Should gardening be evidence based?

As clear as mud

I keep reading it should be and then find myself informed of  a research finding I think inappropriate. Why should my hackles rise when evidence based action in life is my fundamental philosophy?

An alternative expression of the importance of evidence is it should be supported by experimental data or that horticulture should be science based.

I think my problem is that evidence is frequently flimsy and often contradictory. Not just in gardening but through the world over.

I spend hours avoiding 'fat free products'

Where excellent research has been done in fields such as health and nutrition it is usually overlaid by misreporting, wrong conclusions, special interest lobbying, propaganda and fear of litigation. How often do I read a report of good science interpreted by a none scientific journalist whose account is littered with repetition of fashionable dogma. Even scientists themselves sometimes seem to say “my research points another way but carry on eating fat free food and taking the statins” 

Much good science is lost for the sake of a cheap headline or company profit. Much is rejected because it does not sit with established belief.

Reasons to be cautious

I sometimes lose confidence in horticultural research for the following reasons.

1. Much research is of poor quality. It is frequently done with insufficient duplications, very few safeguards and is statistically invalid. However feeble it may be, it is often represented as fact on the net! Worse it is inflated and republished by vested interest.

Insights come from very simple things

2. Although excellent insights worthy of further investigation often come from very simple trials carried out by inexperienced or ‘narrow’ researchers it is premature to proclaim it as fact.

Peter likes to see for himself

3. Much research is carried out with vested interest in sight. Scientist Peter Williams says before I believe it I should ask who is paying. Ask the right research questions and you get your required answer. If the answer does not suit you there is no legal requirement to publish.

4. I fear much research is contradictory and cannot be repeated by others.

Many professional composts are honed to grower's needs and are unsuitable for the gardener. Many amateur's composts are just rubbish

5. Components of gardening knowledge comes from a vast diverse range of specialist fields such as agriculture, commercial glasshouse production, market gardening, ecology and garden centre trade - and that merely scratches the surface of numerous fields of endeavour and their subsidiary components. I have always considered there was much transferable knowledge between them but unfortunately precise research is honed to a sector’s individual needs.

6. Gardening is so diverse and there are so many variables such as the crop, soil, weeds and climate. Such criteria might change from day to day, season to season or one place to another. 

It makes me happy

7. What is a gardening measure of success? Is it beauty, yield, profit, labour saving, producing pristine produce, supporting the environment or personal satisfaction? Every gardener’s needs are different. To me the measure of success is to be happy and healthy even though to critics a gardener’s methods might not pass muster!

8. And of course many so called facts are supported by no evidence at all. There are few restrictions on gardening product claims

A more positive view

There is high quality gardening information out there and without unbiased investigation where would we be? My own personal view is that a knowledge of biological sciences helps you sort the wheat from the chaff but then some of the best gardeners I know have no science at all. Gardening takes its adherents from diverse fields of endeavour.

In my youth I got even more satisfaction than now from gardening and perhaps made my best garden when I had no technical knowledge at all. 

Here are a few suggestions how to build up gardening knowledge

1. Initially devour all gardening reading you can, but learn to question its provenance. Is it written by a hack journalist who has trawled the literature or a gardener writing from genuine experience?

I try something different with my tomatoes every year

2. Go beyond the level endlessly recycled by gardening television and gardening magazines. It’s often good stuff but after a couple of years you will have heard it all before.

Decent gardening courses are rare and college extension none existant

3. Listen to gardeners within their own specialist fields but don’t let your respect for them blind you when they spout nonsense about things like bonemeal. They too have grown up with recycled information.

Read related science

4. Read about plant related things from diverse sources and in your mind file them away

5. Be suspicious of so called gardening experts. Some of the best gardening knowledge resides with amateurs who have followed their own passion. 

6. Search out information on the net but duplicate your sources to take in diverse opinion and filter the chaff. A sound source of advice is ‘gardening extension information’ published by states in the US and Australia and no doubt elsewhere. Dare I promote the RHS despite their sometimes sloppy journal and their extreme PC?

You can water at any time of day

It's a juicy centipede

Large cut nicely healed at the edges after a year

7. Most gardening myths are harmless and an endless source of amusement. Never the less they are sometimes seriously wrong. Blogger Robert Pavlis will debunk them for you. The ‘Garden Professors’ blog is a good independent source of ‘gardening extension information’ (Something sadly lacking in the UK). I fear the professors rely excessively on so called evidence base.

What on earth?

7.Try things out yourself and always be ready to move on in your methods. Unlearn your early lessons. My own gardening is never the same from one year to another. In my opinion too many gardeners do things precisely the same way every time!

8. Break the rules and find ways to be a better gardener.

There are so many exciting things in a garden

Every year brings new challenges

Four gardens, three soils, same drought… and how did none diggers fare?

