Growing your vegetables from seed is less expensive than purchasing seedlings. Vegetables are usually planted in sterile soil, which prevents disease from killing the young plants. Sterile soil usually has no nutrients in it, so additional fertilization is necessary if the seedlings are to survive. Newly emerged seedlings use the nutrients in the seed to grow, but within a few days these nutrients are gone. Seedlings require regular feeding once they produce their second set of leaves.
Nutrient Solution Method
Mix 2 cups of a complete fertilizer, such as 10-20-10 analysis, with 1 gallon of warm water. Place the mixture into a watering can or other container.
Water the vegetable seedlings with the fertilizer solution when the soil surface begins to dry out. Water until the excess moisture begins draining from the bottom of the pots.
Water with clear tap water once a week. Plain water flushes out any excess fertilizer salts from the soil. Too much salt can damage seedlings.
Standard Fertilizer Method
Dilute a 20-20-20 analysis houseplant fertilizer to half strength. Follow package instructions for mixing, using only half the fertilizer ratio recommended on the package. In general, a mixture of 1 to 2 tsp. of fertilizer per 1 gallon of water is a sufficient application ratio.
Fertilize the seedlings with the dilute houseplant fertilizer every two weeks. Start the first fertilization when the second set of leaves emerge, or one week after germination, whichever occurs first.
Water with plain water between each fertilization application. Water until the excess moisture drains from the bottom of the pot, ensuring the excess fertilizer salts are washed from the soil.