There are advantages to both liquid and granular fertilizer. The key is to know when to use each type. Using the correct style of fertilizer – and applying it correctly – will keep your clients’ lawns looking green all year long.
Here are a few things to consider when determining the most effective fertilizer for a given site application.
Layout of the Area.
Small, hard-to-navigate spaces may call for hand-spraying of liquid fertilizer, especially for crews that prefer to use machinery in their granular applications.
“We use liquid when we have to do hand applications – so those are going to be bump outs, small islands, hills, anything like that where we can’t get a machine into it,” says Dan Mausolf, general manager at Stine Turf & Snow in Durand, Michigan.
For large, flat areas, Mausolf’s crews prefer using granular fertilizer whenever possible. They typically spread the fertilizer using a metered, calibrated hopper available on commercial spreaders.
“It’s just faster and you can cover more area (with granular fertilizer) as opposed to liquid,” Mausolf says.
Terrain is a key factor in determining the right fertilizer, agrees Kyle Rose, business development office for The Green Team, which has offices in Charlotte, North Carolina, and Roanoke, Virginia. But because Rose’s teams typically spread granular fertilizer on foot using hand-crank spreaders worn over the chest – he prefers granular over liquid for hilly areas.
“We have a lot of hills at our branch in Virginia, so it’s hard for us to use push spreaders,” Rose explains. “A lot of times we prefer granular because we can be more precise and get those areas done. If you’re spraying liquid fertilizer on a hill, you’ll be slipping and sliding all over the place.”
Type of Application Needed.
In Sarasota, Florida, owner Michael Falconer’s Lawngevity crews typically use granular fertilizer for new starts and at key application times throughout the year in order to get “that really nice green lawn that your customer's looking for,” he says.
“It has to do with the amount of nitrogen you want to put out,” he adds. “If you want to put a larger amount out – say, one pound of nitrogen per one thousand feet – you’re going to use granular. If you tried to use liquid at that higher rate, you’d probably get leaf burn. Liquid’s not good if you’re trying to put a heavier amount of nitrogen out.”
In between seasonal granular applications, Falconer’s crews prefer liquid fertilizer as their go-to tool for more frequent maintenance applications.
The advantage of using liquid for maintenance applications is that it allows crews to customize applications for each client, as needed.
“The big advantage is, you can pull up on a yard and if you’re going to spray it with liquid fertilizer, you can mix for what you see when you pull up,” Falconer says. “So if you pull up to a lawn and it has an iron deficiency, you could add a little iron to your mix . . . or if your lawn has insects, you (can) put the insecticide in there. (With liquid fertilizer) you do everything in one shot.”
There’s also the issue of correct application rate. Many crews feel it’s easier to calibrate the correct application rate when using granular fertilizer.
“In my experience, it’s easier to train people to put out the right amount of granular on a property as opposed to spraying liquid, just because everybody tends to walk in a different way or spray in a different pattern (with liquid),” Rose says.
“There are a lot more variables involved with spraying – you have to make sure your gun is calibrated properly. You have to make sure you’ve mixed at the right rate, and that it’s being agitated properly in your tank,” Rose adds.
Windy days can also pose a problem for liquid applications, especially if crews are using low-volume sprayers.
“A gust of wind can pop up, and (with liquid) you can end up spraying fertilizer where it’s not supposed to be,” Rose says.
To increase accuracy of spreading when using granular fertilizers, Falconer recommends using a properly calibrated professional spreader with a side shield, which he developed, to avoid spraying fertilizer into pools or into ditches or other waterways.
For his part, Falconer said it’s possible to achieve spray consistency with liquid fertilizer, but it calls for careful calibration of equipment.
“Every truck is calibrated for the technician,” Falconer says. Lawngevity crews do routine water “bucket tests” with their spray equipment at headquarters to check that they’re releasing around five gallons a minute – which “is about what a person will walk and spread over 1,000 square feet,” Falconer said.
“There are a lot more variables involved with spraying – you have to make sure your gun is calibrated properly.” Kyle Rose, business development officer, The Green Team
Relying on granular as a primary fertilizer type means crews don’t have to wait for access to a tank truck.
“You can be more versatile with granular,” Rose says. “If you’re a smaller operation that has only three or four trucks, and none of them have a tank, you can still send all of those trucks out with granular products. But if you’re doing a liquid fertilizer, you can only send one guy out if you only have one spray tank.”
Using granular fertilizer with slow release can lead to longer activation periods – meaning crews won’t have to reapply fertilizer as frequently. The result: cost savings in crew labor time.
“With granular options, we can use a material that might last 60 days, might last 180 days, or even up to a full growing season here,” Mausolf says. “So there’s more options (with granular). There’s more consistent growth color, throughout the majority of the season. You wouldn’t get that with liquid. You can’t put that much down (in a single application).”
In some cases, there may be a cost-savings effect to using granular fertilizer, particularly when additives are factored in.
“Once you start mixing in potassium and phosphorous into the liquid (nitrogen-based fertilizer), it becomes really, really expensive,” Rose says. “So, it’s actually cheaper to add more potassium and phosphorus into the granular fertilizers than it is to the liquids.”
On the other hand, if you consider crew labor time, there could be a cost savings effect to choosing liquid fertilizer – due to the fact that fertilization, weed control, and insecticide can be done in one spray application, rather than three separate steps.
“When you’re all done applying granular fertilizer, then you have to blow off (sidewalks and driveway) and then (as a second step) you’d have to pull hose and spray weeds,” Falconer says. “Whereas if you’re just doing liquid, you pull hose, and spray weeds and fertilize all in one shot. So, (using) liquid does help our costs.”
Rose agrees that using liquids can mean less walkovers of a property.
“I think you can be more flexible with liquid. You can mix fertilizer, insecticide, and weed killer in one tank and just walk the property one time,” he says. “So, it can be a little more efficient, with a liquid, if you have multiple applications on a property.”
While there are advantages and disadvantages to both liquid and granular fertilizers, one key factor may ultimately tip the scales in the favor of granular: client perception.
Many residential clients appreciate that they can come home from work and literally see evidence that crews have been on site and have applied granular fertilizer. When liquids are used, there’s often no such visual cue that the work has been done.
“There’s always that customer perception – for whatever reason – (where they fear) they might be getting cheated,” Rose says. “If they come home and see that you’ve been there and see that granular product, it gives them peace of mind that the crew did what they were supposed to do.”