Firstly an apology if you had trouble accessing the blog on Wednesday last week as our server was down over Tuesday night and didn’t really want to get out of bed the next morning.
I mentioned a few weeks ago to keep an eye out for some migrants (not those sort) as they travel south towards Africa and I was chuffed to see both on my Buddleia last week, topping up on some liquid nectar before heading off for warmer climes. It fascinates me how something so fragile as a Butterfly can achieve such a migration and stay intact.
As we edge towards the end of September, there was a reminder that we have colder days in store as my car had a covering of ice at 6.30 a.m on Saturday morning. Still it made for a beautiful sunrise over Thornton reservoir even if bright sunshine, no cloud cover and blue sky is a rubbish combination for fly fishing 🙁
Out walking (again) I noticed another reminder that winter is on the way as some plants are shutting down their chlorophyll production and allowing Anthocyanin to become the dominant leaf pigment. This is the red, purple pigment that typifies our autumn colours.This Virginia Creeper has changed over the last two weeks from green to beautiful red and already you can see some of the tree species out and about beginning the transition as well.
So after last weeks rain are we indeed on for three weeks of Indian Summer as the tabloids say ? Hmmmm personally I don’t think so as by my reckoning we should just get through next weekend before the weather breaks.
General Weather Forecast
It’s going to be a pretty easy weather forecast this week as we do indeed have high pressure in charge. So for Monday we have in some places a misty, foggy start but the sun will soon burn that off to leave a lovely dry, sunny autumn day across all of the U.K and Ireland. The wind will be light and from the east so that may mean it could take a little longer in some eastern coastal locations to become sunny as it’ll push Haar off The North Sea. In the west of the U.K and over Ireland that wind direction should be more southerly because of the proximity of the high pressure. Overnight temperatures were down at close to freezing, but they should soon rise up to the high teens, similar to Sunday.
Overnight into Tuesday we have a very similar picture with a cool night, though maybe a little warmer than Sunday’s. So again a misty start but the soon will soon burn through to give another beautiful autumn day for all locations of the U.K and Ireland. For sure some areas will see the fog and mist stay around for longer but it’ll be dry and very autumnal for everyone.
By midweek we have a very similar pattern but there will be a difference in temperatures between north and south because the centre of the high pressure will be over Scotland from midweek onwards. I therefore expect temperatures to climb into the high teens / low twenties in some Scottish locations from late Wednesday onwards, whereas further south they may be a little lower, just mid-teens because of a slight shift in the light to moderate wind to north easterly. Dry again for Wednesday though, so we can’t complain much can we ?
For Thursday we have a very similar picture, warm over Scotland during the day, but slightly cooler across central and southern regions of the U.K as well as over Wales and Ireland where we’ll see mid-teen temperatures in the autumn sunshine. Perhaps more in the way of cloud cover for eastern locations on Thursday and where you keep the cloud and that stronger north east wind, it’ll feel chilly for sure.
Finishing off what has been an easy week to relate to we have a similar picture for Friday. Warm and sunny over Scotland with temperatures again heading to the high teens and low twenties, but cooler and duller for some southern and eastern locations with mid-teen temperatures at best in that prevailing north easterly wind. Perhaps more in the way of sun again across Ireland, Wales and the western coastline of the U.K, as the effects of the Haar are less intrusive.
Onto the all important weekend and is it going to be another fine autumnal one ? (and therefore rubbish for chucking a fly) Well it looks to be dry and settled for the whole weekend though I believe there is a change on the way. So similar to the end of the week with substantial cloud cover giving way to sunshine over the west, but perhaps again more in the way of cloud cover and therefore lower temperatures in the south and east. Slightly cooler for Scotland as well as we move through the weekend because change is on the way (possibly)
There’s a bit of disagreement in the weather models as to how next week is going to play out with projections changing daily but I’ll put my hat in the ring nonetheless. I think we’ll see a very quick transition at the beginning of next week from settled high pressure to a strong westerly airflow courtesy of a very deep Atlantic low pressure sitting north west of the U.K. So this will mean a change in the wind direction to south westerly / westerly and an increase in the wind as well. Westerly air streams invariably bring rain and that’s what you can expect I think. (though it could easily tip the other way you know) So a sunshine and showers type week with some significant rain around as well, possibly more for the west and north, but we should all see some. You’ll know who is right weather forecast-wise if the wind swings round to the south west in Ireland and the south in the U.K during the course of Sunday. If it does then unsettled weather is on the way I’m afraid.
Using the weather window….
A few weeks ago I used the same title to describe a calm, dry week with a forecast of rain and I’ll do the same again today. There’s plenty of tasks that you can achieve this week with a dry forecast followed by rain or a dry week when we don’t have a lot of active growth (because the night time temperature will keep the handbrake on growth) followed by moisture and milder nights when the unsettled weather arrives.
Renovating and overseeding
A great time to achieve this, though it was even better three weeks ago (more on that later) because we still decent soil temperature although it’s dropped off markedly over the weekend with the arrival of some cold nights and frost. Currently I’m measuring soil temperature at 11.4°C, but I expect that to climb over the latter part of next weekend / early part of next week as we pick up some milder nights. I’d still expect ryegrass seed to pop in 7-10 days with current temperatures so renovating tees, thin areas around greens and worn areas on sports pitches is still more than worthwhile.
