Is Fall Fertilization Really Necessary?

The short answer is, “it depends.” If you have had to fertilize each spring, the answer is, “yes.”It is important to first understand the role of fertilizer in gardening. At the risk of being redundant, I’ll explain once again that fertilizer does not feed plants. Plants make their own food through photosynthesis. However, the process requires certain naturally occurring elements to complete the reaction. While these nutrients are found in good topsoil, most of our topsoil has been scraped away, leaving only the subsoil. That means we have to replace those nutrients. That is done with fertilizer. We include beneficial fungi and bacteria, called myccorhyzae, to extend the roots’ ability to find water and oxygen.Fertilization can be compared to you and me taking vitamin supplements. They replenish the nutrients deficient in our diet.If you fertilize every spring because your soil needs it, you should fertilize in the fall because your plants will have used up the nutrients that you replenished in spring. In other words, soil does not make more nutrients. Deficient nutrients need to be replaced on a regular basis.Even after deciduous plants have lost their leaves, the roots continue to function until the ground freezes. Fall fertilization provides plants with the nutrients they need to continue making food as long as possible. This means having plenty of energy stored to sustain them through the winter and the beginning of spring.At the beginning of spring, plants use a lot of energy to flower and leaf out. It isn’t until they leaf out that they begin making food again.The early summer drought put a lot of stress on all plants from the biggest tree to the smallest blade of grass. Lack of water reduced their ability to manufacture food (photosynthesize) and distribute it through the plant. They are having to play catch-up now, so any help you can give them will bring them back to health sooner.Fertilizer should not be applied just because you have always done it. It should be applied to meet specific objectives. A soil test is your best investment for confirming whether your soil needs fertilization or not.