Category Archives: Guy’s newsletter

Guy’s news: “If you can’t measure it, you can’t manage it”

We taste everything that goes in your veg boxes; in fact at one time we tested the palates of all our staff and formed a panel from those with the most sensitivity. It was an admirably democratic exercise, but proved useless as it failed to accommodate the fact that taste is subjective, highly related to the individual and therefore defies objective measurement.

Forty years of business mantra maintains that if you can’t measure it, you can’t manage it. If you can’t manage it, the easiest thing to do is pretend that it doesn’t exist; an approach that has been misapplied to healthcare and education as well as the quality of vegetables. What measurables there are have improved over the years: shelf life, uniformity, yield, even the elements of flavour which can be quantified like sweetness and crunchiness/turgidity. However, these improvements have been won at the cost of harder to measure, more subtle flavours, and almost certainly nutritional quality. Flavour comes from the crop variety, soil type, growing conditions (most notably the availability of nitrogen and water) and freshness. The best flavour normally comes from vegetables and fruit that have grown slowly, often with a degree of hardship that falls just short of stress (which can result in bitter/off flavours). As such, most commercial farmers cannot risk aiming for flavour when cosmetic appearance is what their buyers will judge quality on.

Introducing…The Riverford Flavour Tour

To bring the focus of food back to flavour we are launching a hands-on, mouthwatering experience of organic vegetables farmed for flavour. Drop by for veg growing, cooking classes, veg games, tastings, demos, and much more! We’ll also be running our new Master Veg cookery classes and Pop-Up Feasts nationwide – see website for details.

WOMAD: 28th-30th July
Riverford on Home Farm: 4th-6th & 8th-9th Aug
Riverford on Sacrewell Farm: 18th-20th Aug
Abergavenny Food Festival: 16th-17th Sept

Guy’s news: Plants; not so dumb & passive

Much of horticulture is about managing the urge of plants to reproduce. Humans need and crave the more digestible, nutrient-dense food found in the reproductive parts of crops; that is the flowers, fruits, seeds, bulbs and tubers. As growers we devote ourselves to manipulating plants to maximise the yield and quality of those tender and tasty reproductive organs, which is a tricky balance to strike. If only we could sell you grass for your supper; alas the easy to grow, non-reproductive parts of plants are largely indigestible to humans.

Plants in their wild state have survived the challenges of pestilence, drought, flood, ice ages and now Homo sapiens by mastering a long-term strategy of balancing growth and dominance against risk. Getting bigger to increase their reproductive capacity must be balanced against the risk of not making it to maturity. At a cellular level the strategy all boils down to whether a cell in the apical meristem (growing point) differentiates into leaf or flower (above ground) and root or starch-saving tuber (below). If things are looking good a plant will
typically extend its vegetative life, assuming the chance for greater fecundity will come later; if things are getting tough (drought, lack of nutrients or light etc) it will switch to sexual mode early so at least some genes are preserved.

Such were my musings as I observed our early runner beans which have grown and grown but failed to produce a crop. The generally-held wisdom is to build a strong plant, then stress it with water deprivation to make it flower, then give it everything it needs so it feels confident and fills every pod. As our plants reach for the polytunnel roof and the soil is covered with aborted flowers and just a few crates of beans to show for it, it’s plain we haven’t grasped the subtleties.

There is a tendency to regard plants as dumb and passive, yet their interaction with the world goes far beyond the basic tropisms we learnt at school. They can sense, even “hear” pest attack and respond with defence chemicals, much as our own immune system works. They may not moo, baa or rush around, but the apparent passivity of plants hides subtleties and complex responses which have served them well. It remains to be seen how well they will survive us.

Guy Watson

Guy’s news: Hot, hot, hot

It hit 41˚C in the polytunnels yesterday; too hot for people and too hot for crops. Picking starts at 5am to get the cucumbers, salad onions and basil picked and tomatoes side-shooted before it becomes unbearable. Even the bees head for the exit when it reaches 30˚C, as would most humans. I’ve headed to some shade by the reservoir to write this; not a bad office for today.

On our French farm we hire a helicopter to spray lime on the tunnels which is remarkably effective at reducing temperatures and stopping the peppers getting sunburnt; it’s hard to believe, but in the quest for the perfect pepper we seem to have bred out tolerance to the sun. Such is my frustration with overbred veg and overpriced seed that we are experimenting with some older varieties from central Europe this year. Meanwhile our early tunnel-grown runner beans are aborting their fruit in confusion at the extreme heat, so we are yet to pick a bean. We have started picking the first padron peppers which will be available next week; they have so much more flavour than anything available in a supermarket or any tapas bar I’ve visited. Shallow or dry fried until 50% of the skin blisters and sprinkled with sea salt, they are the perfect appetiser.

