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Watering Bowls Greens-the least you need to know

irrigation management is critical but straight forward

The recent hot and dry weather has seen the UK experience forest fires for the first time in a lot of years.

It’s a hot dry spring, just the thing to get the bowlers out and active early in the season.

But, of course with this comes a problem. How do you get a green that has just come through one of the most prolonged and cold winters on record to perform well when the underlying soil is powder dry?

Performance turf requires heat and moisture and it is inevitable that you will have to turn to your irrigation system at this time to keep your green’s progress moving forward. Failure to keep up now could result in a disastrous season later on when the green dries out unevenly, succumbs to Localised Dry patch or simply doesn’t perform due to a lack of moisture early in the season.

Over the last week or so we have been inundated with readers asking for advice on the correct irrigation of bowling greens.

There are 2 key pieces of information you need to know before you can hope to keep up with the irrigation requirements of your green:

  1. How much moisture (in mm) is being lost from the green each day due to evaporation from the soil and transpiration from the grass plants? The combined effect of this is, strangely enough called Evapo-transpiration or ET
  2. How much water (in mm) does your irrigation system apply for each minute of run time?

Armed with these two pieces of information you can water your green confidently without over or under doing it.

So what are the answers to these questions?

There is a detailed article on this here.

But you’ve come here for a cheat sheet haven’t you?

For a very large proportion of bowling greens the answers are as follows:

  1. Around 25mm per week.
  2. Approximately 0.5mm per minute of run time; i.e. 1mm requires 2 minutes of run time.

These answers are based on averages; so if you are suffering blisteringly dry heat the first answer could easily be higher. If you have anything other than a standard specification, 4 pop-up sprinkler system from one of the main manufacturers such as Toro, Hunter, Rainbird etc the second answer could be a lot different, particularly if you are using a hose.

Getting irrigation right is essential to achieving a consistently high performance bowling green.

For more detailed information on the problems associated with this issue have a look at these articles.

For more in depth information on calculating your irrigation requirements and inputs have a look here.

As always any questions or comments please feel free to contribute.

Performance Basics-Watering the Green

Irrigation-a vital skill to master for a performance green

The watering of bowling greens is one of those critical issues in bowling that splits opinion across the game.

Some purists would see no artificial watering of greens regardless of how dry the weather gets. Some are in favour to different degrees; some would argue that the green should only be watered enough to keep it alive, while others demand that the green be watered heavily and often to keep it green.

For me the critical issue is as always performance.

We can argue about the right way to water or not water greens until the cows come home, but green performance is the only measure we should really be worrying about and that means we need to deal with individual greens on an individual basis.

Some greens, mainly those that haven’t been subjected to years of sandy top-dressings dry out evenly across the surface. As the weather gets drier, these greens get faster and smoother and everyone is happy. However, there is a point of no return for these greens also and a complete drought will see them go Read more

a lot of hot air?

Air is a very important component of a Performance Bowling Green.

50% of a healthy, performance green will be air; 25% Micro-pores and 25% Macro-pores.

The Macro Pore or “aeration” space is where drainage happens.

The Micro-Pore or “capillary” space is where grass plant roots get their water and nutrients.

Tip the balance in favour of one or the other of these and things start to go wrong.

Compaction reduces the Macro air space in soil and inhibits drainage and root penetration. The soil now holds on to too much moisture and a whole raft of other problems ensue; particularly the build up of excessive thatch due to the anaerobic (lacking in oxygen) soil conditions brought about by the reduction in air space.

Thatch becomes a breeding ground for fungal disease and a base for Localised Dry Patch to take hold. The thatch doesn’t break down naturally as it should because there is a massive reduction in the population of aerobic soil microbes and they usually do this job.

Tip the balance the other way by applying excessive amounts of sand top-dressing and there is now too much air space, there is very little capillary space and the green starts to dry out too quickly. Localised Dry Patch now takes over, the surface is unpredictable and the soil can’t provide the nutrition the plants need naturally any more.

Yes, for a healthy living green that performs to order you need a lot of space; 50% air space.

Luckily, a healthy living soil knows how to do all of this without us.

We are only needed to help rectify the damage we inflict, which is mainly compaction and nutrient depletion through the removal of grass clippings.

Ahh! how simple!

Localised Dry Patch Update

LDP Affected green after heavy rain

Already the relatively dry April and start to May has seen bowling greens suffering from Localised Dry Patch (LDP).

As we have discussed many times on this site before, this condition is a major problem for bowling clubs throughout the UK and if your bowling green is aready showing the tell tale signs then you need to take rapid and relentless action to avoid major disruption to your bowling green surface this season.

Meantime for greens already showing signs of the problem here is my Read more

Bowls Green Maintenance Basics-Green Speed

There are some less than obvious essentials required to achieve consistently agreeable Green Speed

The great debate about green speed has raged on since the beginning of the game. But what are the factors known to affect green speed?

In order of their impact on green speed these are the top 7 factors that you should bear in mind. Obviously there are others such as weather patterns, level of play etc, but these are largely out of the greenkeepers control and in any case do not figure highly in green speed management.

Thatch Layer Control and Management; this means knowing the thatch levels on your green and having a feel for how quickly thatch builds up at each point in the year.

Typically thatch will be much quicker to build up in the main growing season and it can easily take greenkeepers by surprise if they don’t keep a watchful eye on the situation.

