Productivity In A Bottle: Mowing And PGRs

Well, outside of installing plastic plant material and artificial turf, you’re never going to achieve zero growth in your customers’ landscape during the growing season. However, some landscape maintenance contractors have found success managing the growth of turf and ornamentals using judicious applications of products known as plant growth regulators.

These products are synthetic versions of naturally occurring chemicals that trigger a natural response in a plant, either inhibiting the growth process or affecting functions related to growth, such as cell elongation.

Contractors who use PGRs note that they aren’t some magic bullet that will deliver a ton of obvious productivity and more profits. Instead, they represent another tool in the maintenance arsenal that helps companies be professional and keep up with the workload.

TAMING TURF. No one ever promised that the mowing aspect of landscape maintenance would be easy to plan and execute, but weather fluctuations, equipment failure and scheduling hassles can make the job a real nightmare.

This is where turf growth regulators can play an important role, say con-tractors who use the products as a part of a regular maintenance program.

Several years ago, Jim Grow, vice president, Pennink Arrimour, Huntingdon Valley, Pa., began "experimenting" with the use of PGRs in turf. The first test was not successful, he noted, because the amount of nitrogen that accompanied the application offset the effects of the PGR.

After a few seasons of tweaking, however, Grow has established some guidelines for when and where using a PGR makes sense.

The first consideration that comes into play is whether a PGR can be tank-mixed with other products and tied into a regularly scheduled application. Normally, the PGR would be mixed in with the preemergence and broadleaf weed control application and applied after the second cutting. Since the company will occasionally do a fall preemergence weed application and skip the spring application altogether, the PGR is not always an option.

"With our program, there’s no additional cost for the labor to apply the PGR since it’s tank mixed," said Grow.

Applications are made to the entire site, rather than spot treating. "We tried to spot treat at one time, but we weren’t happy with that," explained Grow. "We still had to visit the site, so it didn’t really save us time or trouble."

The main advantages that putting down the PGR provide are flexibility and fewer clippings. "Without the PGR, we would have to double-cut and do extra work to disperse the excess clippings," Grow noted.

Grow emphasized that this is not an application that allows a contractor to skip a mowing altogether. "That’s a misconception that a lot of people have about PGRs," he said. "You can’t really do that. All they do is extend the window within which you need to cut next time. Instead of having to cut every seven days, if you get rain or are delayed on another site, you can extend that window to eight or nine days. With the spring schedule being what it is, that’s a great asset to have."

Grow couldn’t put a dollar number on any tangible savings, but he said PGRs are worth using if they save managers some aggravation. "I try to make this a break-even proposition for the company - we don’t make any money from doing it, and it’s very difficult for us to show a savings in labor or time, Grow explained. "But if it can keep our production people sane, then I’m happy and it’s a benefit to the company."

David George, exterior division manager, The Engledow Group, Carmel, Ind., also commonly uses the product to slow the spring growth surge. George will also specify a PGR is cases where there is unusually small areas of turf to maintain, "We see using a PGR in the spring as an equipment and people stress reducer," said George. "It doesn’t create a great windfall of savings, but it has become an important tool in our mowing program."

ORDERLY ORNAMENTALS. Proper shrub pruning can be a time-consuming process, especially when long stretches of shrubs border walkways and require a lot of attention. This is the type of situation that calls for the use of PGRs said Larry Neuhoff, director of landscape maintenance operations, Landtrends Inc., San Diego, Calif.

"We have one stretch of hedges that runs for more than three miles along a street," explained Neuhoff, who added that the company has been using PGRs for six years. "We use PGRs to reduce the amount of pruning these shrubs require."

Because Landtrends’ policy insists that shrubs are pruned selectively rather than simply sheared, a pruning job is a highly labor-intensive process, Neuhoff explained. The PGR is applied to slow down the growth of these shrubs and reduce the number of times that technicians are sent out to prune.

When pruning is required for these shrubs, crews first go out and actually perform the work. Then, 1½ to 3 weeks later, a spray crew returns to the site and applies the PGR. "The time period after cutting is critical," warned Neuhoff. "If it’s done too soon or too late it will not be effective."

He estimated that the number of prunings required per year is literally cut in half or more. "Without the PGR, we would be trimming the shrubs every four to six weeks," noted Neuhoff. "With the product, we can extend that window to onc per quarter."

One word of caution from Neuhoff was that he generally limits PGR use to durable species of shrubs such as boxwood, taxis and privet. He also said that it’s critical to read the label to ensure that the shrub will not suffer phytotoxicity from a PGR.

Another ornamental use that Neuhoff has for ornamental plant growth regulation is on ivy. PGR applications slow the growth of ivy used in topiary hedges and help reduce the amount of trimming required to keep ivy to a specified height on the sides of buildings, he said.