The higher parts of my garden are starting to suffer

The lower and wetter parts of the garden with zero watering fare somewhat better

This post like Topsy this has grown - unlike some of our plants. There are issues of people and soil type but also those of how a soil is managed and it’s a long time since I tried to persuade you minimum cultivation is best. It has to be a two parter. Here is Part 1

My annual mixture sown on my former vegetable garden in April when the soil was fully charged with rainfall has had no watering at all

Today I focus on four gardens and three soils. Mike and Isobel have recently downsized from a large house and a huge garden. They have suffered the heaviest of clay soils and you can imagine their initial, now regretted, delight that their new house in Upper Poppleton is on sand. A genuine sand. The kind that ticks all the boxes of popular gardening lore, it holds little water and is sharply drained. Dig down a spit (ugh) and you get to pure sand (ugh). 

They have already discovered that if you water a drought established plant in settled soil their water runs sideways and does not sink in like their previous well managed clay. Welcome to soil hydrophobia, that phenomenon where really dry soil repels water (not to be confused with dry puddled clay that is hard as a rock).

They are starting  to treasure the clay soil in the huge number of potted plants brought from their old garden. They can’t go back for more.

My own soil texture is on the borderline between silt and sand. Around here we constantly argue whether it is coarse silt or fine sand. Soil scientist Peter Williams assures me we both have coarse silt and we both agree it is an alluvial deposit of the river Derwent which thousands of years ago meandered our way. When I dig down deep I get to pure sand (er, silt). If I dig a metre or more I get to pure clay (Never done so but the name Brickyard Farm down the road gives a clue). My clay provides a deep basin that holds water. Wonderful now but not ten weeks ago when the lower parts of my garden were still flooded. The high parts of my garden at present are horribly dry.

My silty soil suffers from hydrophobia too but its fine texture ensures that when thoroughly wetted as in my pots, tubs and planters it is very water retentive and needs less frequent watering than any modern compost.

Peter down the road is a borderline digger. and makes most of his seed and potting compost from decayed grass and Autumn leaves)

Surviving the drought

We have already resorted to a directed hose pipe watering on these dahlias

After endless rain up to eight weeks ago the proverbial meterological tap has been turned off and we have had zero rain for eight weeks now. Worse the temperatures have been high, the air has been ridiculously dry and even on cooler days it has been windy. Peter observed dehydration in the wind  has been worse than in sun. You can almost see the water level in my ponds plunge.

We visited Mike and Isobel last week. Their plants were wilting and the yellow lawn crunched. Not only have they for the first time suffered a water meter they now find that water pressure in Upper Poppleton is miserly low. 

Outside their front door was a huge pile of excavated bone-dry yellow sand destined to be used in a new border. I suggested it might be ameliorated with the wood chippings from some recently felled trees. Best of a bad job.

Isobel’s March planted beech hedge has needed a furrow to be laid alongside it to retain water and is needing twelve gallons a day. (I don’t approve of the frequency, better less often and more each time and in total less)

Peter too suffers a water meter. Apparently water is about £3 a square metre. That’s 0.3 pence a litre. (Published water rates are as opaque as the prices of other utilities and my figure includes the 95% estimate of water volume wastage that is deemed as the effluent cost)

Each of my ten litre tomato pots in this weather needs 2.5 litres of water every second day

I did a back of the envelope calculation and if I were on a meter my Shirley size tomatoes would each cost almost a penny each just for the water. Worth every penny!

Peter has a small nursery to irrigate. Like me he does not generally water established plants in the ground. He has broken this rule for notoriously shallow rooted rhododendrons and azaleas.Without water many of these plants would die  Last time I called he was watering away.

I have taps that run off each side of the house. I also have a rather ‘Heath Robinson’ eight inch deep buried hose that when turned on for a few minutes fills a 15 gallon tub next to my greenhouse. None diggers get away with such stupidity and Brenda constantly moans. I only use this tub when I want the odd can-full of water.

My long watering run is delivered by 50 metres of hose. I use a much shorter length for our small courtyard. I have a total of about a hundred tubs and planters and in addition there is my greenhouse and a small nursery around it. Within the stretch of the hoses are several drought prone plants that intermittently get a generous splash. In this weather a full run takes well over an hour and is needed every three days (two days in the case of the tomatoes which are in ten litre pots of my soil/char compost). 

Unfortunately in this weather my small raised rock features need regular watering

I prefer to water in the morning when the pressure is high.

Brenda walked around in disgust last week and claimed she found several plants dying of drought. She spent several hours carrying out emergency watering. All the azaleas perked up but at least three shrubs are now on emergency watch. 

