In this article we take the soil samples you removed in Fix your bowling green Step1 and look more closely at them to discover what's going on under your green. This is one of the most valuable practices that any greenkeeper can undertake as it can reveal a wealth of information about the condition of your green that you could previously only guess at.
Towards the end of every bowling season thoughts start to turn to the autumn renovation program or the “closing of the green” as many clubs call it. Bowling clubs throughout the UK will take delivery of between 3 and 10 tonnes of very expensive top-dressing compost, which will be applied to the green after hollow tining or some other aeration operation, in the belief that this will ensure that the green is in perfect condition next season. However, too much top-dressing can actually harm the green and in many cases, clubs simply shouldn’t be doing it at all…but why?
The answer is simple yet full of complexity. At it’s most basic, the answer is that excessive use of sand on bowling greens causes the under lying soil to become inert; lacking life or the complex web of interactions that go to make healthy, high performance turf. The natural balance of the soil/turf ecosystem is upset and the green will never be capable of consistent high performance for as long as the folly of top dressing is allowed to continue.
The complexity comes in when we start to consider that top dressing is recommended by most experts and consultants and that this advice is religiously followed by the vast majority of bowling clubs. However, a brief look at the facts facing many bowling greens after decades of this type of maintenance makes it perfectly clear that top-dressing is not a good option for the majority of bowling greens in the UK.
In the remainder of the article I want to explore the issues I have experienced with greens that have been routinely top-dressed using high sand top-dressing composts over the past 30 years. I will explain the problems with Localised Dry Patch, Thatch, Soil Exchange, Green Levels and Surface Smoothness, Irrigation and water
management and the dilemma that all of this leaves many clubs facing.
So lets’ start with Localised Dry Patch or LDP.
Localised Dry Patch
Over the last 20 years Localised Dry Patch (LDP) has become a major problem on bowling greens, and although this is not wholly attributable to top-dressing, the excessive use of sand in the top-dressing mix has caused water retention problems on a lot of greens.
It is of course desirable to have a free draining soil profile on a bowling green to help to encourage deep rooting of the grasses and to maintain a reasonable green speed for play. However, continued application of bulk sandy dressings is of limited benefit to most greens and actually harmful to many due to their already high sand content and related lack of soil microbial activity.
Natural plant decomposition results in a release of nutrients from dead plant material, but soils low in microbial activity tend to suffer from a build up of organic material (thatch) at the soil surface, which will become much more water retentive than desired. However, the answer to this does not lie with dilution of the organic layer with huge amounts of sand, but rather in reducing this layer through judicious and very regular aeration and core removal and the ongoing encouragement of soil microbial activity.
Where the soil is less than perfect for fine turf production, soil exchange programs consisting of hollow tining followed by top-dressing with a more desirable growing medium will still be required, but this is an entirely different subject.
Green Levels versus Surface Smoothness
There is a great difference between “Surface Smoothing” and “Surface Levelling”. Surface smoothness in this context relates to very minor discrepancies in the surface which can be rectified by a combination of surface aeration, rolling and light top-dressing.
Surface levels on the other hand cannot generally be greatly improved through even “Heavy” top dressing work. This term relates to much more severe changes in level which can be measured by laser survey and can be seen to have a visible affect on a wood’s traverse across the green.
“Heavy Topdressing” usually defined as dressings over 6 tonnes will not have a dramatic effect on surface levels and are more in keeping with the type of operation required by new greens for the first 2 to 3 seasons to achieve the final levels not ironed out during construction.
I say this because if you do the calculations, a 10 tonne dressing over an average green (1400 m2) will result in a maximum coverage of 4mm, which is only suitable for smoothing out the smallest of imperfections.
By far the biggest culprit in poor levels is excessive thatch which moves, swells, compacts and contracts continually. Trying to keep up with this with top-dressing is futile.
Going back to the main issue of greens drying out, the average bowling club in the UK is finding it difficult to find the money to irrigate the green sufficiently during dry weather. Again when we look at the numbers, the average automatic irrigation system throws out approximately 1mm of water for every 2 minutes of run time.
