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Doing Nothing vs Trojan Horses

With the end of the bowling season in clear sight, many clubs will have acquired a familiar temporary feature over by the roadside hedge somewhere. If you look closely there will probably be a pallet or five of bagged top-dressing, ready to go on the green as part of the autumn renovation program.

The bags might be plain or they might be covered in text and graphics proclaiming all of the benefits for your turf that are held within.

They are essentially Trojan Horses, in that they appear to be bearing good news and gifts, but they are actually full of sand (up to 90%) and represent the continued insistence of many clubs and consultants to pursue a program of desertification of bowling greens in the UK.

When your green was first constructed, it probably had an 8-10” (200-250mm) deep layer of topsoil (rootzone). An average bulk density for topsoil would be around 1.6 tonnes/m3. If we say that the average green is 36m X 36m we get an area of 1296m2. The volume of soil required to fill this is calculated thus:

 1296 X 0.25 = 324m3

Using our bulk density average of 1.6 we can calculate weight of soil required as follows:

324 X 1.6 = 518 Tonnes. So our average green was built using approximately 518 tonnes of topsoil.

Most hollow tining operations can penetrate the soil to 4 inches (100mm) and this is usually used in conjunction with top-dressing. This then means that top-dressing operations have been concentrated on about 40% of the actual soil used to build the green (the top 4 inches). 40% of 518 tonnes is 207 tonnes.

30 years of top-dressing with 5 tonnes of material each time is equal to applying 150 tonnes of highly sandy material and this disregards the soil being removed by the hollow tiner! This also assumes that your club only jumped on the train to la la land in the 1980’s; many have been at it for at least a decade before that. I also know of some greens where they are routinely throwing 10 tonnes of straight sand on every year, so these figures are only averages and are probably leaning towards the less crazy end of the spectrum.

Is it any wonder then that greens suffer from localised dry patch, excessive thatch build up, powder dry inert soil, compaction, disease, low microbe populations etc, when almost all of the top 4 inches of the green has been replaced by sand?

If this is the plan for your club this autumn it would be better for your green, if you just do nothing. Yes, even neglecting the green and failing to undertake any autumn renovation would be much less harmful to the long term health and performance of the green than following this program.

Slime on Bowls Green

Another enquiry that suffered from our email address problem on the web form was this one:

What causes small patches of black “slime” on our green and what are the short and long term fixes? The patches are slippery.

Now this is an easier one to fix than the myriad of problems being experienced by the bees!

Slime on the green surface is an indicator of acidic soil conditions. This is likely to be accompanied by dense thatch, compaction and a general lack of health and anaerobic conditions in the green and soil. The soil pH is likely to be very low.

The circle of decline fleshes this out comprehensively.

Tackling the root cause is of course the best way to proceed in the long term and just about anything you read on this site about green maintenance will point you in the right direction, with frequent aeration being the most beneficial practice to concentrate on.

In the short term you can get rid of the slime by adding a teacup full of farmers lime to a bucket of tepid water.  Stir this until it is fully dissolved and then make up to 20 litres with cold water.  Make sure that this is fully mixed before adding to a knapsack sprayer and spot treating the areas of slime.

Use the sprayer as you would for any other application i.e. by walking over the area and spraying as you pass; don’t stand still to spray individual areas as this will result in overdosing and possible damage to the grass.

Walk over the green in two directions, pulling the trigger each time you come to a patch of slime.

Final precautions: Don’t handle the lime without eye and skin protection and make sure that the sprayer is clear of all total weed-killer that it might have been used for previously. Don’t be tempted to use the lime in its powder form on the green.

The great top dressing hoax

Top dressing with high sand content composts has become a tradition in bowling green maintenance but it is far from beneficial.

  1. After 3 decades of routine top-dressing most greens are “inert” and can’t support a population of beneficial soil microbes.
  2. Soil microbes break down thatch and release nutrition to the turf.
  3. High sand and thick thatch usually result in Localised Dry Patch which is a long lasting, devastating condition that causes the soil to repel water.
  4. The surface smoothing and levelling actions of top-dressing are massively over-sold and of very little relevance to producing a smooth, fast green.
  5. Most bowling green irrigation systems are inadequate to start with, but are completely useless in the face of localised dry patch.

The process of top-dressing a bowling green has become so ingrained in our maintenance practices that it is hard to find a club that doesn’t do it, but over the decades it has devastated a huge number of greens in the UK.

Do your green and your wallet a favour and break the habit this year.

Noxious Chemicals and Performance Bowls Greens

The English language has a habit of dressing things up to make them more palatable.

I wonder if meat would be so popular if we called beef, lamb and pork “dead cow”, “baby sheep” or “pig carcass”.

Sometimes of course if something is particularly hard to swallow we have to resort to French; I don’t think even the big 4 banks could sell many “death pledges” regardless of how desperate we were to get on the property ladder!

However, I have decided not to play along when it comes to producing Performance Bowling Greens and I now lump herbicides, insecticides and fungicides (pesticides) into my newly coined phrase “noxious chemicals”.

So it might come as some surprise that I am now going to advocate the continued use of these products.

The long term plan for any bowling green should be to wean it off of these products, but I still come across clubs who jump in with both feet too early and make their green even worse than it was.

Although done with the best of intentions, this can torpedo the whole program as members rebel against the new program.

If you have a thatchy, compacted, sour smelling green, you will need pesticides for the foreseeable future. However, the plan should be to move to spot treatment only whilst you undertake the real work of aeration and soil improvement.

Eventually, you can become smug like me and call them noxious chemicals, the use of which will never be entertained again.

Maybe we will eventually promote the opening day BBQ with a poster covered in dead baby animals!

Much more info on weaning your green off pesticides here.

The Circle of Decline—why many bowls greens never improve.

The diagram below shows the process that many poorly maintained bowling greens experience over a period of years if 3 basic maintenance issues are not addressed as a priority.

The top 3 issues on all fine turf are:

1. Thatch Control

2. Compaction Control

3. Turf Nutrition

the Circle of Decline, the reason many greens never improve

In addition to the top 3 there are of course other important issues such as irrigation management, topdressing etc, but if these 3 big issues are under-managed then the green will spiral into what I have called the Circle of Decline.

Simply put this is the course of events that go on largely un-noticed by many bowling clubs until it is too late to effect a quick recovery.

A lack of attention to thatch build up (see other posts under the thatch category) results in a thick mat of un-decomposed  dead grass shoots, roots and leaves. This mat gradually effects the turf’s ability to put down roots and take up water and nutrients. In advanced cases a root break will occur and Localised Dry Patch is a very common symptom of excessive thatch also (see other posts under the LDP category)

Disease

In winter, thatch can hold water like a sponge and encourage fungal diseases such as fusarium patch to take hold. This sometimes results in over use of chemical fungicides which kill off the disease and many beneficial fungi into the bargain.

Symbiosis

Grass relies on beneficial microbes, such as fungi to make best use of the available nutrition and so begins to have difficulty obtaining the necessary nutrition from the soil.

This often results in over fertilisation, as much of what is applied is not made available to the plants due to the anaerobic conditions which now prevail.

By now conditions are highly favourable to the weed annual meadow grass which is a very shallow rooting species. The finer fescue and bent grasses are compromised and in an effort to keep the meadow grass alive excessive irrigation is required.

This contributes even further to the excessive thatch layer as meadow grass is a prolific producer of thatch and we are back to the beginning of the cycle.

Action must be taken to break into the circle of decline, take action before its too late for your green.