Using Plant Growth Regulators to Manage Facility Landscapes

By Rebecca Knapp, CSFM

Managing a sports field complex goes far beyond maintaining pristine turfgrass. Plant growth regulators (PGRs) are often an unfamiliar concept outside of turf management, but these products can be highly effective tools for managing landscape plants and trees around sports complexes.

Why would sports field managers want to slow down plant growth? Surprisingly, using PGRs can lead to significant labor savings, reduced maintenance costs, and healthier plants — all while keeping sports facilities looking their best.

Surrounding landscapes (including trees, shrubs, and ornamental plants) play a critical role in creating an inviting and professional atmosphere for athletes, spectators and staff. However, balancing the demands of busy sports schedules, limited staff and shrinking maintenance budgets can be challenging. This is where PGRs come into play — not just for turfgrass but also for managing trees and landscape plants.

How do PGRs work?

PGRs are chemical compounds that influence plant growth by modifying hormone activity; and have long been used in turfgrass management to reduce mowing frequency. Early PGR formulations were similar to herbicides, limiting growth by blocking cell division. Although this helped to reduce plant height, it often caused side effects such as leaf yellowing, distortion and, in extreme cases, defoliation.

Modern PGR formulations are much more refined. They work by inhibiting the gibberellin hormone, responsible for cell elongation. This means plants still produce the same number of cells, leaves, buds and shoots — but with 30 to 70 percent less growth. This reduction can extend pruning intervals for landscape plants around sports fields, where frequent trimming can be time consuming and costly.

Optimizing sports field landscapes with PGRs

Sports field managers face unique challenges. Consider a multi-sport complex with frequent events from youth soccer tournaments to high school football games; maintaining these highly visible, multi-use facilities that endure heavy foot traffic, weather extremes and minimal downtime is often a year-round task for landscape crews. These complexes often include trees, shrubs, hedges and ground covers that require routine maintenance around the entire facility, including fences, parking lots, dugouts, scoreboards, walkways and spectator stands. Applying PGRs can reduce the need for pruning these numerous plants, making landscape management tasks much more time efficient.

Key benefits to implementing PGRs in your operations

1. Growth regulation, reduced pruning and trimming frequency

One of the biggest advantages of using PGRs is reducing the need for frequent pruning and trimming. Around sports fields, landscape plants such as hedges, shrubs and trees near walkways, bleachers and parking lots often require frequent maintenance to prevent overgrowth.

Operational efficiency means more time can be allocated for field maintenance, game preparation, irrigation system maintenance and other essential tasks. Well-maintained shrubs and trees enhance the visual appeal of the overall facility, without constant upkeep.

The shrub on the right was treated with a plant growth regulator and experienced reduced growth, less green waste and more efficient use of plant energy.

2. Enhanced plant health and stress tolerance

PGRs do more than just reduce growth — they can also improve plant health. PGRs encourage root development and boost drought tolerance, stimulating the production of abscisic acid (ABA), a hormone that helps plants manage water loss by closing the stomata during drought conditions. Health benefits for sports field landscapes:

The plant growth regulator helped produce thicker, waxier leaves, which results in less water loss and a reduced potential for the leaf scorch you see on the untreated cutting above it.

Improved drought resistance: Treated plants develop thicker, waxier leaves, which improve drought resistance by reducing both leaf scorch and water loss. This is particularly valuable in areas with high sun exposure, temperature extremes and windy conditions.
Stronger and enhanced plant health: PGR applications promote fine root development, enabling plants to access water and nutrients more effectively. An increase in chlorophyll production leads to deeper green leaves and boosts overall tree and shrub health while reducing chlorosis symptoms — keeping landscapes both visually appealing and functional. Additionally, reduced pruning wounds result in healthier, more resilient plants.
Disease suppression: PGRs thicken leaf surfaces, making it harder for fungal disease to take hold. Because of this secondary benefit, studies have shown that PGR-treated plants are less susceptible to certain pathogens, such as leaf spot and cankers.

