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Top Dressing Bowling Green

The Great Top-Dressing Debate

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.

Thatch

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.

Soil Exchange

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.

Irrigation

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.

Catch 22

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 Alternative

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.

18 comments

  1. Eric G Quiney says:

    I’m having difficulty in persuading the Bowling Club Committee in not using Top Dressing on the Green. they argue that it is necessary to cover the newly laid seed and infill the holes after hollow tining the Green. How do I counter their argument and do we just sow the new seeds on the surface then pass a Drag-mat over them ?

    • John Quinn says:

      Hi Eric

      Thanks for your message.

      The process I recommend for thatchy, inert greens is as follows:

      1. Hollow tine with 5/8″ tines at 2″ centres…leave the cores on the green.
      2. Immediately after hollow tining, use a heavy duty slotter (Graden/Sisis have suitable machines) in the same direction as the hollow tiner.
      3. Clear the resulting debris (snow shovel is good)
      4. Over seed the green using a seeder that inserts the seed into the surface such as a pro-seeder or verti-seeder.
      5. Brush the remaining rootzone/topsoil material into the grooves left by the slotter.
      6. Cut the green with an old mower at about 6-7mm

      Using this method you can remove around 20% of the surface and therefore a lot of thatch. You will also introduce a significant amount of air to the soil which will accelerate the natural breakdown of thatch afterwards.

      The slotter will close the hollow tine holes over and the brush will ensure that the grooves from the slotter are filled without adding any top-dressing.

      Some seed will remain on the surface, but the majority of it will be under the surface ready to germinate.

      If your green is really thatchy, over-seeding will be largely ineffective anyway. Sometimes it takes two to three seasons of this kind of work before the green is ready for seed.

      Let me know what you think.

      Regards

      John

      • Eric says:

        Hi John, sorry for late reply, computer problems. We do not have the machinery, or the means to purchase any of the ones you suggest, so I’ll just have to go along with committee decisions and verticut, seed and top dress. trying to borrow a tining machine from a local bowling club which may help. Thanks and regards Eric

  2. Paul says:

    Hi John,
    Would you recommend top dressing on localised areas of the green to raise the levels back and if so would you aerate before hand.

    • John Quinn says:

      Hi Paul
      Thanks for your query.
      It’s probably impossible to maintain a perfectly level green, due to the fact that it is a living eco-system and will naturally develop high and low spots continually.
      If the sinkage is due to areas previously affected by thick thatch and/or localised dry patch, adding more sandy material will perpetuate the problem.
      If, however, the green is in good health then it is OK to try to build up areas by this method, although I would try use a less sandy compost than that usually specified for top dressing; perhaps even mixing your own using sand and peat or soil as long as the finished product is sterile and free of weed seeds.
      If you are trying this it’s a good idea, as you suggest, to provide a “key” by aerating and allowing some of the material to mix with the soil below.
      John

  3. Eric says:

    Hi John, We;ve managed to borrow a Sisis aerator with pencil and hollow tines, so it’s a step in the right direction

  4. Top Dressing says:

    Yes i agree with this article that Top Dressing is not always the right option but it can certainly considerably improve the playing surface on greens with heavy soils or when the green is severely compacted.

  5. Mavis Bent says:

    Hi there,

    We are in the middle of changing our greens man, due to ill health.
    At the moment it is difficult to decide who is right and who is wrong.
    The old greens man says that the green needs solid tinning and then
    put on the top soil and seed.
    The new greens man want to deep scarify,( as he says it would do the same job) top dress, seed and later on in the year (Oct.) solid tine if need be.
    The winter work will start on the 17th Sept. so the seed will
    germinate.
    I would appreciate your comments on this issue.
    Thanking you in anticipation.

    • John Quinn says:

      Hi Mavis

      Thank you for using the site.

      The short answer is: I don’t know.

      In order to advise you on this, I will need to know more about the current condition of the green.

      Can you tell me a bit more about the green in terms of the general playing condition, any problems experienced this season, such as bad rinks, bare patches, flooding, slow green speed etc.

      Also if you know if the green is compacted or if there is excessive thatch.

      If you have photos this will also help.

      More information about appraising your green condition here

      You can send any information to me directly using the contact form here or by using the Help feature here.

      I look forward to helping you with your green maintenance decision.

      John

  6. John Harrison says:

    Hi Our bowling green has had no maintenance work on it at all except cutting no green keeper etc so we have a plan to start a reconditioning of the green with very limited financial support.
    hollow tine green and clean debris away
    apply covering of top dressing
    use drag net to spread top dressing over green
    seed , fertilise and pray.
    is this about right

    • John Quinn says:

      Hi John

      Given what the article above is about, I wouldn’t jump straight in and invent a program based on the conventional greenkeeping you probably see at other clubs, which this sounds like.

      If your green really has had no maintenance other than cutting then you probably have a great opportunity to start at a point many clubs would die for.

      I don’t recommend Prayer as a rule.

      The way to start is to assess what you have and to make up a plan from there based on the needs of the green.

      Make sure you know why you are doing things and don’t just follow convention. You’ll speed up the improvement process and avoid a lot of problems that way.

      This article will help you to assess the current situation:

      Fix your green step 1

      Please feel free to contact me for further support with this.

      Cheers

      John

  7. Malcolm Baker says:

    Hi John
    We are using purity do you recommend it.
    We also have an infestation of worms,Have you any advice as to dealing with the problem.

    • John Quinn says:

      Hi Malcolm

      I’d never heard of Purity until now. I’ve looked it up now of course. Why are you using it? Is it to reduce worm activity?

      Worms are generally beneficial and of the 50 or so earthworm species we have, only 3 of them create surface casts.

      Tight knit, perennial (bent/fescue) turf with minimal thatch is the best answer to this and I find it’s better to think in these terms rather than to treat individual symptoms that appear. My Performance Greens Program is aimed at producing, healthy, perennial grass dominated greens that are living eco-systems.

      Conventional maintenance over the last 4 or 5 decades has left a lot of greens inert, overly sandy and riddled with problems like this.

      The casting worms are surface feeders, so keeping the surface clean of debris will help in autumn/winter when they tend to be at their peak of casting activity. A light application of Sulphur might also help reduce activity in the meantime. Early results from tests with Salicylic Acid formulations have also been promising, but the overall picture of green health is still the real answer to controlling such problems.

      How is the overall condition of your green? Have a look at this newsletter for some ideas on assessing overall condition.

      If you need help, please come back to me.

      Regards

      John

  8. Kevin says:

    Hi our green has got what we call tram lines and if your bowl goes in the line it will follow the line.plus when walking on the green you can feel how spunchy under your feet it is and you can see the marks and the green is full of bumps. and the bowl hits the bumps and u never get the same line twice.would top soil and screeding the top soil help they just brush the top soil in after coring it?

    • John Quinn says:

      Hi Kevin

      It’s almost certainly excess thatch build up at the surface that’s causing this.

      Regardless of the technique used for spreading or working it in, top-dressing will simply bury this problem and not fix it.

      Have a look at this recent newsletter to see how to assess the problems properly and email me if you’d like me to help.

      Thanks for using the site

      John

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