After the summer, the wet August and wetter September this year than last (unless you’re in Scotland that is where it’s been a real dry September and long overdue) there’s significant amounts of weed around within the grass sward. Hitting it with a selective herbicide this week will give you a great knock back when moisture arrives next week and allow grass to fill in the vacated area before winter sets in. For that reason combining it with a liquid or water-soluble fertiliser makes a lot of sense.
Currently the disease pressure is quite low though you can see Microdochium in the dew on untreated areas but as soon as the sward dries out, it fades away. Expect this to change next week, not massively because it won’t be a warm, low pressure but with extended periods of leaf wetness, I would expect to see increased Microdochium activity. If you haven’t sprayed a preventative fungicide then now is your time because you’ll get reasonable uptake this week and spraying conditions are optimum, whereas next week, job’s buggered I think for spraying.
September and October always strike me as ‘Steady as she goes’ type conditions in terms of plant nutrition unless you need to push the sward for recovery (renovated areas, sportsfields, etc). The intention is to keep plant health up, with no peaks or troughs and ensure that you’re not taking soft, lush growth on fine turf into the autumn. On the flipside running it in weak with low leaf tissue nitrogen levels is also a likely calling card for disease with Microdochium, Anthracnose and Plant Parasitic Nematodes, all happy to take out a weak, under-nourished plant. You’ll know what the balance point is but there’s no prize for having a low N input, a weak plant and poor grass cover going into the winter.
I appreciate some of you will read this, scoff and think that it’s just the ramblings of a ‘Fertiliser Salesman’ (Copyright Jamie :)) , but face facts. Once we lose light levels and temperature and have no control over moisture, Poa annua will out-compete whatever desirable grass species you’re trying to keep or encourage, be that Fescue, Creeping or Colonial Bentgrass. I’d love it to be different, but it isn’t.
This picture was taken on the 8th January, 2013 during a mild, wet spell in the winter and you can clearly see which plant is growing and which plant isn’t. Perennial Poa is still in Christmas, happy mode and Creeping Bentgrass has battened down the hatches and is awaiting for longer days, more light and some higher temperatures.
Why earlier is better when it comes to renovation….
Always a contentious topic when it comes to sportsfields or greens maintenance and oft I’ve heard the comment “The surfaces were lovely and now you’ve gone and put holes in them and covered them in sand” or my mum’s favourite “The greens are like a beach….” (classic :)).
It’s so difficult to communicate why we need to aerate our surfaces before the winter, de-compact, introduce oxygen, remove organic matter, etc and I was thinking about this whilst fishing over the weekend (see Mark and Andy I need more time off to go fishing as that’s when I do my thinking….:)).
First off, you’re trying to tell a member of the public that although the surfaces look good now, if you don’t do the work they won’t stay that way. Now since most people attend the “If it ain’t broke, don’t fix it” school of life, you’re skating on thin ice before you start.
Then there’s the next hurdle to overcome…“Why do this aeration now, in July / August (delete where applicable), why not wait till we’ve got our fixtures done at the end of September / October / November ?” (delete where applicable)
Quantifying an argument using data is the best way to communicate in my humble opinion and so I thought I’d use Growth Potential to do this. Now I know some of you think recording GDD and Growth Potential is just playing with numbers, but the more I do it, the more I appreciate how it allows us to quantify growth and that’s what we need to do to make a good argument to the powers-that-be.
So here’s my thinking…we know that Growth Potential (G.P) is a measurement of the potential growth of a grass plant over a set period based on optimum air temperature and that it returns a maximum figure of 1.0, if the potential is optimum and a minimum figure of 0.0, if growth is non-existent (because it’s too cold).
So if we have 7 days of optimum growth, the total growth potential would be 7 x 1.0 = 7.0. I then looked at the last 3 months, split it into 7 day periods and totalled up the actual 7-day Growth Potential and expressed it as a %. So if we had a week where the actual G.P for that week was 3.5 and the total theoretical growth potential for the same period is 7.0, then we can calculate that the actual growth potential for that week was 3.5 / 7.0 = 50%. Hopefully you can follow my logic…Here’s how July, August and September (to date) look using that principle…
So what we can see from the graph is that during July we have nearly optimum growth conditions with week 2 and 3 best at 97 and 98%. Incidentally week 1 was down at 82% because it was very hot and that provided below-optimum conditions for growth.
Moving onto August we still had a pretty rosy picture with week 1 and 2 close to or above 90% and even the last week of August we’re still at 85% of maximum. This means that we’ll have excellent recovery from aeration.
Look what happens though when we get to September, the wheels start to come off a bit with a massive drop in the first week of September, down to 55%. So this is nearly half of what we had in August on a weekly basis. What we can assume then is that if it takes say 10 days to get recovery from hollow coring when we’re at 97%, I’d expect that to be 20 days when we’re at 50% or close to it. The reason why we had such a drop-off at the beginning of September was because we picked up some cold nights. By the time we get to the last week of September we’re looking at 41%, so 2.5 times as long to get recovery.
So that’s why the ideal is to aerate in August and as we get through September, the potential for good recovery and growth drops away significantly. I think it’s a great way to communicate a point to your hierarchy and will continue to plot this through October and November.
If you’re interested I will prepare a fact sheet using these stats and put it on the blog next week for downloading ? Comments please to the usual place…
Ok must dash, Tempus fugit !
All the best…