| They may need nitrogen such as fish emulsion or manure tea... most commercial potting soils are 'sterile' meaning they lack nutrients and microorganisms (unless it's one of the soils w/ included chemical fertilizer). Manure tea is great w/ sterile mixes as it provides microorganisms and helps prevent problems w/ 'damping off' fungus (sm plants die/fall over at base). Damping off doesn't tend to plague organic seed mixes as it's primarily an 'opportunistic' organism (which means it colonizes soils lacking a healthy community of other microorg's). |
Here is a link that might be useful: Vegetable Seed Saver's Handbook (free)