Now I visit a lot of bowling clubs and I know that many of them rely on “rule of thumb” measurements like 4 minutes per head etc when timing irrigation. Well, on average a green will lose 25mm of moisture to evapo-transpiration (a measure of the combined effects of soil evaporation and plant transpiration) and that’s from a healthy green in a normal dry week. This doesn’t take account of excessively high sand content, drying winds or existing dry patch problems etc.
To simply replace the moisture lost from one day’s evapo-transpiration you need to run your irrigation system for 8 minutes per head, that’s double and in some cases several times what many clubs are doing. Over a 7 day period this equates to 50 minutes of run time per head.
Turning back to Localised Dry Patch. This is a condition that causes large sections of the green surface to turn brown due to lack of moisture. No amount of irrigation will make these areas re-wet. They are literally hydrophobic or water repellent. Careful use of wetting agents and hand watering can make some improvement, but usually it takes a wet winter to bring about full re-wetting. The main trouble with LDP is its tendency to make the green bumpy. This happens when the baked dry thatch layer on top of the soil starts to shrink below the surface of the surrounding healthy turf. Irrigation makes the problem worse as the healthy areas grow more and the dry areas recede further.
To crown it all, continued heavy use of the irrigation system in the desperate effort to bring these areas back to life, starts to encourage thatch fungus, which eventually sinks and causes an even more uneven surface.
The Performance Bowling Greens program isn’t completely anti-top-dressing, but I have found that very few greens, at least in the UK, can actually cope with the damage that would be inflicted by applying more sand. The program recognises that some greens will still require top-dressing and gives advice on this.
However, the most important aspect of the programs I recommend for most greens is that they focus on returning bowling greens to healthy, living eco-systems that are not only disease and pest resistant, but also in a condition that helps the club to provide their members with a consistently high performance playing surface that can be set up predictably over the entire playing season.
The Performance Bowling Greens Program is set out in comprehensive detail in Performance Bowling Greens, a practical guide.
Autumn Bowling Green Maintenance always raises a lot of questions. Top dressing continues to be the most concerning topic for many readers. Should we top dress? Is it OK not to? And...if we do, what should we use? Master Greenkeeper John Quinn answers readers' most pressing queries about Autumn Bowling Green Maintenance.
Its time again for clubs to be thinking about the end of season maintenance program and many of these programs will follow “tradition” and will include the application of several tonnes of high sand content top-dressing.
However, one of the most prevalent problems on bowling greens in the UK is that of Localised Dry Patch LDP a condition that causes soil to become hydrophobic (water repellent) and which is undoubtedly related to excessive sand content in rootzone
The autumn renovation program is the only real chance clubs have to start to make inroads into the major problems with their greens and the only time when it is possible to make large corrections to thatch and compaction; and you’ve guessed it, thatch is another major problem associated with LDP.
Localised Dry Patch creates large dry areas on greens where grass dies back and the surface is disrupted. All attempts to re-wet these areas by watering the green are doomed to failure due to the water repellent nature of the underlying soil.
The application of yet more sandy top-dressing is not going to make this better; indeed it will in most cases make the problem worse next year.
It would be more beneficial to start the process of recovery by following a program that includes thatch reduction, wetting agent application and overseeding. All autumn programs should include the application of a granular fertiliser to correct any underlying deficiencies, usually a low N and high K product.
Where moss is a problem; and with LDP it usually is, you should use a proprietary moss-killer or lawn sand between 2 and 4 weeks before thatch removal work.
A very general title for today’s article, but it reflects the current industry desire for a fix all solution to achieving a good bowling green.
Most clubs are unhappy to some extent with the performance of their bowling greens.
This leads to an open ended search for solutions where the searcher i.e. the bowling club or bowling club management official simply looks for information from whatever source to help with the perennial problem of the bowling green.
If this is you, if you simply don’t know where to start in your quest for the truth about achieving a consistently good bowling green here is my suggested reading in order of importance. You can click on these links for more in depth information:
Over the years I have come up against a lot of friction when I have proposed that a club stops top-dressing its green with sand laden top-dressing compost.
The reasons for stopping this practice are well documented on this site (recap here) so I won’t go over old ground here today.
