Sports Turf Agronomy Advice - March 2025
Thankfully, February has been much drier compared to last year, when 168mm of rainfall was recorded in the diary. This allowed much-needed maintenance to take place and winter projects to be completed.
Sunrise over a frosty morning at St Enodoc, Cornwall.
Although February was drier, January remained a wet month, bringing its own challenges and making some areas difficult to manage. Hopefully, if conditions improve in March, further progress can be made. It doesn’t feel like it, and the data doesn’t reflect the ‘false spring’ effect we have seen in previous February’s. Although growth hasn’t really started yet, the dry weather has allowed some managers of fine turf to begin renovations. Those who started early in the month have seen at least some recovery. If the upcoming weather is as unpredictable as previous springs, there is certainly merit in utilising these windows of opportunity.
Before looking ahead to the forecast for March, let’s review February’s weather data. Rainfall was heaviest in week three, with temperatures dipping mid-month before rising toward the end. However, as daytime temperatures increased, night-time temperatures dropped due to clear skies. GP figures and base nitrogen requirements indicate minimal growth so far. A spike in week seven provided a small boost, but cold nights in week eight prevented sustained temperature-driven growth.
Click here to review weather data in your region for February. To keep up to date with the weather throughout January visit https://academy.agrovista.co.uk/category/weather
The early March forecast looks fairly settled overall, with most variability in the first week. The cold temperatures seem to have passed, and importantly, there are no extreme nighttime lows. This will help soil temperatures rise, especially with over 20 days forecasted to have maximum temperatures above 10°C. This gradual increase will influence plant growth rates. While growth won’t surge immediately, recovery should begin.
Interestingly, another blog post highlighted that using a 6°C GDD model, by the end of February there were 43 GDD, whereas in the previous three years, similar levels were reached on February 3rd, 3rd, and 14th, respectively. This illustrates how much cooler February has been this year. That being said, those who carried out early renovations should see slow but steady recovery.
Plant Growth Regulation
Poa annua seed head development can start early, especially given today’s unpredictable weather patterns. These shifts put extra stress on Poa annua, which, as part of its survival strategy, produces seeds in stressful conditions - a process that consumes significant energy. Applying a plant growth regulator formulated for cooler conditions, such as prohexadione calcium, can interfere with and suppress seed development. This redirects energy away from seed production toward other processes, such as tillering and root growth, improving overall plant health during stressful periods.
Successful maintenance depends on effective recovery. Applying a fertiliser with suitable nitrogen sources - such as nitrate and ammonium, which are readily available for plant uptake - stimulates growth and recovery. Nitrate is highly mobile, reaching plant roots quickly and promoting growth in cooler conditions. Ammonium also provides a readily available nitrogen source and binds to soil minerals, making it less mobile than nitrate.
As soil temperatures rise, microbes will rapidly convert ammonium to nitrate through nitrification. Using a nitrogen source that isn’t readily available may not provide the desired growth response. Methylene Urea (MU), a slow-release nitrogen fertiliser, decomposes through microbial activity, which is temperature-dependent. Organic fertilisers, derived from plant and animal materials, release nutrients more slowly and less precisely than conventional fertilisers, leading to a delayed turf response.
For those not performing maintenance that requires recovery from surface disruption, liquid fertiliser applications timed with rising temperatures may be sufficient to gently ‘wake up’ the turf. This can provide the necessary response before granular applications later in the spring, when temperatures have risen further.
Tom Wood
B.Sc (Hons) | BASIS | FACTS
