Never Underestimate the Importance of Late Fall Fertilization

Although this may appear to be the time of year where daylight is shorter, temperatures are cooler and operating budgets tend to tighten up, fall is the best time of year to fertilize your turf, trees, shrubs and groundcovers. Late season fertilization, sometimes referred to as fall fertilization, has been utilized by turf managers and landscapers for years. This type of fertility program involves the application of much of the season’s nitrogen, phosphorus and potassium during the late season months of October through December. It is important that late season fertilization is not confused with dormant and/or winter fertilization.

Late season fertilization has become popular because of the many agronomic and aesthetic advantages attributed to its use that aren’t realized the same as with spring and summer applications. Advantages of the late season concept include better fall and winter color, earlier spring green up, increased shoot density, improved root growth and enhanced storage of energy reserves (carbohydrates) within the plant.

For many during this time of the year, turf growth begins to slow and leaves continue to fall, and the mindset is to reduce the amount of nutritional inputs into our landscapes. However, contrary to this belief, the plant materials benefit most as they receive adequate amounts of nitrogen, phosphorus and potassium in a 3:1:2 ratio respectively.

The nitrogen helps to provide continued greening and shoot growth before the onset of extreme cold temperatures. Whereas, phosphorus aids in the development and strengthening of the plant’s root systems, respiration and cell division going into the winter months prior to the dormancy of the plants. Finally, potassium is essential in the prevention and resistance to diseases and pests, frost damage and drought (freeze and thaw) that can potentially go unrecognized during the most difficult times of the year.

As with any late fall fertilization program, it can vary depending on turfgrass species (whether they’re cool season or warm season), trees (whether they’re evergreen or deciduous) and groundcovers that may be more woody or ornamental. Also, it is recommended to conduct a soil test prior to fertilizing so that the correct amounts of necessary nutrients are adequately applied. Care should be given prior to the application of any fertilizer, by adhering to local weather forecast, as to avoid applying before any major rain events that may create runoff or leach out the fertilizer to unwanted areas or storm drain/watershed areas.

Just remember, that as we humans tend to store up our bodies with carbohydrates, vitamins and nutrients, as well as cold and fever remedies going into the late fall and winter months. It is a reminder that we take notice to provide our turfgrass and landscaped areas with their own means of enduring the harsh realities of what is to come in the months ahead. Never underestimate the importance of late fall fertilization.