Why are my indoor seedlings yellow-green? Help!

Question:

The seedlings that I have started indoors are yellow-green in color. What should I do?

Answer:

The yellow-green color is likely due to a nutrient deficiency. Nitrogen and phosphorus deficiencies sometimes occur when flower and vegetable seedlings are started indoors. Symptoms of a nitrogen deficiency include yellow-green foliage and stunted plant growth. Phosphorus-deficient plants have purplish leaves. Applying a dilute fertilizer solution once every two weeks should help supply adequate nutrients to the seedlings.