Bowling Green Digest: Spring 2025 | Part 1

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Hopefully, your green has overwintered well, and your focus is now shifting towards the spring preparations. Our objective for the winter was to minimise any turf decline so that we don’t come into spring with a major recovery job on our hands!

Some level of deterioration will have been inevitable, but if the winter programme was followed, then the green should be in a reasonable condition, with full grass cover and minimal moss encroachment or disease scarring.

During March, April, and May, our aim is to transition the surface, as conditions allow, to reach its summer best.

And because there is a lot to think about during this time, we felt it best to split up spring into 2 parts with this edition covering early spring (March – April) and the next one following on with the run up to summer (April – May).

The first problem with spring

The start of the season can be particularly challenging for greenkeepers because League fixtures typically begin in April, well before the turf has fully kicked into growth.

Pre-season practice often starts in March, which means that the greens are put into use before they’re strong enough to withstand the pressure of maintenance and play.

This creates a tough scenario for greenkeepers, who must balance the demands for early play with the need for careful turf management to avoid lasting damage.

Running on empty

What many non-turf professionals don’t realise is that, on average, turf operates at less than 5% of its optimal growth potential in March, and under 10% in April.

During cold snaps, it can even drop to 0%. Understanding these limitations is crucial—spring growth is often far more restricted than people realise. Because of this, our maintenance approach needs to be adjusted accordingly, rather than being driven by player expectations.

Overdoing early-season preparations can lead to damage that’s hard to recover from, potentially impacting the surface for the rest of the season. It’s important to ease into early spring maintenance, avoiding aggressive tactics like low mowing heights before good growing conditions have properly kicked in.

Manage player expectations

Given these early challenges, it’s crucial to manage player expectations and communicate why a cautious approach is needed for early-season maintenance and play.

While players are eager to get back on the green, it’s important for them to understand that conditions won’t yet be at summer levels. A period of recovery and refinement is necessary, and that recovery is governed by growth.

Moss Invasion

One of our early challenges in March and April is moss ingress. The cool, potentially damp conditions are ideal for moss growth, while the turf remains weak and vulnerable to invasion.

Moss can spread quickly at this time, smothering the sward and affecting surface consistency.

To help counteract moss ingress, we tend to use products containing Sulphate of Iron.

This can be applied as a stand-alone spray or as a component part of a pre-season granular fertiliser application. Sportsmaster WSF Iron can be sprayed at a rate of 3kg per 1000m² dissolved in 60 litres of water.

Granular products like the Greenmaster Pro-Lite “Invigorator” (4-0-8 + 4Fe) or Greenmaster Pro-Lite “Invigorator Plus” (4-0-14 + 8Fe) can be applied at 25-35g/m² using a suitable fertiliser spreader.

These products help tip the balance back in favour of the turf.

So it’s all about growth

In a nutshell, the early preparation and refinement of our bowling surfaces relies on growth.

Turf growth dictates the grass’s ability to withstand and recover from both maintenance and play. It’s what allows us to build a fine, dense, healthy, and deep-rooted sward that can support play whilst also resisting weed, pest, and disease pressure.

As greenkeepers, we aim to manipulate growth levels with specialist fertilisers to support our goals. Turf nutrition is all about finding the right balance—too much growth can result in a lush, slow, and disease-prone surface, while too little growth can lead to uneven surfaces due to thinning, or the development of diseases linked to turf weakness.

Striking that balance is the key to maintaining a healthy, resilient playing surface.

But spring is never straightforward

Contrary to popular belief, spring doesn’t magically arrive overnight to fix everything. In March and April, turf growth will be weak and inconsistent at best, coming in brief, short-lived “waves” as temperatures and light conditions fluctuate.

While there may be occasional windows of favourable growing conditions, these are often followed by cooler spells that put the brakes on development.

Spring is very much a “stop-start” season, which can be frustrating for greenkeepers eager to get on with things. Consistent, sustained growth generally doesn’t kick in until late May or early June.

In the meantime, we need to make the most of whatever conditions we are given.

And so, we use our wiles

With Spring generally being against us, we need to try to maximise any opportunities that might come our way.

Essentially, we need to take advantage of those early fleeting growth opportunities. We do this by applying a fertiliser to amplify any available growth to help fill out and strengthen the sward and allow us to proceed with some surface refinements.

To do this we need to closely monitor the forecasted growing conditions and be ready to act when the chances arrive.

Keeping an eye on growth

Monitoring for growth opportunities can be incredibly helpful for the timing of your spring fertiliser applications.

The free Turf Advisor app from Syngenta offers several useful climatic metrics and turf models, including one for cool-season Growth Potential (GP). GP is expressed as a percentage of optimal turf growing conditions, and as a general rule, GP needs to be consistently above 40% for conditions to be able to produce meaningful growth.

Below this threshold, turf growth remains too slow for effective recovery, which means that intensive maintenance practices like scarification and close mowing could cause lasting damage.

By regularly tracking GP forecasts, you can optimise your pre-emptive fertiliser applications and adjust your maintenance intensity accordingly, ensuring you don’t overdo it when growth is insufficient.

Taking your chances

Spring fertiliser applications are the key to amplifying and prolonging the turf’s response to those intermittent and short-lived “waves” of spring growth.

