When leaves and flowers begin to die back in the fall, it will look like all plant activity has finished for the season. However, cooler temperatures and shorter days send signals to plants to slow down on the above ground growth and concentrate on what's underground.
With an inordinate amount of activity taking place in the roots, fall is the opportune time to fertilize. It may sound odd to feed plants now, but an ample supply of fertilizer in the fall will give plants a head start when it's time to grow in the spring.
Plant needs are different in the fall than in the spring and summer. In warmer months they are busy leafing and blooming, while in the fall, all their energy is going to the roots. Since nitrogen inspires above ground growth, look for fertilizers with a low amount of nitrogen for fall applications.
Each fertilizer will have a ratio on it, typically expressed as N-P-K. N stands for nitrogen, P for phosphorus and K for potassium. A fertilizer rich in phosphorus and potassium, while low in nitrogen (between 2 and 5) will be ideal for this time of year.
At Estabrook's, we recommend organic fertilizers from Espoma. An all-purpose formula like Plant-tone or Holly-tone for acid loving plants both offer a good amount of phosphorus and potassium while limiting the amount of nitrogen your plants receive this time of year.
The best time to fertilize in the fall is after a few light frosts or when trees begin dropping their leaves. Lightly scratch granular fertilizers into the top of the soil and where appropriate, apply a nice layer of mulch over the top. Water the fertilized areas thoroughly if fall rains are lacking.