It’s that time of the year again when the question arises about the autumn bowling green maintenance program.
Topdressing
Of all the greenkeeping operations we do, top-dressing is certainly the most dramatic as it requires the delivery of bulk supplies of the top dressing medium of choice, usually something very sandy. And due to this relative drama; the big lorry delivering it over the hedge with a crane maybe and science and art of getting it spread evenly on the green by means of special machinery or sheer blood sweat and tears, it seems like it must be doing a lot of good.
It’s also at this time of year I start to get a lot of emails about top-dressing, many of which assume that I am dead set against it and for the most part, I am.
However, there is no one size fits all solution to the questions:
Should we be top-dressing?
Is it OK to hollow tine without top dressing afterwards?
Is it OK to not top-dress a Crown green?
Should we use 70/30, 60/40 or straight sand?
…and the many other questions that arise at this time.
The autumn renovation program you employ will very much depend on the current condition of your green and there’s no other way to know that other than going and having an educated look.
There’s a pressing need to get to grips with your turf and soil and to develop a deep understanding of your green eco-system that isn’t based on here-say or rumour.
I’ve written a series of articles to help with this assessment process starting here:
Autumn Bowling Green Maintenance Questions Answered
Top-dressing and hollow tining.
Q. If a crown green is hollow tined as part of autumn renovations, I always thought that it needed to be top dressed to refill the holes. Is this correct?
A. There’s no “one size fits all” answer to this and I’m certainly not anti-top-dressing. However, in the vast majority of UK greens there is already too much sand and it contributes to greens becoming inert, lifeless and susceptible to localised dry patch. 70/30 top-dressing is of course 70% sand.
It’s perfectly fine to hollow tine without topdressing. It depends what the purpose behind your decision to hollow tine is and the current condition of the green and soil.
Hollow tining is primarily a thatch removal tool, but even with jumbo tines (5/8″ at 2″ centres) you will only remove about 5% of the green surface area (5% of the thatch), so for dense, thick thatch, I usually recommend the use of the Graden GS04 or Sisis 600HD after the hollow tining. Using the Graden over the top of the cores can increase thatch removal to 20% when combined with hollow tining like this. This method also separates most of the thatch from the soil/rootzone. After brushing and cutting, the green is back to a fairly firm surface with no visible hollow tine holes and no need for top dressing as very little soil is removed by using this method.
Hollow tining is also used as a means of soil exchange when greens are very heavy (unimproved clay soil). By removing plugs of soil/thatch the holes can then be refilled with a sandier medium or straight sand if that is required.
What top-dressing should we buy?
Q. When ordering top-dressing for the green should we buy 70/30 or straight sand?
A. This will depend on current green conditions which can be assessed using the method detailed here. In addition to making an assessment of the need for top-dressing, the question of what type is a bit more complex than 70/30 or straight sand. In the quoted ratio the 70 refers only to the proportion of sand by weight in the top-dressing and the 30 refers to the material it has been ameliorated with such as peat or soil (the soil itself will contain more sand).
This tells us nothing about the actual material being purchased. The physical texture of the product is the most critical information to have. This is defined by the Particle Size Distribution (PSD). This measurement tells us what the actual contents are in terms of Sand, Silt and Clay.
Particle shape and hardness are also important and to a lesser extent the pH of the product.
Q. Following core sampling we have up to two inches of thatch in the wetter area of our green, the thatch is sour smelling and moss is more of a problem there as well. We were told that the soil registered as acidic. We want to help reduce the thatch thickness, correct the acidity and promote healthy grass growth.
A. The acidity will be part and parcel of the thatch and the associated compaction and anaerobic conditions. When you deal with the thatch and compaction, the soil pH will stabilise quite quickly.Regarding the correct program, you should probably leave out the top dressing and switch from a standard scarifier to something like the Graden GS04 after hollow tining at 2″ centres with jumbo (5/8″) tines. This will remove around 20% of the green surface (thatch), introduce a huge volume of air and get your microbes working on the thatch that remains. You might well have to repeat this next year.
Here’s my suggestion (you’ll have to decide if it suits your current conditions):
Hollow tining (5/8″ tines) at 2″ centres
Graden (or 600HD Sisis) over the top of the cores
Clean up debris, brush and clean up cut with mower (>6mm)
Twice monthly deep slit tining (Sisis Autoslit or similar) October to March.
Twice monthly cut (after slitting and when conditions allow) at 7 or 8mm
Some guidance on assessing the soil and turf conditions here
Questions Please.
If you have questions of your own about autumn maintenance or any other aspect of green maintenance, pease feel free to drop me a line using the contact form.
You can also drop a question in the comments area below.
Done for you, greenkeeping schedules
There is a growing list of clubs who get in touch with me to see if I can help them to set up a suitable greenkeeping schedule and I can certainly do this given a bit more information. To do this, I will usually ask clubs a few very specific questions about the condition of their green, ask for some photos in some cases, but most importantly, I will review the latest soil analysis for the green in question. Sometimes clubs already have a recent enough soil analysis and I’ll study this and then write a report with a full maintenance schedule aimed at making the improvements the club desires. If they don’t already have this information I can arrange a comprehensive soil analysis and then write my report based on this fresh information.
