Oregon State University Extension Service


Do I need cow manure and chemical fertilizers to grow plants well?

I am planning to mix top soil and cow manure with 1:1 ratio and use for growing vegetables, flowers, plants in a plastic container/pot. I will be using fertilizers for the plants with NPK 16-12-12 as per the recommended usage in the pack. Will the plants grow well?

The answer is "maybe." Here are some factors to consider:

  • Is the cow manure is well aged (composted) or is it new? It's important that it be aged for it to work with your plants, as explained in this article: Turn manure into compost for your garden
  • When properly used, manure eliminates the need to apply chemical fertilizer, since they both supply, the three major nutrients needed by plants: nitrogen, phosphorus and potassium. Here is another article specifically devoted to fertilizers: Fertilizing Your Garden

Finally, you might find the information in this OSU publication helpful: Growing Your Own (EM9027). It covers everything you need to know about vegetable gardening in the PNW. Good luck!


Source URL: https://extension.oregonstate.edu/ask-extension/featured/do-i-need-cow-manure-chemical-fertilizers-grow-plants-well