Hi All,

After last week’s dry weather, another week of warm days, cold nights and no rain is on the cards I’m afraid, but looking longer-term, I think I can see a subtle change in the weather patterns, more of this later.

General Weather Situation

Watching Countryfile last night (the program was based in Leicestershire & Rutland), their weather forecaster described the present weather situation as a ‘Mega Block’, caused by a meandering jet stream, old news really for followers of this blog, but nice to see everyone is waking up to the fact that the jet stream is and has been controlling our weather.

As hinted above, more of the same for this week with high pressure again the dominant weather system for the U.K and Ireland with warm daytime temperatures in their high teens (and perhaps breaking 20°C in some places, Ireland I think had its warmest March day on the east coast yesterday) and cold nights.(Last night we got down to -1.1°C here).. As we approach the end of the week, the wind will swing round to the north and it’ll feel decidedly cooler during the day. By Friday, the wind will really be pushing down from the north, so feeling very cold. This northerly cold theme continues into the weekend and if anything gets worse as Saturday looks like being particularly windy and therefore cold, possibly finishing the day with an overnight frost into Sunday. By Sunday, that north wind will drop, so it won’t feel quite as cold, but if you compare temperatures week on week, it’ll be 10°C colder during the day !

Outlook

As hinted earlier, I do sense a change in the underlying weather pattern is on the way, but we’re talking 10-14 days away at the moment and so that change could easily become a no-show, so I’m cautious. If it does transpire, the blocking high pressure system will shift westwards, out into The Atlantic and that will allow a colder, northerly, weather pattern to dominate. A likely consequence of this is that will also bring wetter weather on the back of it, pushed down across the U.K and Ireland. I have to stress this is just an inkling at present and we’re really looking from Easter Sunday onwards, so I’ll have a clearer idea by next Monday’s blog. So next week looks like being dry again, at least for the early part of the week, warmer than the weekend, but not as warm as this week, with light winds.

Agronomic Notes

These conditions, i.e dry and cold represent the worst combination to grow grass in, point blank. The soil temperature is up at 12°C + by midday, but it’s down to 5°C during the night, so grass growth is stop and start at best, particularly on high-sand content greens.

Purpling across a Poa / Bent sward in early Spring

This stop, start nature will manifest itself in the usual purpling across a grass sward, a typical feature of early spring growth. Here the grass plant is photosynthesising during the warm daytime temperatures and bright sunlight and producing glucose, but as temperatures drop sharply in the late afternoon, it is unable to translocate these sugars out of the leaf, so they accumulate and bind to a pigment in the leaf called Anthocyanin. This pigment is responsible for expressing the blue, purple or red colour in the leaf and so the grass takes on a red / purple appearance. The phenomenon is not universal across a sward, nor across 18 greens. It tends to be exhibited by different clones of Bentgrass and Poa plants in patches / clumps across a green, primarily by the ones that grow better in lower temperatures. Shady greens tend to exhibit this phenomenon more than greens in the open because the change in temperature is greater on this type of green during the day and night. If you look closely at the affected leaf, you’ll see it is only a feature of the upper leaf surface, i.e the one facing the sun, turn the leaf over and it’ll be green.

Nutrition-wise, we’re still fixed on ‘little and often’ liquid / water-soluble feeds applied in low water volumes (maximum 400L) to a grass leaf sitting in warm air, as opposed to a grass root sitting in cold soil. (as would be the case with a granular fertiliser). Try and make it a weekly application frequency to maximise growth potential during this period.

Soil moisture is becoming an issue in the surface and areas with light grass cover are crusting up, so if possible lightly irrigate these areas either early in the morning or during the day when it is warm. I appreciate the latter may not be practically feasible because the warm weather is certainly bringing out the golfer. It’s likely that we’re staying dry at least for the next 7-10 days, so this situation will only get worse. That said, the lower temperatures on the horizon will cut E.T (Evapotranspiration) rates right down so moisture loss should be less.

As with last week, I’d be tank-mixing in a biostimulant either with my wetting agent or my foliar application to maximise growth potential and minimise plant stress.

If anything changes from a rainfall or more precisely lack of rainfall perspective, I’ll update this blog during the week.

regards

Mark Hunt