Harbor Soils delivers bulk compost, mushroom compost, fish compost, and premium garden soil blends throughout Kitsap County, including Gig Harbor, Port Orchard, Bremerton, Silverdale, Poulsbo, and Bainbridge Island. From soil amendment for established beds to fresh fill for raised vegetable gardens, we deliver by the cubic yard with no minimums, direct from our yard at 11612 WA-302.
What is compost, and why does it matter?
Compost is fully decomposed organic matter, stable enough to stop heating and ready to feed plants without burning roots. Quality compost transforms heavy clay (common in Kitsap glacial soils) into a friable, water-retaining growing medium, while also fertilizing existing beds. Unlike fertilizer, compost works slowly and continuously: it improves soil structure, feeds the soil microbiome, and increases water-holding capacity. The result is healthier plants that need less watering and fewer chemical inputs. Curious about the difference between compost and peat moss as soil amendments? Read our peat moss vs compost guide.
Compost types we deliver
- Mushroom compost: rich, dark organic amendment that improves clay soil, water retention, and fertility. Made from spent mushroom-growing substrate (typically straw, gypsum, and manure). Best mixed into existing soil, not used as a standalone planting medium.
- Fish compost: nutrient-dense compost made with fish waste byproducts. Higher nitrogen and phosphorus than typical compost, excellent for vegetable beds and high-feeder crops.
- Tagro: City of Tacoma's biosolid-based soil amendment. EPA Class A material, nutrient-rich, ideal for topdressing lawns and enriching planting beds.
- Organic compost: balanced general-purpose compost for soil amending and bed refreshing.
- Garden Mix blends: premium ready-to-plant raised-bed mixes built on a compost base (mushroom or fish), combined with screened topsoil and sand.
- Prep (Soil Prep Mix): pre-blended preparation mix for new bed setup.
How to use compost in Kitsap soil
For existing beds, top-dress with 1 to 2 inches of compost in early spring or late fall. Don't till it in; let the soil microbes draw it down naturally. For new raised beds, fill with a Garden Mix blend rather than pure compost (pure compost is too rich and dense for direct planting). For clay soil amendment, mix 2 to 3 inches of compost into the top 6 to 8 inches of existing soil. For lawn topdressing, spread 1/4 to 1/2 inch over established grass after aeration. Our raised-bed soil guide for Western Washington covers the recipe in more detail.
How much compost do I need?
Compost is sold by the cubic yard. One yard covers about 100 square feet at 3 inches deep. For top-dressing existing beds, plan on 1 yard per 200 to 300 square feet. For amending soil during new bed prep, plan on 1 yard per 100 square feet at 4 inches deep mixed into existing soil. Use our landscape material calculator for project-specific yardage.
Building or refreshing planting beds?
Pair compost with topsoil and garden soil blends for new bed setup, and bark mulch as a top layer once your plants are in. All three deliver together on the same order.
Compost delivery in Kitsap County
We deliver bulk compost throughout the Kitsap Peninsula, including Port Orchard, Gig Harbor, Bremerton, Silverdale, Poulsbo, Kingston, and Bainbridge Island. Same-day delivery for most orders placed before noon. Call 253-857-5125 or order online to schedule.