They help us to make the most of the chances we get. Granular fertilisers are typically applied before opening the green, ensuring that nutrients, particularly nitrogen, are available to stimulate growth when conditions allow. Some examples of common early spring fertilisers include:

• Greenmaster Pro-Lite “Invigorator” (4-0-8 + 4Fe) applied at 25-35g/m²
• Greenmaster Pro-Lite “Invigorator Plus” (4-0-14 + 8Fe) applied at 25-35g/m² (if additional iron is needed)

These products help us take advantage of available growth opportunities. However, once the green is in play, there’s a risk of the fertiliser granules being picked up by the woods, so we tend to only apply granular fertiliser during the bowling season when there’s a sufficient gap in play to allow for proper granule dispersal.

During the playing season, we primarily rely on liquid fertilisers because they are less disruptive and easier to apply without impacting on play.

The need for seed

If your surface has been scarred by disease or has lost grass coverage due to issues like shading or winter play, some localised overseeding may be required.

The success of any seeding in early spring will be limited by the poor conditions for germination and establishment and the level of maintenance and play.

It’s generally best to use a high-quality bent/fescue seed mix for this, as these species are well-suited to bowling greens. The seed should be worked into the surface carefully and protected from damage caused by maintenance or play.

These areas will need time to establish before they can tolerate mowing or foot traffic. For isolated patches of scarring, a “turf doctor” type patching device can be used. This allows you to swap out damaged areas with healthier turf from the edge of the green.

Keep spiking

By early spring, any deep tine soil management work should have already been completed to avoid disrupting the surface as the playing season begins.

Ongoing undisruptive solid/micro-solid tining is recommended to keep the upper soil profile aerated and maintain an open surface for effective water infiltration.

This approach supports healthy root function, improves moisture movement, and helps maintain a consistent, true playing surface.

Slit tining should be avoided in spring, as the slits can open up during dry periods, leading to an uneven surface. It’s important to balance aeration with surface integrity, ensuring that the turf stays healthy and stable but without compromising its playability.

Beware of pests and diseases

Wormcasts can disrupt the bowling surface, affecting playability and bring up weed seeds to establish from the soil seed bank. To minimise this disruption, worm casts should be regularly scattered using a switching cane, especially before mowing, brushing or matches.

This helps to smooth out the surface and prevent the casts from causing unevenness during play.

Turf disease pressure is generally low at this time, but prolonged mild and damp conditions can promote the development of Microdochium patch, leading to scarring and an uneven playing surface.

Good cultural practices can help suppress disease activity. Regular dew brushing to reduce surface moisture, occasional applications of iron sulphate, and balanced nutrition all play a part in discouraging the development of disease. If a fungicide is required, the choice should be based on current weather conditions and disease severity.

Always seek advice from BASIS-qualified turf advisors to ensure appropriate treatment options.

A gradual transition

During March and April, the development of the green will be dependent on growing conditions and so can be painfully slow.

With the emergence of some growth, we can gradually increase maintenance intensity to begin refining and perfecting the playing surface. The ultimate goal is to create a consistently firm, smooth, true, and fast surface that allows the bowls to run freely and players to fully express their abilities.

Our early spring surface preparations might include:

• Staying off when frosty.
• Dew brush to remove surface moisture whenever required.
• Apply a granular fertiliser to amplify the turf response to forecasted growth opportunities.
• Initially only mow the green when growth requires.
• Lightly brush prior to mowing to lift grass blades and promote the development of a dense and upright sward and optimise ball roll consistency.
• Increase mowing frequency with growth to enhance sward refinement, improve surface smoothness, and maintain uniformity.
• Gradually lowering the cutting height in gradual increments as growth improves during the spring. We should slowly move from the winter level (6-7mm) down to maybe 5mm during April, conditions allowing.  A prism gauge can help determine the actual cutting height, rather than relying solely on the bench setting, which can be misleading.
• Consider light verticutting/grooming if growth is establishing to refine the sward and smooth out the surface, but only if necessary. Even light verticutting/grooming is a damaging operation that can set the development of the surface back in poor growing conditions.

Striking the right balance is always the key and this is especially so in early spring.

Overly intensive early season maintenance can stress the turf to cause surface deterioration if growing conditions aren’t strong enough to generate recovery.

Taking a flexible approach with carefully judged mowing heights, brushing frequency and nutritional inputs based on the prevailing conditions, will ensure a smooth transition through the early part of spring while  safeguarding turf health and surface quality.

As conditions improve later in the spring we can intensify further and focus on perfection. At this stage it is important to stay patient and carefully navigate your way through.

Guidance Note: Equipment and Professional Product Applications

Effective greenkeeping depends on using the right equipment and professional product applications.

Essential tools like well-maintained mowers, sprayers, spreaders, switches, brushes, and aeration equipment are crucial for maintaining turf quality and consistency.

Regular servicing and calibration of these tools ensure accuracy and precision in all maintenance tasks. It’s also vital that all operatives are properly trained in the use of greenkeeping equipment. Training opportunities are available through organizations like the Greenkeepers’ Training Committee, GMA, Lantra and Bowls England, ensuring that operatives have the skills and knowledge to use equipment safely and effectively.

Professional plant protection products should only be applied by trained and certified operatives to ensure safety, legal compliance, and the effectiveness of the products, while also safeguarding the environment.

Proper handling, application, and storage are essential, and operatives must hold recognised certificates of competence, available through organisations like City & Guilds and Lantra. Safety protocols, including the use of appropriate Personal Protective Equipment (PPE), must always be followed.

Additionally, storage facilities must meet required standards, such as bunded floors, to contain any spills and ensure safe storage.