Improve turf health and reduce lawn upkeep with a plant growth regulator

By Matt Giese, M.S., technical services manager for Syngenta

An effective plant growth regulator offers several benefits for homeowners and can help reduce the work needed for lawn upkeep. Primo Maxx® plant growth regulator slows foliar growth by stopping the production of the plant hormone that affects cell elongation. In other words, the above-ground parts of the plant do not extend vertically, so turf growth is reduced by about 50% for up to four weeks.

Benefits of a plant growth regulator

For over 30 years, lawn care operators have seen outstanding success with this formulation. Today, Primo Maxx continues the legacy, providing excellent benefits.

Multiple applications of Primo Maxx, along with good cultural practices, can offer:

  • Reduced mowing frequency by 30-50%
  • Reduced turf water use
  • Decreased mowing time, as clippings are greatly reduced and can be left on the lawn to decompose, adding nutrients back to the lawn
  • Improved turf density, color and quality
  • Increased turf wear tolerance
  • Improved drought tolerance
  • Reduced maintenance around landscapes and hardscape areas when used as an edging tool
  • Reduces the risk of scalping by compacting the turf
  • Preconditions plant to withstand summer stresses
  • Concentrates chlorophyll in shorter leaves, resulting in a darker green color
  • More extensive root system to support plant growth during summer stress

When to apply

Excessive turf growth from fertilization or spring temperatures and rainfall can be reduced with Primo Maxx, which works best on high-quality residential and commercial turf areas. Repeat applications every four weeks when the turf is growing. During summer stress or winter dormancy, pause Primo Maxx applications until turfgrass growth resumes.

Apply Primo Maxx with spray-gun application devices, hand sprayers and backpack sprayers in 0.5-4 gal. of water per 1,000 ft.2 Primo Maxx should be allowed to dry on foliage for one hour after application. A spray dye is recommended to help improve application accuracy. Application rates are influenced by turf species.

Primo Maxx rates for four weeks of growth suppression (fl. oz./1,000 ft.2)

Turf typeResidental/commercialEdging/banding
Tall fescue0.751.0
Kentucky bluegrass0.60.5
Kentucky bluegrass/fescue/rye0.751.0
Perennial rye1.01.0
Common bermugagrass0.751.0
Hybrid bermudagrass0.250.5
St. Augustinegrass0.100.4

Primo Maxx is now available in a convenient 4-fl. oz. bottle, perfect for smaller lawns.

For more information, visit or contact your local Syngenta territory manager.

Always refer to the product label for full use recommendations.

All videos are either the property of Syngenta or are used with permission.

© 2024 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties and/or may have state-specific use requirements. Please check with your local extension service to ensure registration and proper use. GreenCast®, Primo Maxx® and the Syngenta logo are trademarks of a Syngenta Group Company.

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