3. Labor and cost savings

Labor shortages and tight budgets are common challenges in the industry. By reducing pruning and green waste disposal, PGRs can generate significant labor and cost savings. Less frequent pruning also reduces fuel costs for equipment, sharpening cutting surfaces, and overall wear-and-tear – ultimately extending the lifespan of tools and machinery.

In trials, highly manicured shrubs treated with PGRs required 60 percent less pruning over a 12-week period, and green waste was reduced by 50 percent. These savings allow sports field crews to focus on essential tasks such as mowing, edging, and field maintenance instead of repetitive pruning.

4. Safety, reduced liability, and visibility improvements

Overgrown trees and shrubs can create safety hazards by blocking visibility around sports complexes. Walkways, entry points and parking lots must remain clear and safe for visitors. PGR-treated plants stay within desired size limits longer, reducing the risk of overgrowth-related hazards. PGRs can assist with ensuring sidewalks remain free of overhanging branches, preventing trees and shrubs from blocking security cameras, facility lighting and signage. This also improves traffic safety and reduces liability by helping maintain clear sightlines around entrances and exits.

5. Sustainability and environmental impact

Sustainability is increasingly important for sports field managers looking to reduce their facility’s environmental footprint. PGRs support eco-friendly practices by reducing green waste and water use while lowering emissions. With reduced pruning, there’s less plant material to dispose of, decreasing landfill contributions. Fewer maintenance tasks mean lower emissions from power tools and transportation, while enhanced root systems improve drought tolerance and reduce irrigation needs.

Best practices for applying PGRs

To maximize the benefits of PGRs, sports field managers should follow these application guidelines:

Select the right PGR: Choose products formulated specifically for trees and landscape plants. Be sure that the label includes woody plants, trees or shrubs based on the facility’s specific landscape features.
Timing matters: Apply PGRs during active growing seasons when plants are expanding. If trimming prior to application, consult the label for application timing post-trimming.
Proper application: Use trained staff or certified applicators to ensure even coverage and avoid over-application.
Calibrate equipment: Uneven applications can cause inconsistent growth regulation.
Follow-up monitoring: Observe plant response and inspect treated plants regularly to adjust maintenance schedules accordingly.
Regulatory: Follow all local regulations and product label instructions.

A section of this ficus was treated on May 6 via foliar application, and both cuttings were taken around eight weeks later (on June 30). The cutting that was treated with a plant growth regulator experienced greater chlorophyll production and less growth, resulting in a healthier – and more visually appealing – shrub.

Take Control of Your Landscape

PGRs are an invaluable tool for sports field managers looking to optimize their field management programs while maintaining high standards of landscape care. With tight maintenance schedules, limited staff, and growing responsibilities, sports field managers can’t afford to let landscape plants dictate their workload. PGRs offer a proactive, valuable management solution that helps crews maximize productivity while ensuring plants stay visually appealing — all while reducing labor demands, saving costs, reducing unwanted growth, and promoting healthier, more-resilient plants.

By integrating PGRs into plant health care programs, sports field managers can create safer, more aesthetically pleasing complexes while allowing their crews to focus on what matters most – keeping the playing field game ready with critical tasks such as cultural practices, field preparation and maintaining irrigation schedules.

The next time you walk through your sports facility, consider the hedges, ground covers and trees that need constant trimming. With PGRs, you can take control of plant growth, allowing your crews to stay ahead of maintenance while keeping the site looking professional year-round.

Rebecca Knapp, CSFM, is a technical advisor for Arborjet | Ecologel. She is a Certified Sports Field Manager, International Society of Arboriculture Certified Arborist and earned a Sustainable Landscape Management certificate from the Arizona Landscape Contractors Association. She focuses her time on supporting sports field managers, golf course superintendents and turf/plant health care professionals with solutions for soil, plant nutrition and water efficiency. She can be reached at rknapp@arborjet.com.