Well the fickle continental rain didn’t quite arrive on the days I forecast, but arrive it did! We collected 28mm overnight Wednesday / Thursday, another 24mm overnight Friday into Saturday and today (Tuesday) the rain gauge is up to 12mm so far today and the radar is showing rain for the rest of the morning. Receiving 3 inches of rain in such a short space of time brings with it some consequences for those of us maintaining turf but more of that later. Our situation with the fractured jet stream continues, currently the strongest part of it is sitting down near Africa, and rather bizarely once we get towards the end of the week, our weather will not be subject to a high or low dominant pressure system, we’re just going to be sitting in a vacuum for a few days. As I commented back in April: having a jet stream that sits south increases the chance of cooler, wetter conditions and that’s certainly the case if you look at the Unisys loop above. The trough is stretching right across from America to Russia, with nothing moving from left to right due to the non-functional jet stream.
General Weather Situation
So let’s kick things off and see how the week and the outlook pan out. Tuesday kicks off fine and dry for Ireland, but for the west coast of the U.K. and the east, there’s a band of rain present. For The Midlands and east coast of England, rain is set to move off the continent to bring a soggy day for sure and, looking out of my office window, I can see that’s the case. Temperatures are nothing to shout about, low to mid-teens for most but, north of this rain band, it shouldn’t be too bad a day, though cloud cover will peg temperatures back in the easterly / north-easterly winds.
Overnight into Wednesday, that continental rain slowly sinks south-west affecting the east and south-east areas of England and Wales. Further north of it looks good and again Ireland looks to have a fair day with a sunny start. As we approach Wednesday morning rush hour, there’s a potential for heavy rain to move in off the continent to affect The Midlands and north of England, with another band threatening the Home Counties. Currently it’s projected to affect an area from London up to York, with the heaviest rain over The Midlands. By the afternoon, that rain is moving westwards into Wales and as it does it pushes cloud cover across Ireland. By Wednesday evening the rain moves into Leinster and Munster, but dissipates as it does so… Temperatures remain low for the end of May under that cloud and rain, but north of this into Scotland, the outlook is much drier and temperatures should push up to mid-high teens in places.
As we move into Thursday, that rain is still pulling in off the continent, so again for that belt stretching from London up to York, Thursday looks potentially wet I’m afraid and that rain is extending all the way across the Irish Sea so a showery day for Ireland with rain moving across country from east to the west (now you don’t often read that about Ireland and its rainfall :)). As we progress through Thursday, the rain begins to lighten and clear and as it does so, there’ll be much more sun over Scotland and the north of England. It won’t be ’til late in the day that it clears the west and Ireland though. Temperatures will be a little higher in this lighter rain and the winds again will be light and from the east.
Closing off the week, we will see the last of that light rain pushing off the south-west of England and, behind it as we lose the cloud cover; the sun comes out pushing temperatures nicely into the high teens and potentially higher, so we finish the week with a nice day and hopefully a dry cut! Winds will remain easterly / north-easterly and light.
So how are we looking for the weekend (Bank Holiday for Ireland I think)? Well not bad initially anyway, a lot drier for most of the U.K. and Ireland, with just a chance of some light rain affecting east Munster and Leinster on Saturday. There should be a good dollop of sun around for most areas and temperatures will be pleasant, high teens I think. Overnight into Sunday, there’s a chance of some light rain affecting central Scotland, but nothing significant. Sunday doesn’t look as good for Ireland though as a band of rain is set to push into west Munster and Connacht and push slowly eastwards, so the best of the weather here will be to the south and east of the country. There looks to be more cloud cover around on Sunday and maybe it’ll be heavy enough to kick off some showers over northern England later in the afternoon, but it should be dryish for most of us.
