Hi All,Mayfly

Well, not a bad Bank Holiday weather-wise, but it finished with a dose of rain for many. With this weeks rainfall and especially with yesterday being warm in many places (here in The Midlands we shaded 20°C), it isn’t going to be great to get areas back ‘in cut’.

I guess it comes as no surprise to you that I was out fishing for some of it 🙂 and had one of these settle in boat; it’s a Mayfly, aptly named of course, and quite rare nowadays on still waters. Sadly it generally only lives for one day in its adult form, but lovely to see if you like that kind of thing…

So how are we looking weather-wise? Well, cool and unsettled is the theme that we’ll take into mid-May: with that jet stream remaining low and allowing cool air to dominate the weather picture, I can’t see heat anytime soon :(. The good news however, from a turf growth perspective is that the unsettled picture means we lose the colder nights for the time-being, so that will allow good, consistent greens growth. More on that later.

General Weather Situation

For Tuesday we have a dry start for many after some heavy overnight rain. We had 6mm here, but I know The West received more than double that! That rain band will lighten, but still linger a little over the north-eastern coast of the U.K. clearing slowly. Elsewhere the sun will break through and it’ll be a pleasant day for many with temperatures in the mid-teens, possibly higher. For Ireland no sooner has the day started than a new rain band is pushing into the west coast and heading inland though it’s only projected to reach approximately half-way across the country, so draw a line up from say Mallow and left of it is wet, right of it is dry(ish). Scotland looks to be dry most of the day apart from some rain affecting the north-west later in the day. Winds will be moderate westerly / south-westerly.

Moving onto Wednesday that rain band pushes north-east and that kind of sets a trend for the main rainfall pattern this week. Affecting Ireland, the south-west / north-west of England and Scotland, as the bulk of the rain moves diagonally (/) across the U.K and Ireland. There’ll also be some rain lingering along the south-eastern coast of England / west coast of Ireland, early doors. As we move through the day there’s a risk of catching a shower in most places, but by late morning more rain is mowing across Ireland and into the west coast of the U.K affecting areas inland by early afternoon. This rain band is not expected to push much further east than Nottingham though, finishing off the day by pushing north-east again into northern England and Scotland. Elsewhere it’ll finish dry, with temperatures down on Tuesday by a couple of degrees due to more cloud cover.

Overnight into Thursday, we have another band of rain due to affect the south-west of U.K and Ireland (you get the picture by now, it’s a pretty unsettled week for many :(). This rain moves diagonally across both countries (\) to affect most areas through the day. Always difficult to say where will get the heaviest rainfall so use the radar on your Weathercheck for this purpose. The rain may not reach Scotland until the evening. Elsewhere the rain band will leave behind a raft of showers so Thursday looks unsettled with temperatures in the low to mid-teens, though as commented earlier, night temperatures will stay up nicely (unlike the end of last week). Winds will remain westerly / south-westerly.

We end the week much as we have spent most of it with a pretty unsettled day for many, especially in the west, north-west and north of the U.K. and Ireland. So we start the day with potentially heavy rain over the north-west of Ireland, England and Scotland and possibly North Wales. Through the morning this rain tracks south and eastwards to affect the north of England and potentially getting down as far as The Midlands, but we’ll see. The same happens across Ireland with that rainfall starting off in Donegal and then tracking east and south across country, again there’s a question mark as to how far south it’ll get. Through the afternoon that rainfall lightens and dissipates though still likely to affect the north-west coast of England and Scotland. Further south you may not even see the rain, so with clear skies you may pick up a couple more degrees of temperature, elsewhere it’ll be low to mid-teens with a brisk westerly wind.

At this stage it doesn’t look a very good forecast for the weekend, especially for Saturday with a band of heavy rain crossing the U.K. and Ireland and potentially taking most of the day to clear. It’ll also feel a bit cooler as cool moist air swings down from a low pressure system courtesy of that low-lying jet stream. Sunday looks marginally better, still very unsettled with bands of heavy showers and temperatures low teens in a cool, westerly / north-westerly wind.

Weather Outlook

Well not great really with the continuing low set jet stream, so next week looks like starting off possibly dry for the Monday, but thereafter we have an intense low pressure pushing rain in for Tuesday and Wednesday. We may have a brief lull in the rain for Thursday, but thereafter another low, not quite as intense as earlier in the week pushes in so; milder, but potentially wet for the north and west later in the week.

