Soil and Compost 

​

  🌱 Where to Get Organic Compost in Marin County

Compost & Landscape Supply Locations

1. West Marin Compost

• 📍 5575 Nicasio Valley Rd, Nicasio, CA 94946

• 📞 (415) 662-9849

• 🕐 Hours: Mon–Sat 7:00 AM – 3:00 PM (closed Sundays)

• 🪴 About: Offers locally produced compost and yard debris recycling. Great for soil amendment on farms or larger gardens. Organic blends available. (West Marin Compost)

• 💡 Discounts: Contact directly for bulk pricing and if they offer school/nonprofit rates (often negotiable on larger orders).

 

2. Marin Landscape Materials

• 📍 7596 Redwood Blvd, Novato, CA 94945

• 📞 (415) 897-1337

• 🕐 Hours: Mon–Sat 7:00 AM – 5:00 PM (closed Sundays)

• 🪴 About: Landscape supply store carrying a range of materials — including compost, mulch, soil amendments, and delivery services. (Marin Landscape Materials)

• 💡 Discounts: Call ahead to inquire about nonprofit or educational discounts for larger bulk purchases.

 

3. Martin Bros Supply LLC

• 📍 232 Shoreline Hwy, Mill Valley, CA 94941

• 📞 (415) 388-2025

• 🕐 Hours: Mon–Fri 7:30 AM – 3:30 PM, Sat 8:00 AM – 2:00 PM

• 🪴 About: Offers landscape soil, garden mixes, and compost blends.  At the moment  they cannot deliver materials. 

• 💡 Discounts: Call to check for nonprofit or school project discounts.

 

4. Cure Soil Compost, Inc.

• 📍 2845 Sir Francis Drake Blvd, Fairfax, CA 94930

• 📞 (Check website)

• 🕐 Hours: Generally daily 9:00 AM – 5:00 PM (confirm before visiting).

• 🪴 About: Garden center with quality soil and compost products suitable for organic gardening.

 

5. Green Jeans Garden Supply

• 📍 690 Redwood Hwy Frontage Rd, Mill Valley, CA 94941

• 📞 (415) 389-8333

• 🕐 Hours: Daily 10:00 AM – 6:00 PM (Sun 10:00 AM – 5:00 PM)

• 🪴 About: Garden supply store with organic soil amendments, compost, and gardening products.

 

🪣 Community / Seasonal Compost

✔️ Marin Water & City Events
Occasionally Marin Water and local cities host free compost giveaways where residents can pick up compost (bring your own shovel and container).

✔️ Marin Compost Giveaways by AIM / Zero Waste Marin
Local organizations sometimes host events distributing free compost (e.g., at Civic Center events). 

💡 Check local community calendars (Zero Waste Marin, Agricultural Institute of Marin) for current dates and sign up for Marin Garden Hub’s forum to keep updated on that. 

 

 

🎓 Discounts for Schools & Nonprofits

• Bulk & nonprofit pricing: Many suppliers offer volume discounts for large orders. Call ahead and mention your nonprofit, school garden, or educational purpose—suppliers will often accommodate with reduced pricing, delivery credits, or flexible pickup options.

• RethinkWaste (Shoreway Environmental Center): Provides free, high-quality compost for schools, gardens, and community groups, including free delivery options (up to 20 cubic yards).

• RecycleSmart: Offers a 50% off coupon code for backyard compost bins for residents, schools, and businesses in their service area.

• San Rafael / Zero Waste Marin: Provides up to $600 in free indoor compost bins for businesses/organizations that sign up for commercial composting. 

• Free Giveaways: Marin Water and Zero Waste Marin occasionally offer free compost to residents. 

 

🐛 How to Make Compost Onsite

Here are some effective techniques for composting on your school site, farm, or garden:

🌿 1. Basic Hot Composting

Goal: Quickly produce finished compost (weeks–months).
What you need:

• Carbon sources (browns): dry leaves, straw, wood chips.

• Nitrogen sources (greens): food scraps, grass clippings, manure.

• Air & moisture: keep moist (like a wrung-out sponge) and turn every 1–2 weeks.

