds a few practical notes:

Crown rot risk: Don't pile bark or mulch directly against plant stems or tree trunks. In our wet climate, this creates conditions for crown rot. Keep a 2–3 inch gap around stems.

Drainage: Bark helps prevent soil compaction from heavy rain — it acts as a buffer, letting water infiltrate gradually instead of pounding and compacting the soil surface.

Timing: Best time to apply bark in the PNW is late fall (protects roots over winter) or early spring (suppresses weeds before growing season). Either works; both help.

What Harbor Soils Carries

We carry several bark and mulch options to match your project. Delivery throughout Gig Harbor, Port Orchard, Fox Island, Key Center, and surrounding Kitsap County — same-day available. No minimums.

Not sure which product fits your project? Call us at 253-857-5125. We'll point you in the right direction.