My guess is that a lot of greens, especially in the South East of the UK will be seeing some of the performance issues related to this “tradition” coming home to roost this year. The major disruptive force in bowling green maintenance is Localised Dry Patch (LDP) and this is a perfect year for it to show up at its worst. Again, LDP is extensively discussed on the site (recap here).
Another tradition which I suppose first came about for reasons of economy Read more
The autumn is traditionally a busy time for bowling green contractors, greenkeepers and club officials as they decide, plan and carry out the autumn renovation works on the green before putting it to bed for the winter.
Now have a look back over that last paragraph; if you didn’t wince at least twice, then it’s possible that you are about to embark on a program of work that will actually harm your green.
It probably won’t be dramatic like the sudden death of your green for ever, but it will probably have a negative impact on the future of your green’s ability to be presented for play consistently well, and maybe even on your club’s chance of survival in these harsh economic conditions.
The points I am referring to are Read more
In less than a week my new book, Performance Bowling Greens will be launched on this site; 15th of February to be precise. In the lead up to the launch we have been looking into some of the obstacles that stand in the way of the average bowling club achieving the performance they desire from their green. Today I want to look at one of those obstacles more closely and that is the obstacle that Tradition puts in our way. The trouble is that many of these “traditions” are really not that old. One of the most damaging of these is the “tradition” of top-dressing our greens with high sand content dressings every year.
Now I should warn you at the outset that this is a long one and you might want to grab a coffee before we get started. The reason for the length of this article is that I don’t just want to discuss the process of top-dressing; I also want to show you how damaging it can be to your green and how damaging it can be to your wallet. To do that I am going to re-present to you 3 of the most clicked on articles we’ve ever published on this site (which shows, I think, that many clubs already understand the problem). So here we go:
At most bowling clubs the end of September is when thoughts will start to turn to the autumn renovation program or the “closing of the green” as many clubs call it. Bowling clubs throughout the UK will take delivery of between 3 and 10 tonnes of very expensive top-dressing compost, which will be applied to the green after hollow tining or some other aeration operation, in the belief that Read more
I still get incredulous emails and phone calls about my advice to generally stop top-dressing.
In the last 10 years I have only visited one club where I recommended sand top dressing as part of the renovation program and this was due to total neglect and lack of any real maintenance other than cutting and fertilising for a very long time before that. The club in question unfortunately didn’t get as far as implementing the renovation plan and has now been replaced by 4 new family homes!
The top dressing “tradition” has become so ingrained in bowling greenkeeping that it is very difficult for a lot of people to get their heads around it when someone says “don’t do it”.
Here are my top ten reasons not to top dress:
- It makes healthy soil inert and unable to provide plant nutrition
- It encourages thatch build up due to low soil microbe populations
- This saps green speed
- and encourages fungal disease
- It results in Localised Dry Patch (LDP)
- This results in bumpy and uneven surfaces
- It is expensive and unnecessary
- It causes layering and root-break in the turf
- It contributes enormously to the Circle of Decline
- If you keep doing what you’ve always done, don’t be surprised when you keep getting what you’ve always got!
More info on why you shouldn’t be top-dressing here.
Spring bowling green renovation should be focussed on 3 main components:
1. the completion of the winter, deep aeration program
2. rejuvenation and aeration of the green surface
3. nutritional corrections
On greens in the non-drought affected areas of the UK, it should still be OK to carry out slit tining.
This is the last time we will get a chance to do this until autumn.
Two final operations with this machine will make all the difference to the greens ability to resist compaction in the early part of the season.
In drier areas, mini solid tining might be preferable and this can be done in addition to the slit tining in other areas.
If you have a thatchy green; identified by spongy turf, disease problems in winter and general poor health; you should scarify the green quite harshly in two directions to remove some of the fibre and mat that has built up over the winter months.
On healthier greens, where over-seeding was carried out last autumn you should avoid heavy scarification.
Lighter verti-cutting can commence once the sward is growing vigorously in May.
A question I get asked a lot is:
“ How much top-dressing should be applied in spring?”
The answer is a resounding “None”
Good luck with your spring bowling green renovation work.
Tomorrow we will have a look at turf nutrition requirements for pre-season