It’s fall, so back off the fertilizer

Shannon Wright adjusts the proprietary liquid fertilizer mixture used to grow hemp in the arid, high desert climate of the San Luis Valley. (John McEvoy Special to The Colorado Sun)

Although I’m a huge fan of fertilizer, there is one time of the year when it shouldn’t be applied, and that is during the fall season.

Gail Vanik

Fertilizer sends nutrients to your plants that gives them the message that it’s time to grow, which is why it’s important to use it in spring and summer. This is the active growing season for trees, shrubs, perennials and annuals. When the days get short enough, chlorophyll isn’t produced, and the leaves change color and eventually fall.

Plants don’t like longer, cooler nights and shorter days, so the sap slows in preparation for winter. All these processes prepare your plants for the dormant state that is quickly approaching.

In fall, Mother Nature sends the message that it’s time to slow down. Why would you want to feed a plant to encourage it to grow when nature is telling it that it’s time to stop? It’s counter-intuitive.

There are a few exceptions. One is winterizer fertilizer or other lawn food for your lawn. You will want to use this to strengthen the root systems in your grass before the arrival of winter. Since grass is a relatively small plant above ground, but with a good root system below the surface of the soil, it’s important to give it one final boost heading in the cold season.

Another exception would be your houseplants. They will enter a semi-dormant state through the winter months, but you can still give them some fertilizer, though it isn’t necessary. If you do choose to give them some food, cut it to half strength and don’t apply it very often. Make sure you cut back on the water too because they will require less of that too since they aren’t actively growing now. In short, give them enough food and water to keep them alive and healthy, but don’t overdo either.

When the days begin to lengthen as we move toward spring, be sure to resume your fertilizing schedule. Generally an application in April, June, and a final one in early August will do for most trees and shrubs. Consider how you would look or how healthy you’d be if you didn’t eat on a regular basis – it’s the same for your plants. Don’t apply fertilizer after about Aug. 10, because by then these plants will be starting their fall shutdown processes.

The key with fertilizer is to give plants all they need when they’re actively growing during summer, but back off in fall and winter when they are either in a dormant or semi-dormant state. If you carefully choose which fertilizer to use and how often to apply it, you will keep your outdoor landscape and your indoor plants happy and healthy until next spring when they’ll start to actively grow once again.

Gail Vanik can be reached at 970-565-8274 or by email at fourseasons@animas.net.