"Should I get bark or mulch?" is one of the most common questions we hear at Harbor Soils. The short answer: bark is mulch. But what most people really want to know is which type of ground cover is right for their yard.
Here's the breakdown: what each type actually is, how they compare, and which one makes sense for your project in western Washington.
Quick answer: what's the difference between bark and mulch?
Bark is a type of mulch. Mulch is the broad category for any material spread over soil to retain moisture, suppress weeds, regulate temperature, and prevent erosion. It includes bark, wood chips, compost, straw, and rock. In the Pacific Northwest, most bark mulch is made from Douglas fir and hemlock processed at local sawmills. At Harbor Soils in Gig Harbor, fine bark is $35.99/yd, medium bark is $36.99/yd, dark fine bark is $38.99/yd, and small nugget bark is $54.99/yd. The practical rule: all bark is mulch, but not all mulch is bark.
Bark vs Mulch: The Quick Answer
Mulch is the broad category. It's any material spread over soil to retain moisture, suppress weeds, regulate temperature, and prevent erosion. It includes bark, wood chips, compost, straw, rubber, and rock.
Bark is a specific type of organic mulch made from the outer layer of trees. Per the Mulch and Soil Council, bark products contain 85% or more actual bark (not interior wood). In the Pacific Northwest, most bark comes from Douglas fir and hemlock processed at local sawmills.
Think of it this way: all bark is mulch, but not all mulch is bark. Just like all squares are rectangles.
Types of Bark Mulch
Bark comes in several grades, each suited to different jobs:
| Type | Size | Best For | Lifespan |
|---|---|---|---|
| Fine bark (5/8" minus) | Small, uniform pieces | Front yards, formal beds, around flowers | 12-18 months |
| Medium bark (1-1/2" minus) | The workhorse grade | General landscaping, slopes, foundation beds | 18-24 months |
| Dark bark | Varies | Modern landscapes, commercial properties | 18-24 months |
| Bark nuggets | Large chunks | Around trees and large shrubs | 2-4 years |
| Cedar bark | Varies | Areas where some insect deterrence is helpful | 3+ years |
In Kitsap and Pierce counties, medium bark is by far the most popular choice. It balances appearance, cost, and longevity, and it holds well on slopes during our heavy rains.
Other Types of Mulch (Non-Bark)
If bark isn't the right fit, here are the alternatives:
Wood Chips
Made from branches and trunks, including interior wood, not just bark. More rustic-looking and often available free from local arborists. One caution: fresh wood chips can temporarily leach nitrogen from soil as they decompose. Use aged chips in planting beds, or reserve fresh chips for pathways only.
Compost
Decomposed organic matter that's nutrient-rich and great for soil improvement. Breaks down fast (needs refreshing every few months), so it's not ideal as a standalone weed barrier. Best for vegetable gardens and flower beds where you want to feed the soil.
Straw
Lightweight and affordable. Best for newly seeded lawns, vegetable gardens, and strawberry beds. Applied 6–8 inches deep. Important: use straw, not hay. Hay contains weed seeds.
Rock and Gravel
Essentially permanent (10+ years). No decomposition, no annual replacement. But rock doesn't retain moisture, can overheat soil in summer, and is extremely difficult to remove once installed. Best for driveways, drainage areas, and xeriscaping.
Rubber Mulch
Made from recycled tires. Long-lasting but can emit a strong odor in heat. Studies have shown potential toxin leaching, and it doesn't improve soil health. Mainly used for playgrounds and high-traffic commercial areas.
Bark vs Mulch: Side-by-Side Comparison
| Factor | Bark | Wood Chips | Compost | Rock/Gravel |
|---|---|---|---|---|
| Cost (per cubic yard) | $30–$65 | $30–$50 (often free) | $25–$50 | $50–$180 |
| Lifespan | 1–4 years | 1–3 years | 2–6 months | 10+ years |
| Weed suppression | Excellent | Good | Fair | Good (initially) |
| Moisture retention | Excellent | Good | Excellent | Poor |
| Soil improvement | Moderate (slow) | Moderate (slow) | Excellent | None |
| Appearance | Clean, uniform | Rustic, uneven | Dark, earthy | Clean, permanent |
| PNW rain performance | Holds well (medium grade) | Holds well | Can wash away | Stays put |
| Best for | Landscape beds, slopes | Paths, informal areas | Veggie gardens | Drainage, walkways |
Which Mulch Is Right for Your Project?
Here's a quick decision guide based on what you're trying to do:
Flower beds and foundation plantings: Fine or medium bark. Clean look, good weed control, lasts 1-2 seasons.
