May Maintenance

Key tasks this month

If the weather is good enough (and that could be a big if), now is the time to get mowing and reduce the height of cut on your greens. By the end of the month they should be at their summer height of 3.5mm to 6mm.

Other tasks to back up this important work is thatch and side shoot growth removal using grooming and verticutting units. Groom every fortnight and verticut once a month.

How often you mow will vary depending on the grass growth rate and the standards set by the course manager but it will likely be between two or three times per week. Your mowing heights can also vary depending on local conditions, type of course, course expectations, sward type and mower type.

Use the mowing heights here as a guide and remember to never remove more than a third of total grass height in each cut. Place as little stress as possible on grass now and reap the benefits later in the season.

  • Greens: Maintain around 3.5-6mm
  • Tees: Maintain around 10-15mm
  • Fairways: Maintain around 15-20mm
  • Rough/semi-rough grass areas: Mow and tidy these areas

Regularly change hole positions and again how regularly you can do this will depend on a number of factors: green sizes, construction, tournaments, amount of play and green condition. When it is wet, the hole will wear more quickly than usual, which can result in a crowning effect and surface wear. This wear will be all the more apparent if the green has thatch problems. Holes can tend to wear and form a depression caused by the placement of golfers' feet. Most course will be changing their hole positions three times a week or more.

Maintain surface levels using light topdressings of sand/rootzones - stick to the matra of 'little and often'. Continue to aerate and vary your use of micro, needle and star tines for maximum effect and minimal surface disturbance. Sarrel rollers are an option and your objective here is always to 'vent' the rootzone and allow water to move quickly from the surface into the rootzone and encourage the turf to root deeper.

On a daily basis, inspect, weed and rake your bunkers, inspect greens, tees, flags and hole positions for any damage or vandalism. Also inspect tee boxes, pegs and competition markers every day before cleaning and moving to new positions as required. Machinery needs to be checked and cleaned daily  and any repairs serviced and carried out accordingly.

On a weekly basis, inspect all water features on the course and clean out any debris or litter. Each week, mark out trolley areas, out of bound site areas and range markings.

When conditions allow, seed bare and worn areas of greens, tees and fairways, as the rise in temperatures help germination. Germination sheets can help you here but remember to remove them regularly and check for any signs of disease. Without good soil to seed contact this is a waste of time. Use new seed as old seed might not be as effective. Bear in mind that bents and fescue grasses need higher soil termperatures to germinate successfully.

As and when required, topdress greens and tees, always making sure you have enough topdressing material for any renovation you are still carrying out this month.

Similarly, apply wetting agents as and when you need to and they will generally be applied on a monthly basis during the season.

Trees and woodland areas will need to be checked as high winds can damage trees. Inspect and repair or even remove damaged trees and inspect them regularly so the course passes any health and safety requirements e.g. golfers not being hit by any tree debris.

Once a month, estimate and order seed, loams and fertilisers, fuels and other consumables.


A key skill for all groundcare professionals is effective monitoring of the performance of your course. Advances in technology have helped greatly with new tools available as well as cameras to monitor the condition and performance of your sward in many ways.

Performance Quality Standards (PQS) have been promoted by the turf industry for several years and they are benchmarks for sport pitch maintenance standards.

Use everything at your disposal to measure the performance of your course to make sure it meets the standards you are being guided by such as governing bodies of the sport.

Performance measurements can include measuring the height of the sward, grass species composition, soil temperature, weed content, levels over a 3m level, hardness and infiltration rates (porosity) of the soil rootzone.

GPS mapping devices are now available that measure chlorophyll, moisture content and deviation in levels. Soil tests will also help you determine soil type, nutrient status of the soil, organic matter content, CEC capacity and soil pH.

Keep a record of your measurements and tests so you have as good an understanding as you possible can about what is going on within your playing surface, as well as helping you make good decisions on how to keep it in prime condition.


Cold night-time temperatures have ushered in a slow spring with the result that growth has been slow. Where you have surfaces that need a boost, use a nitrogen source such as nitrate or ammonium to get to the plant. Something like an Advanced Generate 12-3-9 +2Mg +2Fe gives you the benefit of the whole 12% nitrogen source being ammonium which in cooler conditions is readily available to the plant. It also contains some 34% sulphate which is a big hit and an essential element for plant metabolism and amino acid production in the spring.

Plus, it also contains magnesium and iron which help increase chlorophyll production to maximise photosynthesis efficiency and harden the leaf cells so they stand up against disease and cold weather stress.

If you have a higher end facility and are looking for more control, then try soluble fertilisers like Maxwell SolControl 24-8-12 and 26-0-26 or liquids like Green Solutions 15-0-6 and 18-9-9 which allow for finer control of application rates and frequency. The SolControl products both contain nitrates which is very plant available in cool conditions.

Weeds, pests and diseases

Leatherjackets and chafers are especially prevalent currently and although you can still apply Merit (if you have some in stock) it can be hard to get a good kill when the grubs are at this stage of development.

As the temperature and the soil warms up you may spot symptoms of plant parasitic nematode activity. Two categories of nematode infect grass plants - Ectoparasitic and Endoparasitic. Ectoparasitic nematodes migrate along the outside of roots and feed on root cells while Endoparasitic nematodes enter the root tissue and feed there.

Spotting any of the following symptoms should set alarm bells ringing: yellowing and thinning of the turf, reduced turf vigour, premature wilt, turfgrass slow to recover from stress, turfgrass slow to respond to fertilisation.

You can use BioMass Sugar as an aid to returning balance to the soil and reducing plant stress associated with parasitic nematode attack.

And as temperatures continue to increase, keep an eye out for Microdochium patch, especially if the high temperatures are combined with prolonged humidity and any moisture on the leaf. Only use systematic fungicides as a last resort as in any case, if the grass is growing well, the disease could just bubble under the surface and the grass will outgrow it.


Your priority now is keeping machinery up and runing and in good working order. A good wash down facility is essential for keeping equipment clean and making sure it complies with the latest legislation.

If you are lucky enough to have your own mechanic at your club, then you are at an advantage as this will keep any downtime due to repairs at a minimum.

Dennis Mowers