What to Collect

Leaf mold is the dark, crumbly, humus-rich layer directly beneath the surface leaf litter in an undisturbed forest. It looks like worm castings — dark, aggregate-rich soil held together by fungal hyphae. You only need a handful (about 1 cup) per 5-gallon JMS batch.

Where to Dig

• Look for old-growth or mature trees — they've had decades to build fungal networks
• Collect under diverse tree species (oaks, bays, madrones, maples, beeches, hickories, redwoods) for maximum microbial diversity
• Seek north-facing slopes and creek-adjacent areas — higher moisture = more active biology
• Dig beneath fallen logs and under thick leaf litter where you can see white fungal mycelium and aggregate clumps
• Collect from multiple trees and microclimates per trip to diversify your culture

Legal Rules by Land Type (US)

• National Forest (USFS): Most permissive. Small quantities of leaves, plant material, and soil for personal, non-commercial use are generally allowed without a permit. Confirm with the local ranger district for specific rules.
• BLM Land: Explicitly allows "small amounts of plants, plant parts" for personal use. Excellent option in the western US.
• State Forests: Rules vary by state. Many allow personal-use collection of leaf litter — usually more permissive than State Parks. Check your state's DNR/DEC website.
• State Parks: Almost always prohibit collection without a scientific research permit. Not practical for casual collection anywhere in the US.
• National Parks: Prohibited — federal law prohibits removing any natural material.
• National Wildlife Refuges: Prohibited without a special use permit.
• Regional / County / Municipal Parks: Rules vary widely. Most technically prohibit removing natural materials but rarely enforce for small personal-use quantities. Collect discreetly.
• Private Land: Get written permission first. Undeveloped private timberland or a neighbor's wooded lot is often the easiest option.
• Roadside / Public ROW: Legal in most jurisdictions, but avoid — high contamination from vehicle emissions, tire particles, and de-icing salt.

Universal Contamination Red Flags

• Legacy mining areas: mercury (Almaden/New Idria in CA, Appalachia coal country), arsenic (old orchards), lead (old smelters)
• Roadside runoff: Collect at least 200ft from major roads and parking lots
• Conventional agriculture edges: Pesticide/herbicide drift is common at field margins
• Urban runoff: Skip parks in heavily industrial or urbanized areas with storm drains feeding into the forest
• Superfund and brownfield sites: Check the EPA Superfund locator before collecting from unfamiliar areas
• Recent wildfire burn scars: May have concentrated heavy metals and pyrogenic contaminants

Storage & Use

• Store in a sealed Ziploc or mason jar in a cool, dry place — stays viable for months
• Use ~1 cup leaf mold per 4-5 gallon JMS batch with boiled potato, sea salt, and dechlorinated water
• Best results at 70-75°F — bubbles form in 24-48 hours in warm weather, up to 6 days in cool temps
• Use JMS immediately once bubbles cover the full surface

How Scoring Works

Curated sites (★) — Hand-researched Bay Area sites with detailed scoring on tree species, moisture retention, known contamination risks, access ease, and site-specific collection restrictions.

Live search results — When you search a zip outside the curated area, LeafMoldSoilScout queries OpenStreetMap for nearby forested land and scores each result heuristically:

• Tree Diversity: Estimated from OSM ecosystem tags (mixed forest > monoculture)
• Moisture: Boosted for sites near water features and in humid climate zones
• Contamination: Reduced for sites near major roads, urban areas, or known industrial zones
• Access: Boosted for sites with named trails, parking, or public land designation
• Restrictions: Highest for National Forest / BLM, lowest for State/National Parks

Heuristic scores are a starting point — always verify with local knowledge and current regulations before collecting.