What organic fertilizer should I use on vegetables?

Finding the answer to “What organic fertilizer should I use on vegetables?” is not an easy task. Let’s start by defining “organic” as it applies to fertilizer.  An organic fertilizer is a soil amendment that comes from living creatures.  It can come from either plants or animals, and it may or may not be a good idea to use it on vegetables.

Commercially prepared fertilizers have three numbers that are important.  They are the percent of the three most important plant nutrients in the fertilizer (nitrogen, phosphorus and potassium).  Thus a 10-5-2 fertilizer would have 10% nitrogen, 5% phosphorus and 2% potassium. This is important information in finding the answer to “What organic fertilizer should I use on vegetables?” There are commercially prepared organic fertilizers available.  They are bagged and labeled the same as non-organic fertilizers, so you have to be careful to make sure you get certified organic fertilizer if you want to grow organic vegetables.  Any of the commercially prepared organic fertilizers can safely be used on vegetables.

There are other answers to “What organic fertilizer should I use on vegetables?” Compost is a home made organic fertilizer.  Compost is made from decaying vegetable matter, usually lawn clippings, vegetable waste and things like that.  As long as compost does not contain any animal matter, it is safe to use on vegetables at any time.  Compost can be made in a matter of weeks by turning and aerating it frequently and keeping it evenly damp.

Manure is another common organic fertilizer.  Manure can contain bacteria, including E. coli and other human pathogens.  In order to be used safely on vegetables, manure can be composted, which kills the microorganisms.  Manure should not be applied to vegetable crops less than 60 days before harvest.  It’s also important to thoroughly wash all root crops and crops that come in contact with the soil if it has been fertilized with manure.

Sewage sludge is an organic fertilizer, but it is NOT approved for use in organic gardening.  Sewage sludge is a byproduct of human sewage and, while it is legal to use as a commercial fertilizer, it may contain harmful bacteria.  Certified organic vegetables cannot be fertilized with sewage sludge.