On a personal note, my advice is to get any outside jobs done over the weekend, get them beds and borders under control and lawns cut because you’re not going to get much chance the week after…
The low pressure system that is set to make the Irish Bank Holiday a bit of a drab one is set to drift south overnight on Sunday and introduce an unsettled theme for the start of June. This means rain will be an ever-present feature of next week’s weather I’m afraid, with potentially a very wet mid-week to end of week period as rain is pushed up from the south-west. There’s just a chance that following this low pressure system, a nice bit of warmth could come into play for w/c the 9th June, but don’t hold your breath….
As we round out May, the combination of high temperatures a week ago followed by heavy rain for a lot of areas has really ramped up the disease pressure with a wet leaf and high humidity aiding fungal growth. One disease that I’ve already seen a major increase in over the last few days is Red Thread. It just loves prolonged, wet conditions, with mild temperatures and the associated high humidity. Of course in the old days, Red Thread used to be associated with low fertility and the advice was to fertilise to increase growth and thereby directly remove the leaf and associated fungus. Nowadays we see it occurring on areas that are growing well and have been fed recently so that doesn’t seem to hold true. I think we see more Red Thread now primarily because of climatic conditions favouring its rapid establishment and because of the more frequent use of PGR’s. Think about it, if you slow down the rate of growth, particularly upright growth, you’ll remove less clippings and so less Red Thread fungi when you cut, so this allows the disease to become more established.
Now it’s a catch 22 situation because of course, when you have mild temperatures and frequent moisture, you are more likely to apply PGR’s to peg back growth. You’re damned if you do, and damned if you don’t :(! I also suspect that the modern-day Ryegrass cultivars are more susceptible to damage by Red Thread due to their finer leaf habit, but that’s just a hunch I have.
Of course Red Thread won’t be the only disease of note over this period with Fusarium sure to make an appearance and as I suggested last week, Fairy Ring and Superficial Fairy Rings. Now it’s difficult sometimes not to reach for the ChemSafe and put down a control, but key to avoiding this during this period is to make sure that the plant is healthy and with adequate, but not excessive nutrition. Secondly removing some of the contributing factors to disease, namely organic matter is a definite must-do if you want to see less Fusarium and Fairy Ring. Lastly and this is always a tricky call, keeping surfaces as dry as possible with light and frequent topdressing. Tricky because finding a weather and golfing window can be problematic (just look at last weeks and this weeks as an example) and also because the south part of the U.K. is currently suffering a shortage of good quality topdressing, with some of the established quarries closing down earlier this year. Quite how this will pan out longer-term is hard to say, but with competing industries for sand (construction, football pitch renovation, etc.) it doesn’t look great at the moment.
Pale and Washed-out Turf
It’s often easy to forget but when we get these huge hits of rainfall, nutrients are often lost quite quickly and so turf can go off colour. Simlarly areas that have been fertilised recently, particularly with foliar applications can look pale, even though it’s growing quite well. I think PGR’s can play a role in this because they definitely knock the colour out if they’re applied during cool and wet conditions. It’s not a criticism of PGR’s per say, more an observation and usually the effect is temporary.
It’ll therefore come as no surprise to many that areas of turf will look a bit pale and pasty this week, particularly areas of outfield turf with high Poa content (which is still in the throws of seeding). With the rainfall forecast for areas this week and next week looking like another wet one, granular fertilisers are one way to pep up outfield surfaces at present, if they’re looking a bit washed out. Ideally an analysis with some iron in will work well (colour without growth), but although the temptation may be to apply a good hit of N, remember you’re going to need to cut the area as well! Alternatively if you’re lucky enough to find a spray window, then a small nutrient input with low temperature N forms and iron and magnesium to improve colour, should tide things over till the weather improves.
One last point that’s sometimes forgotten is when we have prolonged rainfall and hence wetter surfaces, we’re often cutting slightly lower because the mower tends to sink down into the soft upper organic matter layer and so the bottom blade is cutting lower. I’ve seen a machine that’s bench set at 3.5mm, cutting a mm lower in such a scenario and because we’ve taken more leaf off, we lose some colour.
A tad tricky out there at the moment, so fingers-crossed for a weather break sometime soon…
All the best