Vegetable garden: Compost or straw. You want to feed the soil, not just cover it.
Around trees and shrubs: Medium bark or bark nuggets. Apply 2-3 inches deep in a ring, but keep bark 3-4 inches away from the trunk. Piling mulch against the trunk ("mulch volcano") causes rot.
Pathways and informal areas: Wood chips or 5/8 minus gravel. Both are durable underfoot and low-maintenance.
Slopes: Medium bark. It interlocks and holds better than nuggets or fine bark in heavy rain.
Drainage areas and driveways: Crushed rock or gravel. You need something permanent that won't decompose or float away.
Acid-loving plants (rhododendrons, blueberries, azaleas): Bark mulch or pine needles. Both are naturally slightly acidic, which these PNW favorites love.
How Much Do You Need?
For most mulch applications, you want 2–3 inches of depth. Here's the coverage math:
- 1 cubic yard covers about 162 sq ft at 2 inches deep, or 108 sq ft at 3 inches deep
- A typical front yard bed (200 sq ft) needs about 1.5–2 cubic yards
- A full landscape refresh for a standard home lot: 3–6 cubic yards
Not sure how much you need? Use our mulch calculator or cubic yard calculator to figure it out.
Common Misconceptions
"Fresh wood chips are fine around plants"
Not in planting beds. Fresh, uncomposted wood chips can temporarily rob nitrogen from the top layer of soil as microbes work to break them down. Use aged chips in gardens, or save fresh chips for pathways where they won't contact plant roots.
"Mulch attracts termites"
Mulch doesn't attract termites, but it does create moist conditions they like. The solution isn't to skip mulch. Just keep it a few inches away from your foundation and any wooden structures.
"More mulch is always better"
Over-mulching suffocates roots and creates rodent habitat. Stick to 2–3 inches. Never pile mulch against tree trunks or plant stems.
"Bark mulch makes soil too acidic"
When applied as a surface layer (not tilled in), bark's effect on soil pH is minimal and temporary. It's fine for the vast majority of plants.
"Rock mulch is maintenance-free"
Weeds eventually grow between rocks. Leaves and debris accumulate. And once you install rock, removing it is a major project. Rock is low-maintenance, not no-maintenance.
What We Carry
At Harbor Soils, we carry a full range of bark and mulch products, all sourced from Pacific Northwest mills:
- Fine Bark
- Medium Bark
- Dark Fine Bark
- Small Nugget Bark
- Double Grind Mulch (wood chips)
- Harbor Mulch
- Hog Fuel
We deliver same-day across Gig Harbor, Port Orchard, Bremerton, Silverdale, Poulsbo, and greater Kitsap County. No minimum order. Browse all bark and mulch or call 253-857-5125 to order.
Frequently Asked Questions
Is bark mulch safe for dogs and other pets?
Standard fir, hemlock, and cedar bark mulch is generally safe for dogs. The one to avoid is cocoa mulch, which contains theobromine (the same compound that makes chocolate toxic to dogs). For households with pets, plain bark dust or Fine Bark from a local supplier is the safe default.
When in spring should I apply bark in Western Washington?
Mid-March through late April is the sweet spot. You want bark down before weed seeds germinate but after the worst of the winter rain has passed so the surface stays put. In Kitsap County, aim to finish before the end of April. After that you'll be fighting established weeds and chasing the start of the dry season.
Should I remove old bark before applying a fresh layer?
Usually not. Top up over the existing bark unless the old layer is more than 4 inches deep total or has matted into a hard crust. The bottom layers are already decomposing and feeding your soil. Total depth after refresh should be 2 to 3 inches.
Do I need landscape fabric under bark mulch?
For planting beds, no. Landscape fabric restricts the air and water exchange that mulch is supposed to support and degrades soil microbes over time (per WSU Extension research). Reserve fabric for hardscape applications like under gravel paths or decorative rock. See our landscape fabric vs mulch comparison for the full case.
How long does fine bark actually last in Kitsap's wet climate?
Plan on annual refresh for fine bark in high-visibility front yard beds. Our wet winters break it down faster than most regions; the 18-month industry average is closer to 12 in our climate. Medium bark stretches to 2 years, coarse and nugget bark to 3 or more.
Will bark mulch attract slugs in our wet climate?
Bark itself doesn't attract slugs, but any mulch creates the moist undersurface they like to hide in. Two practical mitigations: pull bark a few inches back from plant stems where slug damage starts, and consider a thin layer of cedar bark in problem areas (cedar's natural compounds are mildly slug-deterrent).