Brochure - Syngenta Primo HG - 251014
Applies to Primo HG | Turf Growth Regulator
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Making Good Turf, Great
PRIMO® HG Turf Growth Regulator will promote greener, denser, more resilient lawns, reduced height of leaf growth, fewer clippings and therefore less time spent on maintenance. PRIMO® HG is the trusted growth regulator that pre-conditions turf for stress and optimises surface quality and colour. Achieve professional turf quality at home.
What PRIMO® HG Turf Growth Regulator offers you:
- Enhanced turf quality and colour with finer, denser growth
- Reduction of excessive leaf growth throughout summer – meaning less mowing plus reduced clipping removal and less potential for scalping
- Redirects the plants energy to the root system – treated turf grows a stronger, deeper and more robust root system, improving the ability of your turf to utilise available water and nutrients
- Pre-conditions your lawn for hot, stressful summers – better heat stress tolerance, less wear and tear, and reduced watering needs
- PRIMO® HG can slow turf leaf growth for up to 4 weeks – so if you are going on holiday, one application prior to leaving means that your lawn doesn’t get out of control while you’re away
- Available in an easy-to-use 500 mL twin chamber pack
Always read the label before use. Syngenta Australia Pty Ltd, Level 1, 2 Lyonpark Road, Macquarie Park NSW 2113. ®Registered trademark of Syngenta Group Company. ™Trademark of a Syngenta Group Company. All products written in uppercase are registered trademarks of a Syngenta Group Company. © 2025 Syngenta. SB 25-305.
For more information, scan the QR code, visit or speak with your local Syngenta Territory Sales Manager.
Primo® in Action
[Image: Comparison of treated vs untreated couch field. Treated lines show significantly reduced leaf growth and no seed heads.]
PRIMO®’s impact on turf in a couch field. The PRIMO® treated lines show the couch leaf growth is significantly reduced. It also prevents the couch from producing a seed head at certain times of the year.
[Image: Comparison of treated vs untreated Kikuyu.]
Kikuyu under PRIMO® Program PRIMO® shortens the internodes in turf and makes the surface a tighter, denser and more attractive looking surface, with less mowing.
[Image: Green line in the middle of a lawn showing the effect of one application.]
The green line in the middle is a great example of what one application of PRIMO® can do to your lawn before going away. The scalped areas either side are untreated and require a significant amount of leaf to be mown when you return, where the treated area only required a small amount of leaf removed, hence why it is still nice and green.
[Image: Comparison of treated vs untreated grass.]
Treated area shows reduced grass height, with a finer, denser surface compared to untreated area, where the surface is uneven with taller grass. Professional managers use PRIMO® to ensure a consistent, high quality and attractive surface.
The only turf growth regulator registered for home use in Australia
Primo® Hg Turf Growth Regulator: How It Works
PRIMO® HG is absorbed through the leaf and works by reducing the elongation (length and size) of stems, stolons and leaves in the above ground parts of the turf plant. The root system is not affected but does benefit from the efficiencies that result from reduction in excessive leaf/stem growth. PRIMO® HG has no root absorption, therefore targeting the foliage on application is critical for best results. The smaller leaves and shorter internodes on stolons result in much less physical upward growth and thus reduce mowing, clipping removal and plant injury.
Increasing the amount of PRIMO® HG applied will increase the level of regulation applied. Adjust rates to desired level based on turf health, growing conditions, level of wear from use etc. Rates typically start low in spring, increase through summer then reduce into autumn.
Primo® Hg Can Be Used as a Growth Regulation Tool on the Following Turf Species:
Warm season turf grass Bahia Grass, Buffalo Grass, Carpet Grass, Common Couch, Couch hybrids and varieties, Kikuyu
Cool season turf grass Bent Grass, Fescue, Perennial Ryegrass
Calibration
To get the best from any application of product to your lawn whether it is chemical or other, it is important to calibrate your sprayer to know how much water you are applying. Follow this step-by-step guide for calibration.
STEP 1: Calculate your walking speed
- Measure out a 10 m strip.
- At your normal walking speed, time how long it takes in seconds to walk the 10m.
- Repeat back in the opposite direction and take the average.
- Use the formula to calculate your walking speed (3.6 x 10 divided by time in seconds).
- Example: 3.6 x 10 = 36 divided by 9 seconds (average) = 4 km/h. [Diagram: Person walking 10m, formula 3.6 x 10 / time = km/h]
STEP 2: Calculate spray application rate
- Fill your sprayer with water and pressurize.
- Using a measuring container, spray water into it for 1 minute and measure how much in litres (output).
- On a hard surface such as concrete, spray water onto it at your normal spray height. Measure the width of the spray in metres.
- Using your output and width, use the formula to calculate application rate: (600 x sprayer output (L/min)) / (Swarth width x walking speed (km/h))
- Example: The sprayer output for 1 minute recorded 2 L of water for 1 nozzle and on concrete it measured 1 m wide. (600 x 2) / (1 x 4) = 1200 / 4 = 300 L/ha [Diagrams: Measuring output in litres in 1 min; measuring spray width in metres]
Application Table
| Situation | Grass type | Rate | Comments |
|---|---|---|---|
| Established lawns and turf grass | Buffalo grass, Common couch, Hybrid couch eg Greenlees Park, Santa Ann, Wintergreen | Use 10 – 40 mL per 10 L of water and spray over 100 m² | For best results apply PRIMO® HG when lawns are actively growing, well maintained and receive regular water and fertiliser applications. Use the lower rates when grass growth is moderate. Use higher rates when grass growth is vigorous or when longer periods of 4 to 6 weeks regulation are required. Repeat applications can be made as soon as turf resumes growth or if more suppression is required. Apply as part of a program to maintain ongoing regulation of growth. |
| Kikuyu | Use 20 – 80 mL per 10 L of water and spray over 100 m² | ||
| Fescue grass, Perennial rye grass | Use 20 – 60 mL per 10 L of water and spray over 100 m² | ||
| Carpet grass, Bent grass, Bahia grass | Use 20 – 40 mL per 10 L water and spray over 100 m² | ||
| Winter grass reduction (in Bent grass) | Use 4 – 10 mL per 10 L water and spray over 100 m² | Winter Grass Management in Bent Grass. Apply at peak growth periods. Low rates of PRIMO® HG can provide growth suppression of Winter Grass but not Bent grass. This can enable a transition towards a higher percentage of Bent grass. |
Refer to the registered label for full details and instructions for use. Follow label directions for recommended water rates. If it needs to increase, then look at changing nozzles to a higher output, increasing pressure and slowing walking speed.