Key Tasks for May
The emphasis at this time of the year will be on mowing frequency, as long as there is sufficient moisture within the soil
Mowing. Greens should be mown at least three times a week, with some grooming, verti-cutting or brushing being undertaken on a weekly or twice weekly cycle to improve air movement and reduce thatch levels building up in the sward profile.
The sward will be actively growing due to the increased soil temperatures, coupled with the stimulation of fertiliser applications. Regular mowing will be required to maintain sward height at around 4-5mm. Verti-cutting/grooming fortnightly can be carried out to help speed up the green and help improve the health of your turf.
Aeration should continue, using a mix of micro, needle or star tines which give maximum effect and almost zero turf disturbance.
Regular use of a sarrel roller will be beneficial and the use of micro tines to aerate the green will help reduce soil compaction, 'vent' the root-zone and to allow water to move quickly from the surface and into the root-zone, thus encouraging the turf to root deeper.
Irrigation: Soil and air temperatures usually increase in May, often bringing on the need to irrigate. If soil profiles, particularly sandy soils, are allowed to dry out too much they often become water repellent (hydrophobic), a state when soils can become difficult to re-wet. Often the first areas to suffer on greens particularly crown greens are the high spots on the green. You may need to spend more time hand watering these problem areas.
When you do water, ensure you go to a depth of 100-150mm to encourage the roots to go down to find the water.
Well, after a month of us getting some normality back in our lives, I think everyone is thankful for being able to do a little bit more. It is undoubtably going to be a slow process as we all adjust to venturing a little further and getting to see those people we haven’t been able to for a long while.
Grounds managers up and down the country have been working tirelessly to provide exceptional facilities for all those back playing sport and have done an amazing job. The weather has been very challenging over the last 4-6 weeks, with low to freezing night-time temperatures which has effectively put a stop to any significant growth. April has been the frostiest on record, going back to when records began in 1960; which has meant that recovery from any winter wear or damage has been limited. This has pushed progress a bit further back for some in terms of where they predicted their surfaces would be heading into May. On top of this, it has also been one of the driest months on record with many locations experiencing as little as 1% of the average rainfall in April; further adding to the challenges of the grounds manager. However, as stated in last month’s diary, growth can’t be unrealistically manufactured, and it is advised to work with nature, where possible, rather than try to force growth.
The forecast for May looks encouraging as night-time temperatures appear more favourable and we will have hopefully seen the back of any frosts. This, alongside mid-teen day-time temperatures, with 22 days forecast at 15° or above, will help to start generating some consistent growth, which puts more control back into the hands of the turf manager. The month appears to have a majority of bright days with only a handful forecast with rain. Historically, May can be seen as the month when spring really starts to take shape. The peaks and troughs of temperatures experienced in previous months start to settle down and the grass plant makes the most of the warmer temperatures and longer days, resulting in an significant increase in growth.
Many will now be well into their programmed approach to plant nutrition for the year, with possibly two or three fertiliser applications already made. Given the recent weather challenges from the extremely low temperatures, many will also still be waiting to see much response from the latest application, depending when it was timed. Acknowledging the recent stress that the plant has been under from the extremely low amounts of rainfall we have had, or the stress from cold irrigation water, which has been applied out of necessity, it is important to plan to help mitigate or alleviate these stresses that the plant has been under. Undoubtedly, once growth gets fully up and running the undesirable annual meadow grass (Poa annua), which will make up many sward compositions across the country, will be responding with its survival strategy…seed.
The onset of seeding brings with it an undesirable impact on playing quality, performance and overall aesthetics. Although grooming can be deployed to physically remove the seed, in some instances, and depending on the surface you manage, this can provide the perfect seed bed for those seeds which don’t make the journey into the grass box and fall back into the sward. At the time of year when growth is consistent enough to provide even swards, after weeks of the grasses in mixed swards all growing at different rates, it is key to manage this to ensure even growth is achieved. An even sward increases playing quality of the surface being managed and, in line with this, plant growth regulators can be used to great effect to help regulate the flowering capacity of the Poa annua plant.
Prohexadione- calcium (Class A late gibberellin inhibitor) can be used at cool temperatures and is active when sprayed onto the plant, therefore its regulatory effect is fast acting. A key benefit of this active ingredient is that it regulates Poa annua closely aligned with the desirable perennial grasses in the sward. This restricts the ability of the Poa annua to pioneer the sward, by not giving it the advantage of being out of regulation whilst the perennial species are still being regulated. Its effect on seed head development reduces the impact on presentation and performance.
Ensuring nutritional inputs are managed prudently this month will be a key factor in how quickly surface quality can be achieved. The stress inducing environment mentioned earlier, underpinned by existing fertiliser applications, means that growth can be rapid with a detrimental effect if it’s not monitored. Many will switch from granular applications to liquid products, which can be applied little and often to give a regular, balanced amount of nutrient inputs, which can help to mitigate stresses and provide even growth. The use of surfactants, where possible, will ensure that moisture is distributed evenly through the soil which, in turn, improves plant health via better rooting and nutrient uptake. Added into this can be the use of biostimulants, such as seaweed and amino acids, which again will mitigate any stresses present.
An increasing problem at varying points of the year is managing pest populations. There have been numerous reports of leatherjacket damage outside of the “typical” peak season. There is no registered chemical control for this pest to be applied at this time of year; however, if damage is significant, it may be worth considering a spring application of nematodes to try combat the problem. Steinernema feltiae can be used at soil temperatures above 8°C and Steinernema carpocapsae above 13°C, therefore it’s important to choose the right treatment for your site at this time of year. The emergency approval has just been granted for the use of Acelepryn on chafer grubs in 2021, and this will be available to purchase from May. Installation of pheromone traps allows you to monitor which species you have and to plan accordingly; it also means you can track the peak flight period to time your product application for best results.
It has been an incredibly challenging winter and pre-season, but finally, it looks like there is good growing weather to work with. Let’s hope so!
- Keep machines overhauled and clean.
- Inspect and repair any watering or irrigation systems.
- Continue to check and service your floodlighting systems.
- Replace any worn tines on your aeration equipment.