Even outside the polytunnels the heat is causing stress in many crops, particularly our cool-loving brassicas. Plenty of water can help by affording the plant the chance to cool itself through evaporation from the leaves (as we do by sweating) but in this weather most farmers, us included, don’t have access to enough water pipes, pumps and sprinklers to get around needy crops and back to the start in time. Broccoli has been the worst affected; every head harvested this week ended up being fed to the cows. It was fine when picked but even with the best refrigeration nothing could undo the stress suffered in the field.

Sweetcorn on the other hand is lapping it up; it has a slightly different method of photosynthesis (the C4 pathway) which comes into its own as temperatures rise and water gets scarce. In France we have the biggest, greenest, most uniform crop I have seen in 30 years of growing, and expect to start picking some thumping cobs in early July ready for your BBQs.

Guy Watson

Guy’s news: Exodus; not a good time for slugs

For the last month, our irrigation reservoirs have been rimmed by a black mass of writhing tadpoles. I reckon there are over a million in the one I swim in, even after the carp have feasted. Last week they got their legs and this week they are off; the ground around the ponds is heaving as they go in search of their first terrestrial meal. Facing this hungry biblical plague, slugs have no chance. It will be two years before the toads return to breed, by which time they’ll have made a home on the waterless hill half a mile away.

“What we do about slugs” is always the visiting gardener’s top question on our organic farms. The answer, with the occasional exception of our polytunnels, is nothing; they aren’t a problem for our field crops. I know you will find the occasional slimy surprise in our lettuces and our sprouts are often scarred (which we hope and assume you can live with), but I cannot remember ever seeing any organic crops suffering significantly. Most conventional potato growers will routinely apply vast quantities of slug pellets and still have substantial damage. Likewise, slugs can be a huge problem in winter wheat and barley even after applying pellets, but almost never when the ground has been organic for three years or more. The reason is undoubtedly that our soils, free from pesticides and synthetic fertilisers, are teeming with life looking for a meal; toads, frogs and carabid beetles like to munch on slugs, nematodes will parasitize them, and there are almost certainly many other predators and pathogens. No-one makes money from their activity, so this unglamorous part of ecology hasn’t been studied much.

The principle of organic farming is to find balance; the population of every indigenous pest (except Homo sapiens) is regulated by predators and pathogens. It doesn’t always work; sometimes you have to encourage them a little (e.g. flowering plants to foster the lacewings and hoverflies that control aphids), but with slugs all you have to do is spare the soil those toxic chemicals, and soil ecology will do the rest. Annoyingly I know this approach does not work in a garden; I suspect there is just too much cover for the slugs to retreat to. If you can handle the poo and keep the foxes away, get a duck.

Guy Watson

Guy’s News: Baby orcas & the rarity of certainty

Last year a dead orca was washed ashore on the Isle of Tiree in Scotland. PCB (polychlorinated biphenyl) levels in its body were 20 times greater than what scientists consider manageable for cetaceans. The 20-year-old whale had not bred in its life; indeed observers have not seen any orcas born in British waters for 25 years and there is strong evidence of impaired reproduction in many sea mammals from heavily polluted European waters. PCBs were manufactured and marketed as coolants, lubricants and sealants by Monsanto and others for 30 years until their ban in the 1970s, when their toxicity could no longer be denied. The stability and persistence which contributed to their industrial value means they still pollute our oceans and waterways, and have accumulated in top predators globally. Clearly testing and regulation were inadequate. Manufacturers profited and moved on; the planet is still paying the price.

A recent report commissioned by the EU suggests the dangers posed by pesticides are underestimated and that the systems of safety assessment are flawed. The collective damage to our nervous systems and the consequent loss of IQ alone is valued at a staggering £125bn per year. I am a little sceptical as to how they arrived at that figure, but once again the NFU made my blood boil with their response: “It is important to point out that this report makes it quite clear that our understanding in these areas is limited, the evidence is not conclusive, and the significance of the findings for public safety is unclear.” So should we carry on using nerve toxins and endocrine disrupters until it is clear? Surely we don’t need 100% certainty to restrain the quest for profit at any cost?

Certainty is rare; perhaps there’s only a 50% chance that we are substantially underestimating the risks of pesticides, perhaps the chance of catastrophic anthropogenic climate change is only 80%. Yet for those with power to knowingly expose our planet and future generations to such risks in the name of profit is psychopathic. I am so tired of hearing farmers and businesses lobby for less regulation when there is such evidence that we need more. Sometimes it will be wrong and prove over-cautious, but that is a small price to pay for the times that it proves right.

