April 22nd, 2025

Hi All,

Well we had a typical April Easter, a bit of sunshine, a bit of warmth and a bit of rain (well for us anyway here in The Midlands). The South West picked up more than its fair share of that rainfall as did Ireland but I'd argue though its effect on an Easter break might have been unwelcome, it was necessary.

Here we are sitting at 7.1mm for the month of April, following on from 10.2mm in March. Last year as a contrast, we had 171mm over the same period. This is the Ying and Yang of the jet stream, the driver of our weather. Last year it flowed strongly and sat unusually low and allowed a succession of Atlantic low pressures to dominate. This year, it has been sitting higher and crucially weaker in its flow which has allowed Omega blocking systems to develop, raising the jet stream up and pushing rain up and over us. This spring we can see we are dry in Ireland (until recently), dry across the U.K and dry across Scandinavia. We have also picked up more frosts to date this year than I think we have seen for a good while courtesy of a dominant easterly wind direction.

That drop of rain was nice for the garden, nice for unirrigated areas and nice for nature. I walked in Fineshades Forest near Toxic Town (Corby) yesterday in the drizzle and you could almost feel everything growing despite the air temperature struggling to make it into double figures. The smell was beautiful as well. Primrose, Bluebells, Cowslips and Stitchwort line the paths and I heard my first Cuckoo, now that's early ! Last week I fished Rutland into dusk and watched a lovely flock of House Martins feeding on the numerous midges hatching, indulging after their long migration from Africa. They positively chatted with joy. The Osprey was hunting (successfully) and as it got dark I watched an Otter do likewise. Such moments are to be treasured I think and good for the soul.

So a bit more rain would be welcome for some areas, particularly the middle of the country and across The North Sea I think in Denmark. Is it likely ?

14-day GFS projections courtesy of tropicaltidbits.com

General weather situation and outlook - w/c 22-04-25

If you look at the animated GIF above courtesy of tropicaltidbits.com you can see the dark green band that signifies the position and shape of the jet stream. It has been sitting low of late and that's what has allowed the rain to push in. Over the next 10 days or so we will see a bit of a rodeo ride going from a low position to a high and back again. So this will bringing weather more typical of an old fashioned April, some rain and some sunshine.

This week will start with rain pushing into the west of Ireland, crossing the country during Tuesday before moving across the Irish Sea into the west of England and Wales. This rain will then track south and east over The Midlands and central areas of England before crossing The Channel into France. Wednesday gives us a break day before we see the process repeat over Thursday as rain pushes into Ireland and then slowly crosses The Irish Sea into the west of the U.K later on Friday and onwards into the first part of the weekend. As we go into the weekend then we will see a dull and potentially wet (ish) Saturday but we will also pick up a warm air front which will see temperatures rise over the weekend into the high teens. I think we will lose the persistent frosts this week for all areas hopefully. For Denmark specifically, I can't see anything other than a dry week, slightly on the cool side with temperatures nudging into double figures and then picking up at the weekend as this milder air pushes over The North Sea. No sign on rain imminently here but maybe, just maybe that'll change in the 1st week of May, let's see.

Starting next week, there's some uncertainty in the forecast as we have a low pressure system popping into the weather picture. It wasn't there yesterday but it could bring an unsettled start to next week for the U.K & Ireland before high pressure and warmer weather looks to assert itself later in the week. So maybe some warmth and continuing dry weather for the 2nd half of last week.

Soil moisture surplus / deficit - Central England

Agronomic Notes

Last week I talked about the 'Haves and the Have nots' when it came to rainfall.

Above is a soil moisture surplus / deficit report from our Prodata Reports software for April 2025 (m.t.d) from our default location @ The Oxfordshire. This location tends to reflect a higher E.T, drier environment than most but it is useful I feel to show where some people are at, particularly across the middle of the country.

You can see we are at a soil moisture deficit of -54.5mm for the month when we compare rainfall vs. E.T, which is significant for the spring. This time last year we were in surplus after 72mm of rainfall for the month. The daily E.T figures are significant but as yet haven't breached the 4mm+ per day that I use as a benchmark to signify grass plant stress. So I would expect this scenario currently to be within the capabilities of most irrigation systems / localised hand watering to manage if soil moisture levels showed a dip requiring action. To put it in perspective, a dry summer's month could easily run up a 110 - 120mm deficit and back in 2018 I remember hitting -180mm soil moisture deficit. So yes in some areas we are dry, but I think it's manageable and of course great for business if you are a course on heavy soil.

Soil moisture surplus / deficit - Bristol area

By way of contrast I have added above the same rainfall vs. E.T dynamic for a golf course near Bristol / Bath, down in the south west of England. A lot more rain and a lot lower E.T because the environment is more humid so moisture is less able to evaporate into a more moisture-saturated atmosphere.

Management of these two scenarios this spring will obviously be completely different particularly when it comes to nutrition, plant growth regulators (as a management tool) and cutting.

Poa annua seedhead initiation and growth....

So I thought I would revisit the Growth-degree-day growth comparison chart I produced earlier in the year to show where we were / are sitting in 2025 vs. previous years.

Above is the updated chart with a horizontal line detailing the growth point (GDD @ 6°C = 180GDD from Jan 1st) when on this course the Poa annua var. reptans biotypes begins to commence seedhead development in earnest. It is worth pointing out that this is completely different from the var. annua biotypes which will produce a seedhead (particularly on higher height of cut turf) in any month of the year.

Applying this timeline reveals how consistent (despite the variability in our weather we experience) that date is. So this means at this particular location (Thame, Oxfordshire) we would be kicking into play our Poa annua management (grooming, brushing, light topdressing, keeping the cutting height at a point where differential growth isn't disrupting playability). Of course as I have already shown, the turf is super dry, so there's a very fine line that we have to tread which runs between management of the surface and not imparting more stress on the grass plant itself. It also shows we have caught up from our 'laggy' start to the year.

We have at the same time to be cognisant what is going on with that Poa plant. It is beginning to divert energy towards seedhead production and away from leaf / shoot growth, so its tillering potential becomes limited. That's part of the reason why a softly / softly approach is required in terms of surface work. Too aggressive and you'll thin the plant out and leave voids.

Great you might say, my Poa is hurting......but what is likely to fill those voids in the surface ? Poa annua var. annua for one, that clumpy, prolific seedhead producing biotype that stands out like a sore thumb and / or if it is dry, moss could encroach.

On the plus side this spring, the much higher DLI light levels have been great news for Bentgrass (and Ryegrass alike) so where you are managing a transition with a Poa / bent sward or Vicky versa (deliberate sp) that Bent should be looking and growing well.

Lastly, this dropped into my Inbox today and I would encourage all parties to respond because we need to give the regulators decent data to go on regarding pesticide usage. If we don't then we can't expect them to bring in applicable and well-informed legislation. If they can't measure after all, how do we expect them to manage ?

You can go direct to the survey link here

OK, that's me for another week, I won't be doing a blog next week as I hope to be chasing some early Norfolk Mullet across the sand flats 😉

All the best.

Mark Hunt