Two identical blueberries, one has succumbed to drought and is now in convalescence (watering and pruning)

Despite the above evidence I almost invariably find that after a drought is over that although many established plants might have not performed well they always survive

I will let the pictures do the rest of the talking

Triple whammy

My formerly elegant evergreen coronilla suffered deep root death in the Winter wet, was stripped of its foliage by the beast from the east, was starting to recover and then came the drought. Who would be a gardener?

Hostas and ferns on my watering run

I am in trouble if I miss the bird bath

My zantedeschia must have very deep roots into the soft silt, it has had  no watering at all, nor has the clematis

Not all the pots are big ones

Although begonias do quite well in shade this one grown in full sun has made four times the growth of plants bought at the same time grown in shade

No watering here

My ground cover of as yet un-mown chewings fescue retains its colour very well (and I have now collected fresh seeds for elsewhere)

Survivors

Flooded for three months this Winter these moisture lovers are still happy although the gunnera is half its normal height and off picture the astilbes are severely wilting.

Part 2 of this post will appear in August and will be a little more specific with regard to minimum cultivation. It will also record what happens next. There will be pictures of Peter's garden too.

There are no links at the moment. If any of my comments tickle your fancy please interrogate my search box. You will be surprised what you find

And as I publish today still no rain

Brenda restores son’s garden

Brenda sorts out a garden in France

The bee's knees

As far as I was concerned I would be watching the ‘footie’. It might be our last visit and the house to be possibly sold. No incentive to yet again do the garden.

Never a gardener Peter had been too busy to apply tender attention. It was severely overgrown. In fact it was completely out of control.

Brenda foolishly volunteered to tidy a couple of borders and finished up doing the whole of the near garden dragging me in and shaming Peter into heavy lifting

A right mess

Some gardeners tell me they get immense satisfaction from transforming an overgrown piece of garden. Such an approach is anathema to me. Whilst giving a small plot micro attention the rest of the garden is going to pot. Weeds grow luxuriantly and plants outgrow their place. By the time you get round to it massive weeds take over and need removing starting that sad cycle of denuding the soil by carting to the compost heap (on a good day, otherwise the tip) and in due course after much hard work composting (and again on a good day if you remember) returning your compost back to the garden.

I preach that the approach to garden maintenance should be little and often. A soft touch regularly made. Weeds recycled in situ and soft prunings returned direct to the ground. 

I prefer when I carry out maintenance that nobody notices. You can imagine the scathing retorts I get from Brenda. I have developed a very thick skin.

Probably unworn since our last visit two years ago we slipped on our boots with some intrepidation

This report gives you a few snapshots of a (fairly) busy week in France 

Talk about a mosaic hedge!

This is the good bit of the hedge! Off camera there are long stretches of dead box. I have previously reported the deadly invasion of box caterpillar. These small box plants were killed by a single infection. Larger box were finished off elsewhere by their second advance 

Peter had a good wheeze to extract the dead box 

Compared to pulling the horse box this was a day off for the car

It worked really well

Setting about the border

Do those gloves match?

Oh la la action lady dances on the wisteria

The wisteria had been running at a mile a minute, horizontal over the ground

Vertically challenged

The botany books when listing the functions of leaves usually omit to mention leaves are a weapon to compete with neighbouring plants. The gardener acts as adjudicator with light touches on the tiller. Here the canna if left to its own devices would completely swamp the day lily (and Brenda).
Both the canna and the hemerocallis are residents of the original, even then overgrown garden. I have replanted divisions all over since they moved in.

Job well done and path can now be navigated

Those bamboo shoots which were too thick for the loppers were cut with a saw.

Peter is starting to worry that the black bamboo I had previously propagated from an already resident plant is going to take over

A lovely smoke bush - round at the neighbours

Links to my earlier posts about Peter's box caterpillar
The plague originally descended in 2015. Considering continued reports of it appearing in UK gardens the post has proved to be quite popular

I have now had to update my post about the hedge's recovery considering today's report of its demise. I have changed my opinion as to whether to remove it

The pleasure of spraying

Ten days after my first and only visit
Thank you Iris for the pictures

Today I try to persuade you of the advantages of glyphosate and to direct you to my articles that explain how to spray.

I was almost singing and had a smile on my face. It was a fine sunny morning. I communed with my garden and the birds were singing. I was wearing a knapsack sprayer - half filled these days.

Not as anyone who has been on an official spray training course might imagine vigorously pumping away and walking in straight lines. Just a gentle meander intimately at one with my plants. A gentle pull on the trigger here and there. My hand in my pocket to reduce the temptation to squirt with too much pressure, almost relying on gravity flow.

My long lance almost kissing the ground. Few new weeds to be sprayed, barely sufficient to keep the gentle flow going. Close concentration, making small decisions, noting jobs to be done and delighting in my healthy plants.

