Start spring off right with fall fertilization

As the season shifts to late fall, experts say the nutrition needs of both cool- and warm-season turf change. Experts share what lawn care operators (LCOs) need to keep in mind this fall and how to get turf off on the right foot for next spring.

Ben Pease, Ph.D., turfgrass agronomist for The Andersons Plant Nutrient Group, says as cool- and warm-season goes into dormancy in late fall, LCOs need to be mindful of the fertility applied.

Ben Pease

“You don’t want to overstimulate turf that’s about to go into dormancy,” he says. “Use a controlled-release fertilizer to put down small amounts of nitrogen that will go out slower than a fast-release version.”

John Perry, president of Greene County Fertilizer Co., says LCOs should see late fall fertilization as giving the turf a leg up for next year.

“The best way to think about fertility in the fall is that you’re actually applying your first spring fertilizer — it is just taking place in the year prior,” he says.

Perry suggests LCOs use soil temperature as a gauge to apply controlled-release fertilizers.

“Once the soil temperatures drop below 50 degrees, it would be better to switch over to a controlled-release fertilizer,” he says. “Even though it might have more of a delayed response in the springtime, it would still be a more stable choice.”

Bill Abetz, director of turf and ornamentals for Pursell Agri-Tech, suggests that LCOs look for a 10-0-30 NPK (10 percent nitrogen, 30 percent potassium and 0 percent phosphorous) ratio to help the turf better overwinter.

“The reason you’re doing that is to enhance or improve plant health through dormancy,” he says. “Potassium makes plants stronger. It helps them overwinter better. It helps them in and out of dormancy.”

Use late fall to address soil needs

Bill Abetz

Pease says LCOs also should use late fall to apply soil amendments, such as gypsum, lime or humic acid.

“You could still fit another application of any of those soil amendment-type products along with your fall fertility application,” he says. “Some fertilizers do have those as a component.”

Fall aeration is another opportunity for an application of fertilizer as the turf will take up the fertility quickly, Pease says.

“If you’re doing a later aeration, there’s still some recovery happening in the spring,” he says. “It’s good to partner a late fall aeration with some late fall fertility so that you can promote recovery. If they’re overseeding with that fall aeration, that’s another good time to put down a small dose of fertility to help those new seedlings get started.”

Perry says LCOs with cool-season turf should not overlook a fall round of fertility as the turf went through a second phase of growth and depleted some nutrition reserves.

“You basically have a growth phase and then immediate dormancy, and then it has to wake up and have something to latch on to early in the season,” he says.

What to avoid

John Perry

Avoid overstimulating the turf going into the winter and then again in early spring, Pease says. It could deplete the soil’s reserves and make the turf more susceptible to stress in the summer.

“The mistake of possibly overfertilizing with too much faster-release (fertilizer) and getting a big growth spurt (next spring) could be a detrimental mistake,” he says.

Abetz says not fertilizing in the fall would be a mistake. If that’s the case, he says LCOs need to think about fertility levels in the soil as turf comes out of dormancy and then apply nutrition as needed.

“In the spring, do soil testing on some properties to see where your soils are so that you can figure out exactly where you need to be from a rate perspective,” he says. “Because if they’ve depleted their soil reserves, they might not have as much fertilizer as they’re used to having in the spring.”