Weeds are every gardener's nemesis. Two popular weed-control methods compete for your attention: landscape fabric and mulch.
Both work. Both have pros and cons. But for most gardens, the right answer is clearer than you might think, and it has more to do with your soil than your weeds.
This guide covers how each works, what they cost over five years, what they do to your soil, and exactly which to use for driveways, flower beds, vegetable gardens, and tree borders.
Quick Answer: Which One Should You Use?
- Vegetable gardens, flower beds, tree borders: Mulch alone. No fabric.
- Driveways, gravel paths, decorative rock areas: Woven fabric under mulch or stone.
- Anywhere you want soil to improve over time: Mulch only.
- Anywhere soil quality doesn't matter (hardscape): Fabric is fine.
The short version: fabric is a hardscape product, not a garden product. Use it where you don't want anything to grow ever. Use mulch everywhere else.
How Landscape Fabric Works
Landscape fabric (also called weed barrier or landscape cloth) is a synthetic mesh material laid over soil to physically block weeds.
How it suppresses weeds:
- Acts as a physical barrier between soil and air
- Prevents wind-blown seeds from reaching soil
- Blocks light to existing weeds underneath
Two main types:
- Woven fabric. More durable, breathable, lasts 3 to 5 years for residential grades, 5 to 10 years for UV-stabilized professional grades.
- Non-woven fabric. Cheaper, less durable, compacts and breaks down in 1 to 3 years.
Installation basics: Lay fabric directly over soil, pin down corners and seams, cut X-shaped slits for plants, then top with a thin layer of mulch or rock to protect the fabric from UV.
How Mulch Works
Mulch is organic material (bark, wood chips, compost, or straw) spread over soil. Harbor Soils carries several options including Fine Bark, Dark Medium Bark, Double Grind Mulch, and Harbor Mulch.
How it suppresses weeds:
- Creates a 2 to 3 inch light-blocking layer
- Physically buries small weed seeds too deep to germinate
- Smothers shallow-rooted weeds underneath
- Creates a competitive surface that disadvantages new seedlings
Mulch types:
- Bark dust and bark chips. Long-lasting (1 to 3 years depending on size), attractive, good weed suppression. See our complete guide to mulch types.
- Wood chips. Budget-friendly, settle faster, good for tree borders.
- Compost mulch. Breaks down in a year, enriches soil, excellent weed suppression in vegetable gardens. Try Fine Compost or Mushroom Compost.
- Straw. Great for vegetable beds, breaks down each season.
Installation basics: Spread 2 to 3 inches over soil, keep 4 to 6 inches clear of plant stems and tree trunks, top up annually as it breaks down.
Head-to-Head Comparison
| Factor | Landscape Fabric | Mulch |
|---|---|---|
| Initial Cost | $0.30 to $1.20 / sq ft | $35 to $55 / cubic yard (covers 108 sq ft at 3") |
| Weed Prevention | Excellent at first, declines as fabric clogs and tears | Very good, consistent if refreshed |
| Longevity | 1 to 5 years (woven beats non-woven) | 1 to 3 years per application, indefinite with refreshes |
| Impact on Soil | Restricts air, water, organic matter | Improves soil and feeds microbes |
| Appearance | Visible at edges, looks industrial | Natural, attractive, matches landscape |
| Maintenance | Replace when degraded (messy) | Top-dress annually (easy) |
| Cost over 5 Years | ~$300 to $500 per 100 sq ft | ~$200 to $300 per 100 sq ft |
What WSU Research Says About Landscape Fabric
This is where the conventional "fabric stops weeds, just install it and forget it" advice falls apart.
Research published by Dr. Linda Chalker-Scott, the WSU Extension Urban Horticulture Specialist, shows that landscape fabric reduces carbon dioxide movement between soil and atmosphere by roughly 1,000 times more than wood chip mulches. Oxygen exchange is similarly restricted. Both effects damage soil microbes, roots, and soil-dwelling animals beneath the fabric.
Even fabric with holes loses permeability quickly: pores clog with fine soil particles and decomposing mulch within a season or two. The result is compacted soil, dry conditions even when it's raining, and the slow decline of the soil food web that healthy plants depend on.
The Illinois Extension and University of Maryland Extension reach similar conclusions: landscape fabric is poorly suited to garden beds because it prevents the natural cycling of organic matter into the soil.
For Kitsap County and the rest of the wet PNW, this matters even more. Our soil-microbe activity is already moisture-limited in summer; cutting off air and water exchange compounds the problem.
Bottom line: Fabric controls weeds in the short term. Mulch controls weeds and builds soil. For any planting bed, that's a one-sided trade.
Long-Term Cost Comparison (100 sq ft over 5 years)
Landscape Fabric Path
- Year 1: Install woven fabric ($60 to $100) plus thin mulch top layer ($30) = $90 to $130
- Years 2 to 4: Top up mulch layer annually ($30/year) = $90
- Year 5: Replace fabric (if non-woven failed sooner) plus mulch = $90 to $130
- 5-year total: roughly $270 to $350
Add labor for fabric removal/replacement (it's messy work) and the cost climbs further.
Mulch-Only Path
- Year 1: Initial 3" application = ~1 yard at $45 + delivery = $60 to $90
- Years 2 to 5: Top up 1 to 2" annually = ~0.6 yards at $30 + delivery × 4 years = $160
- 5-year total: roughly $220 to $250
Verdict: Mulch is cheaper over five years and leaves you with better soil at the end of it.
