During dry and hot weather the need to water your green properly can’t be over emphasised. Although it can be tempting to let the green burn to achieve speed, this can turn to disaster and cause the green to fail later in the season.
So what is the right way to water your green?
Whatever method of watering you are using, whether it be an automatic pop up system, hose and sprinkler or simply hand watering with a hose, the rule you should follow is “deeply not daily”. It is better to give the green a really heavy watering twice or three times a week, than it is to water lightly every night.
Light applications usually don’t address the need to get water deeper into the rootzone; more of the water is lost to evaporation and if too light, might not even penetrate the surface.
How much to apply?
Again as a general rule, in the UK during a rainless week the average green will lose about 25mm of water to evaporation and plant transpiration combined; this will be significantly higher during periods of extreme heat. This means that you should aim to replace at least 25mm through irrigation over the week. Of course you can subtract any significant rainfall the green receives from that figure. A simple rain gauge can help a lot here.
How many minutes of sprinkler time is that?
Most automatic irrigation systems on UK greens are of inadequate design to deliver the required amount of water evenly across the entire green. The centre of the green usually does not receive enough water and you should make sure that additional water is applied in the centre by hose. The typical 4 sprinkler bowling green system is also hampered in its performance by a lack of tank capacity, with long waits between applications for tank filling.
However, with all of these problems put aside, the average automatic system will deliver 1mm of water for every 2 minutes of run time. To deliver our 25mm requirement in a week, this would mean running each sprinkler for 50 minutes per week.
The danger in relying too heavily on automatic systems is that although they apply the water evenly across most of the green surface, they do tend to under water the centre of the green. Another factor to consider is the fact that greens don’t dry out evenly and some areas will usually need more water than others and that brings us to Localised Dry Patch.
How to address hot spots and dry patches.
Localised Dry Patch (LDP) is a real problem on greens throughout the UK. This is a disorder that results in random areas of the green surface being unable to take in water, in other words they become hydrophobic or water repellent. These areas must be treated differently:
First of all you must open the surface to allow water to penetrate into the turf. This can be achieved by hand tiner or a sarrell roller. It is then essential to hand water at high volume, preferably using a 19mm hose connected to the irrigation system. Additional benefits can be gained by applying a wetting agent alongside or prior to watering. Dry patches need to be watered by hand regularly with time given between soakings to allow the water to penetrate the soil.
Hi Paul
a very important question and one which will be asked a lot this year I would imagine.
I’ve moved it over to the greenkeeping forum to make sure members get a chance for input. You can find the thread here:
https://bowls-central.co.uk/groups/greenkeeping/forum/topic/bowling-green-irrigation-and-hosepipe-bans-from-paul/
John
Hi John,
I will be honest, the calculations for the amount of irrigation needed in ‘Performance Bowling Greens’ are a bit complicated. I was wondering if I invested in a moisture meter, and knew the root depth and soil type, would there be a general guide to what moisture level would be ideal for a bowling green? Certain areas of a green may need more than others (e.g. dry spot) and when hand watering (my preferred application method) such a moisture test would be a great guide to how much to apply. Also, when working towards a high bent/fescue sward, would this moisture reading be lower than if someone was happy with a poa green? One of your fact sheets about how to gauge how much water to apply would be really useful! Thanks.
Robert
Keeping a water balance sheet is still the best way to accurately measure irrigation requirements and minimise water bills. It can be a little tricky to set up, but it’s fairly straight forward to maintain once you are under way.
By using this method you can easily gauge the amount of Soil Moisture Deficit (SMD) you want to introduce for the reasons you’ve specified; encouraging deeper rooting of fine grasses and discouraging shallow rooting species like Poa annua.
Of course, if we get a summer like last year this is all fairly pointless as it will be impossible to maintain a deficit when nature decides the green will be kept at field capacity.
Hand watering is good, especially for dry patch affected areas like you say.
This article gives a bit more info on irrigation amounts etc.
Would be good to know how you get on with the moisture meter.
I’ll get round to doing a fact sheet on irrigation soon.