Agronomic Notes

There’s lots to talk about here after the Bank Holiday ;

GDD Information

Thanks to everyone for sending in their first 4 month totals, it makes interesting reading, have a look at some sample of locations and the April / y.t.d. End April 2014 readings ;


One thing that immediately strikes you is the highest GDD total is for North London (Muswell Hill actually, cheers Matt!) so I checked the figures to see why they’re so high and it’s interesting because it looks like locations in cities (or close to them) hold onto the day temperature longer, no doubt due to warmth being radiated off all those buildings, roadways, etc

Look at the average daytime and night time figures for April for 3 locations and you can see what I mean:


So that’s why North London is ‘Top of the Pops’ for total GDD: warmer nights through the Spring. It’s also interesting to compare locations and you can see the southern half of the U.K. is pretty similar by the time we get to the end of April.

GDD- How we stack up for the year

Wendy has been kindly slaving away with the number crunching to bring us up to date and this is how we look: (Download them here)


So you can see April wasn’t a bad growing month in terms of GDD, but the problem is / was the alternating temperatures through the month as explained last week and shown for the whole month below ;


So we had two main growth periods, one at the start of the month and one at the end, the middle was too variable to provide consistent growth, particularly on greens.

And Poa seedheads…

This has been reflected in Poa seedheads as well in that they first started to appear in early / mid-April on greens at about 170 GDD. These were mainly the annual Poa biotype seedheads and they slowly increased in number through the month, but visible seedheads were mainly isolated to this biotype. Curiously the timing was similar in different locations, even though the GDD was markedly different so this suggests that Poa seeding is not only influenced by temperature, day length may also play a part?

By the time we got into early May, the main Poa seedhead flush with both annual and perennial biotypes is well under way, so that’s about 230 – 250GDD over here and pretty much similar to other years (apart from last year when the season was much later) It’s noticeable that the GDD figures from Ireland are significantly lower for all locations except Kerry. It’s also clear that there’s a significant difference between the west and east coast in terms of growth potential, with the west further ahead in GDD terms. I would expect Poa to begin seeding earlier on the west coast than the east coast, anyone care to comment ?

Talking about growth…

I was looking at some surfaces last week that had been aerated and in the low lying areas the difference between the aerated and non-aerated areas was significant. It once again highlighted to me firstly the need for aeration and secondly how growth-limiting anaerobic soil situations can be, particularly when you have perennial Poa which grows in tight, densely-tillered patches.

See the images below:


Growth in aeration holes


Close up of growth in a tine hole – perennial Poa


Non-aerated area with suppressed growth due to lack of oxygen

By the way I fully appreciate that posting close up images with my digits somewhere in the mix firmly illustrates the fact that I bite my nails too much! But, if you were sitting in my seat most of the time, you would too… 🙂

We often have issues in the Spring with bumpy surfaces and uneven growth. It’s usually blamed on fertility, grass species, etc. and sometimes this is correct however, we must also take into account the fact that if an area has been aerated, you could see differential growth just because the plant is able to grow better due to more oxygen availability (which in turn increases respiration, nutrient uptake, etc.).

Now both areas (those that are responding and those that aren’t) may have received fertiliser, but it’s only the plants that have access to good soil oxygen levels that will respond. This is most marked on surfaces with high perennial Poa biotype populations (and therefore higher organic matter) and on those that might sit wet / anaerobic for some of the year (poorly drained rootzones, low spots on greens, etc.).

Warmer nights = more consistent greens growth

If you are seeing differential growth, you should try and aerate (spike or sarrell roll) to input oxygen over a wide surface area and also fertilise ‘little and often’ to maintain plant nutrient availability, not big spikes of nutrient, just a constant light input, with iron to maintain colour. One thing that will work in your favour coming up is the warmer night temperatures which will see growth rates hike up a bit as daily GDD’s will be around 5.5 to 6.0, even though the day temperatures are nothing to shout about. This should also grow out some of that pale turf aspect present on some areas at the moment.

Disease Activity

A quick round-up based on emails, phone calls, texts and visits indicates that we have some continued Fusarium pressure, particularly after the weekend with warmth and rainfall for many. I also expect to see more superficial Fairy Ring activity and the first signs of Ectoparasitic nematode damage manifesting itself.

PGR Applications

If you’re able (and it might be tricky this week with the rainfall), now is a good time to hit higher-height-of-cut areas with PGR’s because growth rates are likely to be strong with the milder nights. Don’t forget to put in some iron, especially on high Poa content turf because this will be the first to discolour with higher rates of PGR.

Ok, Ciao for now and all the best…

Mark Hunt