Impact on Soil Health
Landscape Fabric
Pros:
- Doesn't introduce chemicals to soil
- Holds in some moisture short-term
Cons:
- Severely restricts gas exchange (per WSU research)
- Blocks rainwater from reaching soil evenly
- Prevents new organic matter from cycling in
- Clogs over time, creating a hardpan layer
- Soil microbes decline; structure degrades
Mulch
Pros:
- Adds organic matter as it decomposes
- Improves soil structure and water-holding capacity year over year
- Feeds beneficial microbes and earthworms
- Moderates soil temperature in summer and winter
- Soil gets better the longer you use mulch
Cons:
- Decomposes, so needs annual refresh
- Can cause stem rot if piled against plant crowns ("volcano mulching")
- Some types (fresh wood chips) tie up nitrogen short-term
Verdict: Mulch wins on soil health. Fabric degrades soil over time. There's no contest here.
Which to Use: Real Scenarios
Vegetable Gardens
Use: Mulch only. No fabric, ever.
Why: Vegetables demand active soil biology and consistent organic-matter input. Fabric prevents both. Vegetables also need easy water and air infiltration to roots.
Best mulch: Compost (Fine Compost or Mushroom Compost), straw, or aged wood chips on pathways.
Cost: $40 to $60 per year for 100 sq ft.
Ornamental Flower Beds
Use: Mulch only.
Why: Flowers benefit from soil that improves over time, and bark mulch looks better than fabric edges showing through. The 5-year cost is lower too.
Best mulch: Fine Bark, Dark Fine Bark, or Double Grind Mulch. See our best mulch for flower beds guide.
Cost: $50 to $80 per year for 100 sq ft.
Driveways and Gravel Paths
Use: Woven fabric under 3/4" Minus, 5/8" Minus, or other gravel.
Why: No soil health concern (you don't want anything growing here). Fabric prevents gravel from sinking into soil and stops weeds from pushing up through gaps.
Best fabric: Heavy-duty woven, ideally professional-grade (200 GSM or higher).
Tree and Shrub Borders
Use: Mulch only. Keep 4 to 6 inches clear of trunks.
Why: Trees thrive on the slow drip of organic matter that mulch delivers. Fabric around trees creates the same gas-exchange problems as in beds, with worse consequences for established root systems.
Best mulch: Bark chips, Dark Medium Bark, or aged wood chips. See our guide on mulching around trees.
Rock and Decorative Stone Areas
Use: Woven fabric under decorative rock or river rock.
Why: Stops rocks from migrating into soil and prevents weed pressure. Soil health under rock features isn't a goal.
Best products: Pair fabric with Rainbow 1 1/2" Drain Rock or any of our rockery rocks.
Our Recommendation
For most gardens: skip the fabric. Use mulch.
- Soil improves yearly with mulch. Fabric does the opposite.
- Mulch is cheaper over 5 years. Fabric replacement adds up.
- Mulch looks better. Fabric edges and tears show through eventually.
- Mulch is easier to maintain. Top-dress in spring and you're done.
- Mulch supports plants. Fabric stresses them.
The exception: Use woven fabric under driveways, gravel paths, and rock features where weed control matters but soil health doesn't.
Frequently Asked Questions
Can I use both fabric and mulch together?
Only on hardscape (driveways, gravel paths, decorative rock). On planting beds, fabric blocks the very thing mulch is supposed to do. Stacking them defeats the purpose.
How long does landscape fabric actually last?
Woven residential grade: 3 to 5 years. Non-woven: 1 to 3 years. Professional UV-stabilized woven: 5 to 10+ years. UV exposure, foot traffic, and root pressure all shorten lifespan.
Does mulch attract termites?
Termites don't eat mulch and aren't drawn to it specifically. They will travel through mulch to reach wood structures, so keep any wood-based mulch 6 inches away from siding and foundations.
Can I plant through landscape fabric?
Yes, with X-shaped slits. But understand that the fabric is still restricting air and water around the root zone, so the plant will grow more slowly and need extra attention. Better to skip the fabric for planted areas.
What if I already have fabric installed and weeds are still pushing through?
That's typical after 2 to 3 years. Pulled weeds can be replaced by ones rooting on top of the fabric in the mulch layer above. The fabric is no longer doing useful work. Pull it out, top-dress with fresh mulch, and you'll see better results within a season.
Is dyed mulch safe?
Most modern dyes are iron-oxide or carbon-based and considered safe. Avoid dyed mulch sourced from recycled wood (could include treated lumber). Stick with natural-color bark from a known supplier for vegetable beds.
How often do I need to refresh mulch?
Every spring. Add 1 to 2 inches to bring depth back to 3 inches. Fine bark in the wet PNW typically needs annual refresh. Coarse bark or wood chips can stretch to every 2 to 3 years.
The Bottom Line
Landscape fabric belongs on hardscape: driveways, gravel paths, decorative rock features. It's a barrier product designed to keep things from coming up.
Mulch belongs on every planting bed in your landscape. It controls weeds and builds soil, which fabric cannot do.
If you're choosing for a vegetable garden, flower bed, or tree border, the answer is mulch. WSU research and 5-year cost math both point the same direction.
Order Bulk Mulch from Harbor Soils
Harbor Soils delivers fine bark, medium bark, double grind mulch, and compost throughout Gig Harbor and Kitsap County. Same day. No minimums.
- Browse our full bark collection
- Browse our compost selection
- Visit harborsoils.com to order or get a quote