FROM THE FIELD To Grow or Not to Grow

For years, lawn care and landscape professionals have heard intriguing talk of products that would keep plants green while limiting their growth, thereby reducing maintenance demands. Such products’ potential is obvious. Companies could provide customers with green landscapes that never look overgrown or in need of maintenance work. Plus, a reliable product could provide users with a new service to offer customers. 

Of course, the key word in all of this conjecture is “could.” While talk of such products, typically called plant growth regulators (PGRs), has been around for years, the reality has never matched the hype. As a result, PGRs have been largely limited to golf course applications where their work limiting the growth of certain varieties of low-cut grass and not others makes them a useful control tool.
 
Lawn care and landscape results from the same products haven't been as strong, however, as the taller-grown grass favored in residential and commercial settings typically lost its green color.
 
But in an industry where suppliers are facing increasing pressure to identify truly new products, PGRs have garnered consistent attention, and the results are obvious.

BRANCHING OUT. Lawn care and landscape firms obviously spend more time caring for turf than any other plant, so PGRs that demonstrate effective results on residential and/or commercial lawns are most in demand. They just don’t really exist yet, so any anxiety about a product that eliminates the need for your mowing service is still premature.
 
But the story is very different for ornamental products. We’re just now getting to the point where options exist. The goals for these products are to:

• Reduce trimming/pruning frequency, which results in labor savings
• Increase the plant’s density or compact growth habit, which results in a healthier, more attractive plant
• Suppress shoot growth
• Decrease the internode length, which reduces the need for pruning and saves cleanup time
 
The available products offer similarities as well as differences. Many affect the hormones that drive plant growth. Many also work systemically, which means the plant transports the product through its structure to the growing stems and leaves. Also, the available products come in different formulations – some can be applied only granularly while others can be applied only as liquids.
 
How quickly a product starts working and how long it works varies. Each product has its own claims, with growth suppression starting in as little as one week’s time depending on the product and the plant. Meanwhile, control has been shown to last up to 12 months, again depending on the conditions.
 
Of course, these products should only be used on well-established perennials, and not on ornamental trees or crop plants.
 
Impressive test data is available on a range of plants, including jasmine, ligustrum, boxwood, firebush, thryallis, plumbago and Mexican petunia.
 
The reality is that PGRs continue struggling to earn a widespread acceptance among lawn and landscape professionals.
 
For many years, that skepticism stemmed from poor product performance. But as the product offering continues to improve, products that once threatened to do more harm than good are now serving as an impressive new tool for landscape management success.

J.B. Toorish and Brian Kelley are part of LESCO’s Tech Services Department. They can be reached at
fromthefield@gie.net or at 800/321-5325 ext. 3150 to answer technical questions.