Guy Watson

Guy’s news: A mixed start

Confusion – The pigeons nesting on top of my outside loo are already on their second brood; I feel something akin to a grandparent’s vicarious broody pride and have given them sole use for the summer. Outside the ash is finally in full leaf, almost a month after the oak. Folklore would have us believe “oak before ash, in for a splash; ash before oak, in for a soak” so we should be in for a dry summer, though personally I will not be counting my squab before they hatch.

A little woe – The mixture of precocity and tardiness is more likely down to confusion caused by wildly fluctuating spring temperatures. Under our crop covers it was bright and tropical by day bringing on rapid growth, but also stress when temperatures dropped and we struggled to keep up with the irrigation. Plants didn’t know whether to be a conservative ash or an adventurous oak. As so often happens when you stress a plant, some cash in and go to seed prematurely; we got a spinach crop but had to pick early, accept a reduced yield and spend a lot of time sorting. Pak choi did the oak thing, growing so fast under the covers that their roots couldn’t keep up. The result was that, just as we started to harvest, a proportion developed base rots (perhaps boron deficiency) and had to be discarded. Our final woe is weeds in the salads. We make ‘stale seedbeds’, typically three weeks ahead of sowing, in order to let weeds germinate and be killed (by a burner or shallow cultivation) ahead of our crop emerging. With scarce rain we had little pre-germination and have some weedy rocket, mustard, beet leaves and mizuna. Rather than abandon the crop our salads team spend their afternoons hand weeding to clear the area for harvest the next morning.

But still mostly good – So a near-perfect year so far has given us a few problems, but the dry weather has allowed us to plant on time and in good conditions, so though early crops have been the mixed bag they invariably are, the crops further ahead are looking excellent. Like my pigeon tenants, I remain optimistic.

Guy Watson

Guy’s news: Samphire canoes & cold milk

The rain came and went, leaving our soils recharged and our crops refreshed; just as we started to worry it would never stop, a week of dry weather allowed us to make silage and catch up on the sowing. I have to pinch myself lest we take this faultless weather for granted, but the near-perfect year continues.

After eight weeks of foraging for wild garlic in the woods, our nimble-fingered and flexible team of youths have had a short break before starting this week on marsh samphire. With wild garlic the challenge is avoiding the toxic weeds that share the same shady habitat, and then carrying the boxes out of the often steep woods. With samphire the challenge is the tide and the extreme fiddliness of the task. On a good day a picker may manage 10kg before being driven off the marsh by the incoming tide; they often end up paddling the crop to the margin in a canoe. The marshes are remote and staggeringly beautiful and occasionally I achieve a state of bliss when picking but, to my shame, my mind keeps trying to invent a machine to aid harvest. All my inventions so far have been discarded in favour of scissors and garden shears but I keep sketching inventions; the sign of a Zen-less Henry Ford-like mind.

One of the advantages of doing our own deliveries via your local veg team (rather than contracting out to drivers in the burgeoning “gig” delivery economy) is that we get our packaging back, so can ensure it is re-used or recycled. Our boxes are made from 98% recycled materials, are 100% recyclable and often used ten times or more but, counter-intuitively, still account for a larger carbon footprint than our road transport. The single biggest thing you can do to reduce the environmental impact of your fruit and veg (and help us keep prices down) is to fold the box (the bottom goes down, not up) and leave it out for your driver to collect. We are also starting to use silver bags cooled with ice packs to help look after chilled products better; we can use these many times if you put them out too. We cannot re-use other Riverford bags so, if your local authority recycles plastic bags please let them; if not put them (just ours please) in the empty box and we will recycle, and so close that loop.

Guy Watson

Guy’s news: I wish they wouldn’t call it ‘dirt’

A week of rain has restored soil water to ‘field capacity’, much to the relief of our crops and hard-pressed irrigation team. Field capacity is the maximum amount of water the soil can hold: what’s left clinging to the particles after gravity has drained away what it can, but before evaporation or root absorption remove any more. Imagine a wet sponge left to drain for a bit but not squeezed. The finer the particles and the larger the area, the more water can be held.

As a very general rule, well-established plants start to suffer when about half the water held at field capacity has been lost (the ‘wilting point’). The difference between the field capacity and the wilting point is the ‘available water capacity’ (AWC), and is hugely variable; it can be four times higher in a sticky, heavy clay than a coarse, light sand. As well as water, clays also hang onto nutrients better, making them potentially more productive than sands – but also more prone to waterlogging and structural damage, harder to create a fine seed bed, and
generally harder to manage. Clay-land farmers refer to sands as ‘boy’s land’. The sweet spot is a sandy clay loam which has a mixture of particle sizes (large sand, through silt, to very fine platelets), combining their best qualities.

Too much info? Actually, that is a gross simplification. You could spend a lifetime studying soil and still be ignorant. Though its physical makeup is important, farmers’ management of the soil also has a massive, long-lasting effect. Adding organic matter, particularly stable and mature compost, can, over years, increase sands’ ability to hold water, and make clays easier to manage by stabilising the structure. Increasing the organic matter in a sand from 0.5% (typical of an over-cultivated, chemically fed arable sand) to 3% (more typical of well-managed sand in an organic rotation) could double the AWC, allowing crops to thrive well after they would have wilted. The impact of good soil management is huge – not just in agricultural productivity, but also in reducing flooding, fighting climate change through sequestering carbon, controlling water pollution and increasing biodiversity. Organic farmers are well ahead, but conventional farmers are starting to get interested in proper soil management too. Perhaps, after half a century, we have finally managed to show them what is possible.

Guy’s news: Why I do it organically

I admit it; I farm organically largely because it just feels right. Is that an admission of weakness? I have a science degree, my tractors use GPS, and I wholeheartedly embrace the IT revolution. But I still find that what feels right is a good aid to making good decisions. Some condemn being guided by emotion as weak-minded, muddled thinking – which it sometimes is. But over the 30 years since I started farming organically, much of what felt wrong in farming has turned out to be wrong for very tangible, logical and scientific reasons.

Decisions that don’t use what feels right as a sanity check can be just as dangerous as emotional decisions made without checking the measurable evidence. I do have concerns about selecting evidence to support a predetermined emotional bias, but what brings me back to the debate and makes me such a big mouth is frustration with the far more pervasive tendency to select evidence to support a commercial bias; something our agrochemical industry are masters of. Take the example of the ‘world’s favourite herbicide’, glyphosate. In my early days as an organic grower I really missed glyphosate, which kills every part of the weed without the need for costly, soil-damaging ploughing. Given a free rein, my own standards would have included the occasional use of glyphosate, had I not been restrained by organic rules. But I would have been wrong. I am retrospectively grateful for what seemed like an illogical, perhaps emotionally-driven restraint at the time. There is now strong evidence that glyphosate is safe neither for users nor for the environment, and debate rages in Europe over whether it should be banned.

History has told this story again and again – so-called ‘safe’ pesticides are later banned. To be organic sometimes feels extreme, even provocative to chemical-using neighbouring farmers. Yet I am confident that time will reveal the ‘extremists’ are not the organic farmers, but those who use mindbogglingly toxic chemicals with such casual abandon; that science will justify those who embraced ecology, rather than those who exploited incomplete knowledge of how to disrupt life without the humility to appreciate the risks.

For those with the time and interest, please see for an extended version with references.

Guy’s news: Northerly winds, love & Wendell Berry

The new growing year has started with a blissfully dry and bright spring and no major gales, frosts or pestilence. Night time temperatures have been low with a few frosts, but nothing damaging. Most crops were planted into perfect seedbeds and are doing well; a few are even ahead of schedule, helped by super-light (just 17g/m2) fleece crop covers which retain moisture and keep off the recently prevalent northerly winds. The swallows have only just arrived, a month later than last year; presumably delayed by those dry winds.

With so little to moan about, let me instead recommend those with time to listen to an exceptionally good Start the Week on BBC Radio 4, titled Wendell Berry: The Natural World. Andrew Marr interviews the delightfully drawling 82 year old poet and Kentucky farmer, along with the environmentalist Paul Kingsnorth and economist Kate Raworth. The discussion was marked by a refreshing humility and refusal to bow down to the “grown up” notion, prevalent in economics, politics and neo environmentalism, that the world can only be measured in, and be guided by, hard numbers. Above all there was an acknowledgement of love; if we can’t admit to loving our surroundings, whether people, nature or food, how can we care for them? Love, often written off as a childish, romantic or unaffordable emotion, actually provides a more powerful motive to care for what we value than the fiscal incentives favoured by economists and politicians. Despite Berry reading perhaps one of the most depressing poems ever written (which he quickly and endearingly acknowledges), I urge you to listen. I suspect as a society we need a few numbers to check our more outlandish emotions, but I long for a world shaped by love over one which denigrates the unmeasurable, and will fight for it unashamedly in the boardroom, in my fields and in this newsletter until my dying breath.