The plant available water in bowling greens is determined by the physical characteristics of the soil. Most importantly the soil texture dictates the relative percentages of Macro, Meso and Micro pore space in the soil. This soil porosity also dictates the rate at which the green will drain. The balance between drainage and plant available water is one of the most critical components of a performance bowling green maintenance program. Here then is the very crux of all those arguments about top-dressing!
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:
- 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
- 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:
- Around 25mm per week.
- 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.
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 common question is “How much does it cost to water a bowling green for a season?”
Answer: a lot less for a performance bowling green than one in the throes of a traditional maintenance program.
It surprises me that clubs are surprised at the little surprises they get when the water bill comes in.
How can you be surprised that you used more water this year when you added 5 or 10 tonnes of sand to the green last autumn?
Many greens are already unmanageable in a normal (UK) summer due to excessive water requirements, localised dry patch and impermeable thatch; in a drought scenario its unlikely that there is any amount of water that would suffice.
This is because most of the water applied to poorly maintained greens is wasted to evaporation, run off and/or leaching.
Thick thatch holds water at the surface like a sponge, until of course LDP sets in, then it becomes akin to concrete and most water is lost to run off.
LDP causes soil particles to become hydrophobic, shedding any water that gets through the thatch to the macro-pores in the soil and away to the drains.
Performance greens can be watered cheaply and effectively because they only need enough to keep them alive during prolonged dry periods and can mostly take care of themselves in the normal course of a British Summer.
In many cases there is no need for anything more sophisticated than a large holding tank (the bigger the better) a simple pump and a 19mm hose to hand water hot spots on the green. This is much more effective than pop up sprinklers.
Water requirements and routines are given in more detail here.
Bowling green irrigation is one of the areas of bowling green maintenance that raises the most questions.
On the face of it, this appears to be a simple subject; install sprinklers (watering systems), switch them on when it’s dry and the green gets evenly watered and everybody’s happy!
In reality it is a minefield of decisions including; best system design for your green, water storage, watering schedules, when, how and how much to water, green speed, disease, dry patch, thatch etc.
I have assembled some more in-depth information regarding the watering of bowling greens here.
If you need any help with this subject please feel free to drop me a line directly.
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
Yes I’ve come over all Latin today; and no, it’s not because I can’t believe my old jeep sailed through its MOT yet again last week!
Even the garage owner was amazed that he couldn’t find anything wrong with it.
He sent me off with “I’ll get you next year!”
No, the Latin was inspired by a photo I received from a regular reader who sent it in to illustrate a problem he had on his green with red-thread.
However, the reason for this post is not to discuss Latin, or Red-Thread for that matter.
The clump of grass in the centre of the photo is annual meadow grass, or Poa annua to use its botanic name.
It’s not that we greenkeepers are more cultured than the average man in the street, more to do with college lecturers who insisted that we learned to identify and remember the botanic names for hundreds of grasses, trees, shrubs and weeds.
Incidentally this came in useful when I was leaving the MOT station, as I casually threw in a final, killer comment of “you need to get your Tarixicum officianale (dandelion) sprayed before it takes over the yard!”
Back to the clump of meadow grass.
This is actually a weed ( an unwanted plant in its current state and location) as we are really trying to create and maintain a sward of finer fescue and bent grasses for the best bowling surfaces.
Unfortunately, almost (probably all) all of the bowling greens in the UK will be infested with this grass.
Even newly built greens constructed on sterile rootzone material will show signs of this weed within 2 years as its seed blows in from the surrounding area.
From the picture you can see it at its worst aesthetically, which it usually is at this time of year. Right through May and June it will show up as unsightly clumps of lime green grass which contrasts vividly with the other darker green species.
Also at this time it will be seeding like mad.
The visual problem recedes as the summer progresses, but it does actually produce seed all year round.
Scarifying, verti-cutting and close mowing are of minimal value in removing the seed heads and to some extent can actually help annual meadow grass to thrive in the summer.
This is because it has a very low and prostrate growth habit which keeps the majority of the plant including seed heads below the cutting blades.
Excessive scarification and verti-cutting can actually weaken the finer fescue grass leaving the annual meadow grass with a stronger chance of survival.
It does have one Achilles heel and that is water.
