What to consider

While most liquid products are labeled to be sprayed in temperatures of up to 90 degrees Fahrenheit, Benjamin Moretta, owner of Moretta Lawn & Landscape in Canton, Ohio, says he usually only applies liquids at temperatures below 80 degrees. This means he will typically make applications in the early morning in summer.

“I like to leave as soon as the sun comes up and be done by 2 o’clock in the afternoon,” he says. Moretta also prefers to spray only when wind speeds are below 10 miles per hour.

Granular products typically do not require as strict guidelines for application. “With the granular insecticide that I use, I like to make sure there’s adequate soil moisture or there’s potential for some rain coming up because that product needs to get into the soil,” Moretta says.

Some products may not last as long if there is a lot of rain or high temperatures during a season, says John Benefield, lawn care specialist at Green Leaf Nursery based in Glasgow, Kentucky.

“If we get a lot of heat and a lot of humidity and a lot of rain, and it causes that pre-emergent to volatilize, and typically toward the end of the season, you see outbreaks of crabgrass and stuff, so that plays a factor also,” he says.

In case of mistakes.

Moretta says he hasn’t had any notable application mistakes. If a mistake were to happen he would document what he did and why the error occurred. He would also repair the damage made by the application and cover all expenses associated with that.

“It just typically depends on the mistake. If I were to spray a product where it’s not needed and it may harm a landscape plant, I will always try to notify the customer and let them know of my mistake. It may not harm the plant at all, or it may lead to us replacing the plant,” Benefield says.

A spill kit is kept on the truck at all times in case of a chemical spill.

“If we were to have a chemical spill, typically you’ve got to call a chemical agency and let them know of the spill, but we have like a spill kit system that we can kind of contain that spill and take care of it,” Benefield says.

As a best practice, he says it’s vital to keep track of every application made and details surrounding the application such as the date, why it was made, amount of product applied, type of product and more. This information may also be requested by a local inspector.

Proper equipment maintenance.

Both contractors say checking the calibration on their spreading equipment is paramount. Moretta uses a skid sprayer.

“Making sure that the output’s correct, that’s crucial,” he says. “If you don’t put out the right amount of weed control product there’s a potential that you’re not going to get any kill out of it. If you put down too much there’s potential you could burn the turf.”

Benefield uses a sprayer that sprays liquid and granular at the same time. He tries to perform maintenance on the machine according to the recommended schedule in the owner’s manual.

“I always just make sure all the fittings are greased. I change the oil every 100 hours,” he says.

Lastly, Benefield recommends paying attention to whether the product is being spread evenly. “You don’t want your spreader to be spreading more on one side than the other. That can make the lawn look bad,” he says.