Another very popular subject on this site is over-seeding of greens in Autumn.
Over-seeding is commonly carried out as part of the autumn bowling green maintenance and renovation program and is very often a disappointment.
You would expect this work to quickly fill in the bare patches and spaces in the sward left by disease, localised dry patch and a host of other green problems, but this is very often not the case…why?
The answer to most disappointing results from over-seeding is “competition”. Competition from the mature, indigenous grasses whether fine or weed grasses like annual meadow grass usually reduces the success or survival rate from over-seeding to a very small percentage.
This quite often comes as a surprise to greenkeepers who have observed a very good “take” shortly after seeding (7-14 days). At this early stage it is not uncommon to see vigorous lines of dense new seedlings bursting forth from the green. This however, is usually a false reading.
Leading on from my previous article on over-seeding and the new over-seeding fact sheet , I have received a few enquiries about over-seeding of bowling greens this week.
A common question is about over-seeding rates, or how much seed to use.
There is of course no right or wrong answer to this as the rate can be adjusted to suit conditions, required effect etc.
So in some circumstances it might be necessary to over-seed very heavily to ensure a thick enough sward on a bare area for example.
At other times when using a particularly specialist seed mix the rate might be very light indeed.
As a general guide if you are using a traditional 80% fescue and 20% bent grass mix, then I would normally recommend a rate of 15-20g/m2.
Over a typical green of around 1400m2 the lower end of this scale would use about 1 full commercial bag of seed.
If a more specialist all bent grass over-seeding mix was being used then the application would go down to about 8g/m2 to reflect the major difference in seed size and weight.
It’s always best to try to divide the application into two passes with the machine as this helps to avoid missed areas and gives a more uniform finish. This is all the more important when using all bent mixtures as you can’t actually see the seed once it’s been applied due to its size.
5 tips for getting this operation right are:
Choose a high quality seed mix which utilises cultivars from near the top of the STRI turfgrass manual.
Calibrate machinery accurately as even a small error in adjustment can waste a lot of expensive seed.
Always apply seed into rather than onto the bowling green surface.
Heavy sowings can encourage Damping Off disease so take care.
Always apply seed in at least two passes in different directions.
Over-seeding of bowling greens seems like a straight-forward task; you put the seed on and the green’s bare areas recover.
However, one of our regular readers has raised an interesting question today about over-seeding and it is by no means isolated.
After over-seeding the green, the seed has taken well on the parts of the green that least needed it and nothing has happened on the barest areas of the green where the new grass is most needed!
This is unfortunately a very common problem and is usually related to our old friend Localised Dry Patch (LDP).
The barest areas of the green going into the autumn are usually the spots that have been affected by LDP and as such are bare due to lack of soil moisture.
This means that quite a lot of preparation is required before seeding and this might even include heavy watering to get the soil to hold enough moisture to get the seed off to a good start.
It might be necessary to do some light cultivation with a Sarrell roller or hand cultivator and, if the underlying soil is still dry and water repellent, a wetting agent would also help.
The main problem is that we are now a bit late for further seeding, although this largely depends on the weather and temperature. I have seeded successfully up to Christmas in the past, but success with this is obviously dependent on the remainder of the winter. Certainly if we were to get another one like last year, even early seedings will struggle to survive the winter.
If anybody is still having trouble getting grass cover on the green after overseeding please feel free to contribute ideas, tips or questions to the site.