Organic Nitrogen Fertilizers
Organic nitrogen fertilizers for gardens, vegetables, lawns & raised beds
Whether you're feeding a vegetable garden, greening up a lawn, building raised beds, or maintaining established flower borders — organic nitrogen sources release gradually as soil microbes break down the material, feeding plants steadily while building the soil biology that makes future seasons more productive. Shop fast-acting and slow-release organic nitrogen fertilizers for greener growth and healthier soil.
Selected products in this collection are OMRI listed or approved for certified organic production — check individual product pages for current certification details. All are derived from natural organic materials and third-party tested for heavy metals.
Compare organic nitrogen sources
The right product depends on how urgently your plants need nitrogen and how long you need it to last. For best results, apply when soil temperature is consistently above 50°F.
| Product | NPK | Nitrogen % | Release Speed | Best Use Case |
|---|---|---|---|---|
| Blood Meal | 13-0-0 | 13% N | Fast — starts within 1–2 weeks, completes over 6–8 weeks | Correct nitrogen deficiency quickly mid-season; compost activation; heavy-feeding vegetables and corn. Generally unnecessary for legumes unless a soil test shows deficiency. |
| Feather Meal | 12-0-0 | 12% N | Slow — 3–4 months | Long-season crops (tomatoes, corn, brassicas); one pre-season application can feed through harvest without reapplication |
| Alfalfa Meal | 2.5-0-2.5 | 2.5% N | Medium — 4–8 weeks | Roses, vegetable beds, compost activation; gentle N + K with natural triacontanol, valued by gardeners for supporting vigorous growth |
| Crustacean Meal | 4-0-0 | 4% N | Slow — 3–4 months | Soil biology boost; one of few amendments that delivers both nitrogen (4%) and calcium (~12%) without raising pH; adds chitin to feed beneficial microbes |
Which organic nitrogen source should you choose?
Plants are visibly nitrogen-deficient right now
→ Blood Meal 13-0-0. Among the fastest-releasing organic nitrogen sources — begins releasing within 1–2 weeks in warm soil. Work into moist soil and water in immediately.
Pre-season application for long-season crops
→ Feather Meal 12-0-0. Releases over 3–4 months — one application before planting can feed corn, tomatoes, and brassicas through harvest without reapplication.
Roses, established beds, or compost piles
→ Alfalfa Meal 2.5-0-2.5. Gentle N + K with natural triacontanol. Accelerates compost decomposition and supports soil biology without risk of burning.
Need nitrogen and calcium without raising soil pH
→ Crustacean Meal 4-0-0. Delivers nitrogen, calcium, and chitin in one amendment — without the pH-raising effect of lime-based calcium sources.
Frequently asked questions
Can I mix multiple organic nitrogen sources together?
Yes — combining sources is common practice and often the right approach. A popular combination is Feather Meal at planting for season-long slow release, with Blood Meal available for mid-season side-dressing if a fast nitrogen boost is needed. These materials are commonly mixed together successfully. Account for total nitrogen from all sources to avoid over-application.
Why do organic gardeners choose organic nitrogen over synthetic sources?
Organic nitrogen sources release more slowly than synthetic fertilizers, which reduces burn risk and more closely matches the pace at which plants actually feed. As they break down, they also feed beneficial soil microbes, add organic matter, and improve soil structure over time — benefits that synthetic nitrogen sources don't provide. For certified organic production, only organic-approved sources are permitted. Many gardeners use organic nitrogen as their foundation and supplement with water-soluble fertilizers only when fast correction is needed.
Why is Blood Meal generally unnecessary for legumes?
Legumes (beans, peas, soybeans, clover) fix their own atmospheric nitrogen through root bacteria (Rhizobia). Adding nitrogen fertilizer disrupts this symbiosis — the plant reduces or stops nitrogen fixation when soil nitrogen is already available, and the nitrogen-fixing bacteria population declines. Unless a soil test shows genuine nitrogen deficiency in a legume crop, additional nitrogen fertilizer is generally unnecessary and counterproductive.
Are these products approved for certified organic production?
Selected products in this collection are OMRI listed or approved for certified organic production — check individual product pages for current certification details. All products are derived from natural organic materials and third-party tested for heavy metals. Results are available on our Heavy Metal Analysis page.
For more on feeding vegetables and building soil fertility organically: