VINEYARD OBSERVATIONS - MAY 2026

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Nature gives and Nature takes… last year was very good (for most) but as for this year? - I think ‘merde!’ sums it up.

I started to write something for the Obs a few weeks ago that would have included a bit about frost protection but that went in the bin along with the other attempts – I’m finding it very hard to come up with anything vaguely positive!

The severity of the frost on the 24th (April) surprised many growers across the country and the continent while at the same time left a few wondering how they managed to escape with few or no scorched buds/shoots; two of the vineyards in my care escaped but since then all have been affected by more frosts (8thMay)– some completely wiped out, others with 40 to 60% loss. I have been on the land for 53 years and have never seen anything as bad.

The first frost was forecast but I and many others felt confident that the usual frost protection strategies would be sufficient- sadly not. The night started with a still air frost but the wind picked up later and this became a wind (advective) frost - Walsingham Estate measured -5.3 deg C and suffered even though there are two propane frost cannons and a large frost fan. Candles (or bougies), the Frolight system and various ‘frost hardeners’ e.g. Pro-act or Antifrost would have been used elsewhere but I doubt if they would have been sufficient – ADAS have trialled similar products and found them to of little use; mist irrigation would be effective and Linda Howard tells me that Frostec (?) worked – this year has been a severe test for the frost hardeners and it will be interesting to see which worked best.

One question I have heard recently – has climate change caused this (spate of frosts)? The answer is certainly ; the weather patterns have changed but to what extent human activity is responsible is open to discussion – I side with the science that says yes. In future will we bury our vines in the ground to escape frost damage as they do in Canada and China etc.? – I hope not!

I made enquiries about the foam frost protectant Frosco (there was an article about this in Fruit and Vine magazine last September and they had a stand at the Kent show last year)– George Klat from Frosco said -

“The application system is crucial. There are a couple of options. The main piece of equipment is a sufficiently powerful air compressor. We built a tractor mounted prototype foam system that uses a pto air compressor rated at 1100 lpm at 8 bar. Currently we have a 50% discount on Campagnola pto air compressors which we are willing to pass on to our customers in order to get them up and running. The ecoplus 1500 we use costs around £2500 for example.

The dedicated tractor mounted foam system will be available after we run more trials in the Southern Hemisphere. Currently it operates at 3 kph, one row at a time. With hydraulic rams it should be capable of applying foam to two rows at a time. This will retail around £10,000. We still need to find a manufacturer. I will look into FETF and see if we qualify. 

The simplest way is to use an air compressor on a three-point front hitch. We can integrate this into existing vineyard sprayers via the valve system we developed. Alternatively, a petrol powered compressor can be towed behind. In these situations we can supply the hoses, valves and nozzles. An integration kit. 

Foliar feeds can indeed be incorporated though each brand will require testing for compatibility. But seaweed foliar sprays for example work really well. The foam delivers a soluble feed to the leaves over many hours, making it a far more efficient method. The physical structure of the foam naturally lifts spores and dirt off surfaces via Marangoni flows. Rain washes it off. 

If applied correctly with proper equipment, the foam works reliably. It was tested to -8°C in Hungary, -5.5°C in Poland and -4°C here in the UK. The foam should be applied the same day as the frost event to avoid dehydration. The water fraction is crucial for buffering the foam's internal temperature at 0°C.

By the beginning of next year we will start taking orders for the foam sprayers for delivery in early March.” – I think the horse has already bolted… it looks promising but I think someone will come up with a similar system that can be applied through a vineyard sprayer – I’m working on it…

If your vines have ‘only’ been injured as opposed to damaged the secondary buds will eventually grow; if the secondary buds have been damaged as well then you could apply 90 kg/ha ammonium nitrate or 120 kg/ha calcium ammonium nitrate to the ground to stimulate any bud initiation in the crowns to grow new canes for next year - the knock on effect from these frosts will be felt for the next two years…

If the secondary buds survived then as soon as there is enough leaf – 50p size onwards - apply foliar feeds e.g. Polyverdol, FMC Complex, Omex Bio 20 etc – I rely on:

·Yara Croplift Pro 2.5 kg/100 litres water, or Yara Amplix Optitrac (formerly Biotrac) 1.5 l/100 litres as a ‘first aid kit’– this contains carbohydrates, sugar alcohols, amino acid/amino functional plant metabolites, organic acids, vitamins, anti-oxidants, Boron, Zinc, Nitrogen and Potassium. Follow label for further applications. For the boutique vineyards Miracle Gro and Maxicrop make a good combination.

· At inflorescence visible - magnesium nitrate at 2.5 kg/100 litres water – no higher concentration! Magnesium needed for chlorophyll, nitrogen for growth.

· At inflorescence expanded – calcium nitrate also at 2.5 kg/100 litres- calcium strengthens cell walls – again no higher concentration.

· At fruit set Yara Seniphos will supply calcium, nitrogen and phosphorus – P helps to reduce bunch stem necrosis.

· After fruit set Yara Safe N 300 is very good – it supplies slow, sustained N without the risk of ammonia scorch and mixes well with other PPP’s and foliar feeds; seaweed products are good for season long application with many different products to choose from e.g. Maxicrop, Omex Kelpak (kelp not Ascophyllum) etc etc – there is a whole raft of new biostimulants coming onto the market – whatever you decide upon read the labels!

If bud mites were a problem before the frost then use sulphur as well; downy mildew will also be a greater threat on the weakened vines so copper oxychloride and Option will provide good protection now that mancozeb is no longer approved. The canopy will not be as dense so botrytis shouldn’t be so rife, but powdery mildew will – protect accordingly.

Before the frost ruined all our hard work I did see more caterpillar damage but not from the usual suspect but for a change:     

All their caterpillars can be controlled with Lepinox or Xen Tari WG  – Tracer will control these as well but the EAMU states not to be used during flowering- can be used 3x p.a. so caterpillars and SWD can be controlled if you are fortunate enough to have any grapes.

All in all it’s a grim start to the year and I suspect it may make some wondering whether it’s worth continuing but remember the last thing Pandora pulled out of her box – hope!

Something to ponder – a little excerpt from H. Warner Allen’s preface of Viniana, written by C. W. Berry in 1934:

“The great vintages of 1864 and 1878 owed nothing to science (previous reference to Pasteur), and this generation at least will never see their like again. Phylloxera compelled growers to graft the French vines to the American stocks which are immune from the disease, and the grapes that are nourished by the sap drawn up through the coarser vine lose something of their quality and of their capacity for age even in a favourable year. Good wines are made from these grapes, but the magic touch is lacking”

There are still pockets of pre-phylloxera vines around the world producing tiny quantities of incredibly rare wine, e.g. the Henry Marionnet Provignage made from 0.36 ha of Romorantin (an ancient sibling of Chardonnay) planted in 1850. The question remains though – can you tell the difference between wines made from grafted and non-grafted vines?

The name Provignage on the bottle refers to the French term for layering (I didn’t know!) ; where a shoot or runner lies or is buried it will put out roots where it touches the ground and this technique is still used to replace lost vines in vineyards today – it isn’t illegal but the risk of phylloxera is still with us although it can be controlled with Movento

or Batavia. 

I know this edition of The Observations is somewhat disjointed, but it seems to be in keeping with the times….

As B.B. King sang “keep the pedal to the metal and don’t look back”

Graeme.