Poa annua is a very shallow rooting grass and the Performance Greens program is designed to allow greenkeepers to keep the surface of their greens a little drier than most, thus putting the weed grass under pressure.
This is achieved by managing irrigation to ensure that the green is watered deeply, but irregularly which also has the effect of encouraging deeper rooting of the finer, desirable grasses.
The program also calls for a more sensible approach to cutting heights, whilst using other methods to achieve green speed. This allows the finer grasses to put down even deeper roots and also strengthens plants against drought and wear.
Poa annua is however likely to be with us ad infinitum as it is a very adaptable grass.
This adaptability is actually a good thing in the end as over time the grass becomes finer and blends in more readily with the finer grasses.
It is perfectly feasible still, however, to have a green that is predominantly fine and to keep Poa annua under control over the long term by following a sensible program that encourages the development of a healthy living soil which in turn will support a strong and dense sward of finer grass.
Localised Dry Patch (LDP) is a condition that causes turf to become hydrophobic (water repellent).
Once LDP has taken hold, irrigation simply causes the unaffected areas to get lusher while the LDP affected areas get drier. This exacerbates the problem making the green increasingly frustrating to play on.
Soil sampling will reveal powder dry soil. Unsightly brown patches of turf start to spread over most of the green. The turf on these areas recedes causing a bumpy surface and in most cases the weakened grass will be taken over by moss. But what can be done to cure the problem?
Research shows that fungi can contribute to the onset of this problem. Fungal mycelium may coat individual soil particles making it impossible for water to adhere to them.
Thatch control and irrigation management are the two most critical factors in the management of this problem.
By the time the problem is visually evident it is already too late to achieve an effective cure. This is because the problem is inherent in the green and usually only becomes visible at the height of the season.
Irrigation management requires an understanding of Water Balance in the soil and this is detailed in Performance Bowling Greens. Just look at the infra-red thermographic image on the left, it shows an infrared image of a bowling green. The red areas show the extra heat that is being kicked out by the LDP affected areas, and that is directly related to the lack of moisture retained in the soil in these areas. In the standard photo, the LDP is barely noticeable at this stage, but will get steadily worse.
Frequently we are now seeing that areas affected by dry patch disorders have suffered a complete depletion of moisture and that the soil structure has failed, turning to powder. Traditional wetting agents have sought to address dry patch from a very limited viewpoint, namely the reduction of water surface tension making it easier for water to be attracted and held around individual soil particles.
Although Wetting Agents can be used to good effect on LDP once dry patch has progressed to what we call breaking point, no amount of simple surfactant wetting agent will help it re-wet sufficiently to ensure a full recovery of the turf with full grass cover. Typically the manager has to wait for the turf to over-winter before full grass cover is returned.
This makes it all the more critical that we ensure that the products we use are effective in both results and cost.
As LDP is a disorder within the soil it is important to keep one eye on re-wetting and one on re-building the soil’s health. This can best be achieved by ensuring that you use a wetting agent product which can supply carbohydrates to the soil in addition to their soil re-wetting properties. The addition of a high volume of Carbohydrates ensures that the products also contribute to the maintenance of soil structure while helping stressed grass plants hang on to life for longer while the soil is re-wetting.
Excessive use of sand on bowling greens over the years has been the single biggest influence on the occurrence of LDP.
More on the causes and management of LDP here.
- Mowing too close
- Mowing with dull blades
- Mower set incorrectly
- Over fertilising
- Over watering
- Too little aeration
- Aerating deeper than 8 inches
- Not mowing frequently enough
- Putting the green “to bed” in autumn
- Continually treating symptoms and ignoring causes
Green Speed; the actual surface pace that we can reasonably expect from the green on a regular basis.
Consistency; the ability of the green to replicate high performance throughout the day, week and season and also from season to season.
Predictability; the ability of the green and individual rinks to be set up for play of a reasonably predictable nature, time after time and over time.
Achievability; high performance must be not only physically achievable but also relatively easily achievable and for that the program we put in place must tick the following boxes; it must be:
Workable; with “in-house” labour and skills or with a financially sustainable amount of “bought in” labour and skills.
Sustainable in terms of its environmental, financial and infrastructural requirements.
Replicable time after time within the parameters defined above.
Minimum Input in terms of artificial fertilisers, chemicals and expensive bought in machinery or skills.
The goals we have set above require us to produce a very specific kind of green surface.