Steps:

1. Build layers: alternating greens & browns.

2. Keep pile at least 3×3×3 feet.

3. Turn often to add oxygen and speed decomposition.

4. Do not add meat or dairy

Best for: School gardens, farms.

 

🪱 2. Cold Composting

Goal: Minimal labor; slower decomposition (~6–12 months).

• Add kitchen scraps and yard waste to a bin or pile.

• No regular turning required (but occasional mixing helps).

• Good if you have space and time.

• Do not add meat or dairy

 

🪵 3. Vermicomposting (Worm Composting)

Goal: High-quality compost worm castings — great for raised beds.
What you need:

• A worm bin (indoor/outdoor).

• Red worms (red wigglers).

• Bedding: shredded paper, cardboard, leaves.

• Kitchen scraps (no dairy/meat).

How:

• Add food scraps to the bin; worms turn it into rich castings.

• Harvest nutrient-dense compost every few months.

 

📦 4. Trench or Pit Composting

Technique: Dig a trench or pit in your garden bed, add organic scraps, and cover with soil. No diary or meat products 

• Breaks down over several months right in place.

• Simple for school gardens where turning piles isn’t practical.

 

📌 Composting Tips

✅ Keep a good balance of carbon and nitrogen — a 2:1 ratio of browns to greens is ideal.
✅ Chop or shred materials — smaller pieces decompose faster.
✅ Avoid meats, oils, and dairy in backyard piles (this attracts pests).
✅ Water regularly — material should be damp but not soggy.

The ideal compost temperature is 

130°F to 150°F (54–66°C) for hot composting, which sanitizes the pile by killing pathogens and weed seeds. For faster decomposition, maintain a range of 90°F to 140°F (32–60°C). If the pile drops below 120°F, it may need to be turned or watered to boost activity.

Discounts for Schools & Nonprofits

• RethinkWaste (Shoreway Environmental Center): Provides free, high-quality compost for schools, gardens, and community groups, including free delivery options (up to 20 cubic yards).

• RecycleSmart: Offers a 50% off coupon code for backyard compost bins for residents, schools, and businesses in their service area.

• San Rafael / Zero Waste Marin: Provides up to $600 in free indoor compost bins for businesses/organizations that sign up for commercial composting. 

• Free Giveaways: Marin Water and Zero Waste Marin occasionally offer free compost to residents. 

​

​

🪱Red wiggler worms for composting in Marin County can be purchased from specialty online vendors like Uncle Jim’s Worm Farm or NaturesGoodGuys, which ship directly to your door. Locally, check with nurseries or local garden shops in Marin. 

​

Local Options (Best to Call Ahead):

Local Bait & Tackle Shops: Sometimes stock "red worms," but ensure they are Eisenia fetida (Red Wigglers)

• Fish Story in Novato

• Loch Lomond Live Bait House in San Rafael

Other close by options:

Berkeley Horticultural Nursery

East Bay Nursery

Online Options (Reliable Shipping):

• Nature's Good Guys: Offers live red worms.

• Uncle Jim's Worm Farm: Specializes in composting worms with a live delivery guarantee.

• Gardener's Supply Company: Sells red wigglers and composting kits. 

​

• How and where to get your soil tested 

There are many soil testing labs but Sanzuma always uses the one below. Please click on the link and follow their directions. 

https://allabswest.wordpress.com/soil-analysis/

​

🌿 What cover crops grow well in Marin County’s climate?

For Marin County gardens, the best winter cover crops include blends of 

vetch, bell beans, and field peas for nitrogen fixation, combined with bell beans, barley, or rye to build soil organic matter and prevent erosion. Mustard and radishes are excellent for breaking up compacted clay soils and suppressing weeds.

 

Purchase at:

Harmony Farm Supply in Sebastopol 

If you sign up ahead of arriving they offer school discounts. They also have a store in Petaluma, not sure if they carry the seeds in bulk there, 

Address: 3244 Gravenstein Hwy N, Sebastopol, CA 95472

Monday - Saturday 7:30 AM–5 PM

Sunday 9:00 AM - 5:00PM

Phone: (707) 823-9125

Sloat Nursery and Ace Hardware 

Sold in seed packets