Those ingredients are perfect for a DIY seed starting mix, and they serve as both a growing medium and a mild fertilizer. Here's a breakdown of what you're looking at:
What it does: Lightweight, holds water well, and provides good aeration.
Replaces: Peat moss (eco-friendlier).
Nutrients? Minimal — mostly structure and moisture retention.
What it does: Improves moisture retention and aeration.
Nutrients? Contains trace minerals, but not a major nutrient source.
Common in: Most seed starting mixes — it helps seeds stay moist and oxygenated.
What it does: Provides a mild, balanced organic fertilizer rich in microbes.
NPK (approx.): ~1-0-0 to 1-0-1, gentle enough for seedlings.
Bonus: Adds beneficial bacteria and fungi that promote strong roots.
2 parts Coco Coir or Peat Moss
1 part vermiculite
1 part worm castings
You can adjust based on what you need:
More vermiculite if your area is hot and dry.
More coco coir if your mix seems too wet or heavy.
Light and fluffy — seeds sprout easily.
Moisture-retaining but not soggy.
Worm castings feed seedlings gently, so you don’t need extra fertilizer right away.
A dash of kelp meal (for micronutrients)
A sprinkle of mycorrhizal inoculant (for root health)
Compost tea or diluted fish emulsion after seedlings grow true leaves
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