Good to hear from you
John
my club have a automatic system and have been using for 2 weeks maybe 3 weeks without turning it off so I gets watered every night for 15 minutes a sprinkler (4 pop ups) so 1 hour a night and the green has gone from being a running green to a heavy sponge like green what would you advise to get a happy medium.
Jono
Thank you for your query.
Sprinkler timings are very much dependent on the prevailing conditions and the water requirements of the green.
Sprinkler systems also vary, but after researching most of the big manufacturer’s systems, a typical bowling green layout such as yours will deliver 1mm of irrigation for every 2 minutes of run time. Based on this you are currently applying approximately 50mm per week (we only calculate the per head time and not the combined time of the 4 heads). In a normal dry week the average green might lose 25mm to evapotranspiration and it is this amount we would usually look to replace, typically by running the system for 16-18 minutes(per-head) on 3 nights of the week.
Evaoptranspiration rates will be greater when the weather is hot like it was this summer so allowance should be made for that.
Thatch levels, compaction, grass species and a host of other factors will be at play here also, so it’s not easy for me to make a precise judgement on your particular situation; but the details above are typical/average.
I recommend using a Water Balance Sheet for irrigation management as this allows you to accurately control inputs based on actual need and also allows you to maintain a slight Soil Moisture Deficit in order to encourage deep rooting and finer grasses.
More information in this article
Let me know how it goes.
John Quinn
thanks for your response. just a couple of things really I have set up a program to water 3 days at 10 minutes per head so that’s just been set up and what was concerning about heavy watering was the green was sweating during sunny periods and the surface was always wet and the ground being to soft was leaving foot prints when people walked. A bowling green is a thing of nature and applying unnatural water can do more damage than good I have seen other greens become unplayable due to watering systems being introduced they are a bowlers nightmare and the best clubs in many areas don’t use them to achieve their best results. A running green is the only way to play bowls.
You are leaning against an open door here Jono. More isn’t usually better.
However, a very large proportion of UK greens are not in good health and would not stand up well to zero irrigation, especially in a summer like this one. That’s due to underlying problems caused by decades of inappropriate maintenance; in particular routine heavy top dressings with high sand content and a reliance on symptoms management as opposed to managing for a healthy soil and turf relationship.
Your previous watering regime was double what most greens need even in a dry period, so the adjustments should make a big difference.
The Water Balance Sheet method of irrigation management is a good way to maintain a healthy soil moisture deficit (slightly under watered).
John
Hi I have been informed that contiued use of household water on our bowling green. Can in courage dicease and moss.
Is there an additive that we can add to our tank ?
Hi I water my bowls green for now more than 5 minutes per head 3 times a night and some of the time not at all due to only having 4 pop up heads around the green and only having 2 tanks that need about 1.1/2 hours to fill up. Should I spike the green deeper than a sorrel roller,i.e.a pencil Tyne more often than once a month.
Hi Alan
Yes that will certainly help with water penetration on areas affected by Localised Dry Patch. You could also use a wetting agent such as Hydroaid to help with water penetration or Incision to aid water retention in LDP affected areas.
John
we purchased an irregation system that involves pulling out a hose with a sprinkler on the end, the water is delivered via a pump which slowly coils the hose in and pulls the sprinkler accross the green.
it takes two runs to cover the whole green and so far has been successful.
Have you heard of this system and if so is it ok.
Hi Terry
It sounds OK to me. Do you know what the output is per pass?
Regards
John
Hi John
What is your advice regarding timing of irrigation. Currently I irrigate at 02.00, 03.00 and 04.00 twice a week with the period of irrigation varying depending on the prevailing weather but am being asked to start irrigation earlier so that the soil remains moist for longer(?). However, my concern is that it would encourage rot and fungal growth due to extended contact which is, after all, the main reason why the grass is swept of dew in the morning.
Hi Graham
Dew removal to reduce disease risk is really a feature of autumn maintenance when the green isn’t being maintained quite so often, or when the green is otherwise very dry to ensure the dew is returned to the soil to make the most of available moisture.
In hot, dry weather in summer, the best time to water is at night, taking into account the guidance in this article.
Regards
John