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How to Fertilize Vegetable Seedlings

By Jenny Harrington ; Updated September 21, 2017
Proper feeding encourages healthy plant growth.

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.


Things You Will Need

  • Complete fertilizer
  • Watering can
  • Houseplant fertilizer


  • Seedlings often become yellow or weak in appearance when they require fertilization, according to North Carolina State University extension.


  • Do not over-fertilize the seedlings, as this can cause more damage than no fertilizer.

About the Author


Jenny Harrington has been a freelance writer since 2006. Her published articles have appeared in various print and online publications. Previously, she owned her own business, selling handmade items online, wholesale and at crafts fairs. Harrington's specialties include small business information, crafting, decorating and gardening.