The thought occurred that I should share with you my joy especially those of you who might imagine spraying stressful or even a sin. Being a warm Spring day there were just a few more weeds than usual and it took all of two hours to spray every last weed in the whole acre of my intimately planted garden.

When the next day I was spraying in Bolton Percy cemetery and a visitor remarked my efforts looked very relaxing it reinforced my decision to tell you.

It was the most healthy and vigorous couch grass I have ever seen

Iris’s two octogenarian friends have a new allotment and she enrolled me to give them a starting off spray. She shares with them several neat lovely weed free beds but the overall surrounds of edges, paths and under the soft fruit were overrun with vigorous luxuriant weed. It included the most vigorous couch grass I have seen for a long time. A relic of a previous owner unable to cope and who had inadvertently propagated couch as he tried to extract it. I am confident that my single spray will completely eliminate it - its condition was so receptive in its intact luxuriant condition. Such an easy weed to control if you do it right.

As a ‘half size allotment’ there was perhaps a hundred and fifty square metres of weed. Unfortunately a light wind was getting up, perhaps 10 mph. Just safe to continue.

For such an area I needed a little more pressure, perhaps two or three intermittent pulls on the handle. My cone nozzle pointing firmly down the spray was released about three inches over the weed as I hoovered around. It took all of five minutes and ten minutes later we were back for a coffee. I remembered to shuffle my wellies on soil before walking away on the grass path.

The vigorous rhizomatous grass was completely killed under the raspberries. I am told a very fine crop is well on the way now

Although most gardeners and almost all garden  professionals are happy to use glyphosate on new overgrown sites and continue to use it on such as paths, open spaces, under hedges and and in the time between one successive crop and another very few dare use it as intimately as I do between clumps or individual plants. The very thought of even minutely damaging a plant with glyphosate is taboo and not on their radar. (They will kill with abandon using spades and similar but that is alright).

Six days after spraying, not yet dead but well on the way. Note that on the distant allotment the couch is invading the mown path. Hence the yellow edge where I killed it as my client requested

I just have to accept that for various reasons my methods just don’t wash with most gardeners.

Although the press beat a path to my door thirty five years ago when my cemetery garden in Bolton Percy was created and my methods of managing large floral landscapes with levels of labour that were way off the bottom of traditional scales, I know nowhere else similar large areas so managed. Other than my own!

Now I have ceased to spray and maintain the Cemetery garden at Worsbrough I fear how they will manage.

On the other hand Bolton Percy churchyard is in good hands and the cemetery team already do a limited amount of spraying. Indeed they have persuaded me to continue a few visits a year to ensure the weeds do not get out of hand.

Peter Williams has a new project

Regular readers might now have discerned that other than gardening I am not very good with practical things. Some doubt the gardening too. 
When Peter Williams offered to trade me my handyman jobs if I would do his spraying I jumped at the offer. 

He admitted that although he had zero reservations about spraying he found it a burden.

Peter's nettles had got out of hand amongst the raspberry canes

Already in his debt for mending my tap and repairing my pergola I was down the next day. My first task was to spray his hard surfaces and to sort out the overgrown part of his nursery. Always complementary he expressed surprise at my accuracy, boldness and speed. He declared amazement at how little spray I actually used. 

Wonder whether he will think the same next week?

Not only nettles and brambles but a rubbish dump too

I had intended to report my second visit to Peter to spray his overgrown wood. My efforts have so enthused him he is starting a new project making a wildlife garden. I will be back there many times! In a few months time it will make a post of its own!

See the brambles high up in the trees

One spray clobbered these brambles. New growth (after strimming) will need another spray in six weeks time

After a week the nettles were starting to die

Dozens of scrubby trees have to go including this one girdled by a deer

The man himself

Links to my major glyphosate posts
I have tried on my blog to leave a series of posts that describe my unorthodox methods. Nothing is original and one way and another all work and are successfully used by others. I have a lifetime experience spraying in gardens and hope many gardeners have learnt something from what I pass on.

My object today is to tie together links to a few of my better efforts.

Roundup is not selective and does not discern between a plant and a weed. You provide this and it is called selectivity. The main elements of selectivity are direction of spray  and timing.

Relevant to timing is that glyphosate is particularly useful in winter.

Impatient gardeners think glyphosate slow when it takes weeds several days for weeds to die. I explain how glyphosate is quick.

I wrote here how Marie, a relatively inexperienced gardener could significantly speed her weed control by investing in a knapsack sprayer.

Although several posts have examined projects where a new garden was created on weedy areas - notably Lyndi’s field and Cathi’s grass verge - this was an instructive early post about clearing the village plot.

Although most of my projects use glyphosate almost exclusively for weed control my actual philosophy at home is that the best approach to weed control is little and often and in the round using all available methods. I like to ring the changes in my own garden. Today is dry and windy and I will be out hoeing