Reducing a troublesome thatch layer significantly is a job best left for the autumn when severe measures can more safely be taken, but following the Performance Greens program will ensure that you are minimising the occurrence of new thatch through the production and maintenance of a healthy living rootzone and turf.

You can find more in-depth articles on thatch here.
Compaction Control and Relief; Second only to thatch in causing green problems, Compaction is a Read more

for effective Bowls Green Maintenance water Deeply not Daily!

Bowling green irrigation or watering is often mis-understood and as a result is often managed insufficiently to ensure that the green performs to its highest standards.

The first thing is to make sure of, is that you are applying enough water every week and that means trying as best you can to keep a record of any rainfall and irrigation that is going onto the green.

Making irrigation management a priority in your bowling green maintenance program is crucial because in a typical dry week your green will lose the equivalent of 25mm of moisture through evaporation from the soil and transpiration from the grass plants ; please remember that this varies considerably around the country and will depend on things like temperature, relative humidity, wind speed and direction, precipitation and of course your bowling green maintenance program.

This means that you should be aiming to get at least that amount back on.

In Performance Bowling Greens, a practical guide I go into detail about Soil Moisture Deficit and how to keep a water balance sheet for the most accurate and efficient way to manage irrigation and that is a really good method to use to get this right.

However, bowling green maintenance at the height of the summer relies a lot on feel for the soil as well and although I would always try to maintain a manageable Soil Moisture Deficit to encourage deeper rooting etc, it is more important right now to get on sufficient water to ensure your green plays consistently and to keep localised dry patch under control or hopefully at bay.

This means you should be aiming to get 25mm of water on in any dry week, making allowances for any rainfall you have had by reducing that amount accordingly.

The most common pump and sprinkler set ups for bowling green maintenance from most of the major irrigation manufacturers will put out approximately 1mm of water for each 2 minutes of system run time.

This means that you need to run the system for 2 minutes per head to replace 1mm of water lost. Remember that is “per head”.

So for a 25mm watering you need to run the system for 50 minutes per head during a 7 day period.

The most effective way to do this is to get this water on in as few applications as possible. Try to aim for 25mm over 3 nights. This is much more effective and makes much better use of precious water than 7 light applications where much of the water is lost to evaporation in the morning.

In my Bowling Green Maintenance book: Performance Greens, a practical guide I go into this subject in quite a bit of detail and lay out a plan that you can use to manage irrigation more effectively.

Getting Bowls Green Irrigation Right

Bowls clubs are often divided on whether to water the green or not. When I visit clubs to advise on this, they are generally under-watering their greens.

This results in poor surfaces, especially when a green is still within the renovation phase as described in my book Performance Bowling Greens.

You can think of Soil Moisture Deficit in much the same way as a negative balance in your bank account.

Soil Water Balance Management

…is almost unheard of within bowling circles or certainly the bowling circles I have been involved with but is a critical part of the management program to get right for high performance and deals with the management or Read more

Irrigation, how much is enough?

Irrigation, how much is enough?
irrigation management is critical but straight forward

Irrigation is on everyone’s mind at the moment, but how much is enough?

As a general rule greens lose approximately 3-4mm of moisture per dry day to evapo-transpiration, although this can vary with conditions; that’s approximately 25mm or 1 inch per week.

Again a very general rule is that many of the more popular automatic sprinkler systems will apply around 1mm of water for every 2 minutes of run time.

So again as a general rule to replace a week’s worth of losses you should be running the sprinklers for around 50 minutes in the week.

Now I will add a qualification or four to that:

  1. requirements can vary widely depending on location and conditions.
  2. don’t apply light applications on a nightly basis, try to group these into heavier and less frequent applications for best effect.
  3. try to move to a water balance sheet type system to manage irrigation more accurately…it will pay off quickly
  4. don’t rely on a typical bowling green irrigation system to apply water evenly or in sufficient volume…always check and measure what you are doing.

Irrigation management and water balance sheets in my book Performance Bowling Greens.

any questions please ask!

Localised Dry Patch still causing problems in autumn

Localised Dry Patch causing seed problems

Over-seeding of bowling greens seems like a straight-forward task; you put the seed on and the green’s bare areas recover.

However, one of our regular readers has raised an interesting question today about over-seeding and it is by no means isolated.

After over-seeding the green, the seed has taken well on the parts of the green that least needed it and nothing has happened on the barest areas of the green where the new grass is most needed!

This is unfortunately a very common problem and is usually related to our old friend Localised Dry Patch (LDP).

The barest areas of the green going into the autumn are usually the spots that have been affected by LDP and as such are bare due to lack of soil moisture.

This means that quite a lot of preparation is required before seeding and this might even include heavy watering to get the soil to hold enough moisture to get the seed off to a good start.

It might be necessary to do some light cultivation with a Sarrell roller or hand cultivator and, if the underlying soil is still dry and water repellent, a wetting agent would also help.

The main problem is that we are now a bit late for further seeding, although this largely depends on the weather and temperature. I have seeded successfully up to Christmas in the past, but success with this is obviously dependent on the remainder of the winter. Certainly if we were to get another one like last year, even early seedings will struggle to survive the winter.

If anybody is still having trouble getting grass cover on the green after overseeding please feel free to contribute ideas, tips or questions to the site.