Common mistakes in growing seedlings include:
1) Not maintaining even temperatures between 70+ and 80+ degrees Fahrenheit during seed germination, emergence, and formation of first true leaves.
2) Not giving the seedlings full sunlight immediately upon emergence and all day thereafter – or if using grow-lights at least 16 hours of light each day.
3) Not feeding plants properly, which means a) having Pre-Plant Mix in the soil mix before planting seed, b) using only water until plants emerge from the soil, and c) watering with the Constant-Feed solution immediately upon emergence of your plants. The constant-feed solution is a mixture of 1 ounce (2 tablespoons) of Weekly Feed in 3 gallons of water.
If you are growing the seedlings inside your house, if it’s not warm, put a double fluorescent tube, with one cool and one warm, 1″ or closer to the plant leaves, and leave the lights on at least 16 hours per day. And the soil needs to be warm for the seeds to germinate. Buying an electric seed germination mat will improve your germination.