3/27/2018 - By Harrell's

Are you ready for some football? Seems that the fall of the year is a time when a lot of attention is given to football instead of directing your attention to where it should be – your turfgrass!

Fall is the most important time of the year for many turfgrass management duties.

The most important fertilizer application of the year should be made in the fall. This is the time of the year when all plants are generating their food reserves (carbohydrates) for the upcoming winter so they are able to recover in the spring and survive. This is a genetic mechanism and therefore, the most important fertilizer application you need to make every year.

It is recommended that mowing heights be increased this time of year to allow for more leaf area to develop to increase the photosynthetic capacity of the turfgrass plants. This is very important for supporting the manufacture of food reserves as an increase in photosynthesis equals an increase in carbohydrate production.

This fall fertilization is needed to supply the nutrient sources required to manufacture these food reserves in the plant. So, get those spreaders back out and calibrated.

The ideal time to make this fall fertilizer application would be when the turfgrass has shown signs of decreased clipping production, but the roots are still actively growing. The table below shows the optimum temperatures for shoot (leaves) versus root growth for both cool- and warm-season turfgrasses.

Table 1. Optimum temperatures for cool-season and warm-season turfgrass growth.

As a reminder, this fall fertilization should also include potassium (K) as a component of the fertilizer applied as K is very important for plants for improved cold tolerance and K also regulates the water content of plants. Potassium is key to trying to minimize turfgrass loss due to winterkill.

Fall should be a time when we address weed control or shall I say lack thereof. Given this past summer, there are a lot of summer annual weed escapes left over from breakthrough from preemergence herbicide failure in late summer. Weeds like crabgrass, goosegrass, and spotted spurge are “sticking out like a sore thumb” in many lawns and landscapes and should be removed to prevent them from contributing to the soil seed bank. Now would be an ideal time to apply a postemergence herbicide to control these summer annual weeds and apply a fall preemergence herbicide for preventative weed control of winter annual weeds such as annual bluegrass (Poa annua), dandelion, and wild onion. Herbicide selection should be based on the type(s) of desirable turfgrass that you are treating to insure no injury occurs from this application going into winter dormancy. Injury at this time would only further deplete the food reserves in the plant. Consult your local Harrell’s sales representative to determine the best options for herbicide selection for these opportunities.

Fall is also a great time to address weed control in the landscaped areas. A fresh layer of deep mulch should be applied as it will aid in reducing weeds over the winter. If heavy weed pressure has been noted in these areas in the past, then a preemergence herbicide such as Snapshot or SureGuard should be applied to prevent weed germination and establishment over the winter.

Fall should be the time of the year when many of the perennial plants and trees are pruned. It is recommended to consult a certified arborists to make sure your pruning efforts are not only effective but promote improved health and growth of the plants.

C’mon man, don’t fall short on your turfgrass maintenance practices this fall and pay for them next spring.