Make Your Own Organic Fertilizer: Complete Recipe and Method

Why DIY Fertilizer?

Control ingredients, save 50–70% vs. bagged organics, customize for your soil test, build soil biology—not just feed plants.

Base Mix (by volume)

• 4 parts seed meal (cottonseed, alfalfa, soybean) — nitrogen source
• 1/4 part agricultural lime (calcium)
• 1/4 part gypsum (calcium + sulfur) — or double lime
• 1/2 part dolomitic lime (calcium + magnesium)

Mix thoroughly. Stores dry indefinitely in sealed container.

Premium Additions (per batch)

• 1 part bone meal / rock phosphate / high-P guano — phosphorus
• 1/2–1 part kelp meal (or 1 part basalt dust) — micronutrients, growth hormones

Add at planting time; base mix can be used alone for maintenance.

Application

• Spring: broadcast 2–4 cups/100 sq ft, incorporate 4–6".
• Side-dress: 1/2 cup per plant monthly during growth.
• Container: 1 tbsp/gal potting mix at planting; 1 tsp/gal monthly.

Sourcing Ingredients

Feed stores (seed meal, lime), farm co-ops, online bulk suppliers (Peaceful Valley, BuildASoil, Amazon). Buy 50 lb bags for economy.

Soil Test First

Don't guess. $20–$30 lab test (Logan Labs, UMass, state extension) tells pH, CEC, nutrient levels. Adjust recipe accordingly.