May Maintenance

UK growth reaches it’s peak, for the next eight weeks or so, so emphasis should be put on mowing frequency as long as there is sufficient moisture:

  • Apply 'little and often' foliar feed, consisting of mainly Nitrogen, with other nutrients and ingredients, such as Potassium.
  • Continue to seed sparse or bare areas.

You should be mowing at least three times a week, with brushing, grooming or verti-cutting on a weekly basis. This will improve air movement and reduce thatch levels.

Sward height should be maintained at around 4-5mm.

Using a mix of micro, needle or star tines aeration should continue. Soil compaction will be reduced with the use of micro tines, paired with the regular use of a sarrel roller.

During May, you will find soil and air temperatures tend to increase, meaning irrigation becomes important. If sandy soils, or soil profiles in general, are allowed to dry out they often become water repellent, which then become difficult to re-wet. You will need to spend more time hand watering the problem areas, which tend to be high spots on the green.

When you do water, ensure you go to a depth of 100-150mm to encourage the roots to go down to find the water.

The cold night-time temperatures have resulted in a slow spring and sluggish growth. On surfaces requiring an injection of growth a nitrogen source such nitrate or ammonium will be readily available to the plant.

Something such as Advanced Generate 12-3-9 +2Mg +2Fe has the benefit of the whole 12% nitrogen source being ammonium which is readily available to the plant in cooler conditions. It also contains a big hit of sulphate at 34% which is an essential element for plant metabolism and amino acid production in the spring.

On top of that, it also contains magnesium and iron, which will increase chlorophyll production to maximise the efficiency of photosynthesis as well as harden the leaf cell walls against disease and cold weather stress.


A key skill that should be adopted by all Groundsman/Greenkeepers is monitoring the performance of your playing surface. With the aid of modern technology such as cameras you can now monitor the performance and the condition of your sward in many ways.

For many years the turf industry has promoted the use of Performance Quality Standards (PQS) to ascertain the standard of sport pitch maintenance.

It’s also important to measure the performance of your facilities to ensure it meets any stated guidelines by the sports governing bodies.

This can include measuring sward height, soil temperature, weed content, levels over a 3m level, composition of grass species, hardness and infiltration rates of the soil root zone.

We have seen the development of GPS mapping in recent years, that can measure chlorophyll, moisture content and deviation in levels. Soil test will also help determine soil type, organic matter content, CEC capacity, nutrient status of the soil and soil pH.

Keeping a record of these parameters will help you have a better understanding of what is going on within your playing surface and enable you to make better decisions on what maintenance inputs you will need to undertake to maintain surface playability.

Weeds, Pests & Diseases

Merit can still be applied, as leather jackets and chafers are fairly prevalent, but it can be tricky to get a good kill when the grubs are at this stage of development.

There may be some symptoms of plant parasitic nematode activity, as soils warm up. There are two different types of nematode which infect grass plants; Endoparasitic which enter the roots tissue and feed on the plants or Ectoparasitic which migrate along the outside of the roots and feed on root cells.

Be on the look-out for the following symptoms:

  • Yellowing and thinning of the turf
  • Reduced turf vigour
  • Premature wilt
  • Turfgrass that is slow to recover from stress
  • Turfgrass that does not respond to fertilisation

You can assist in returning some balance to the soil with Biomass Sugar, which will reduce plant stress associated with parasitic nematode attack.

If the warmth occurs in conjunction with humidity and moisture on the leaf for prolonged periods Microdochium patch may also pop up as temperatures increase. If grass is growing well the disease may well just bubble under the surface and the grass will outgrow it.