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Myths - what you don’t need to do

If you learn just one thing from this lesson, may it be to question things which you feel don’t make sense. I call them myths or misunderstandings, and they are common. Worse, they are often perpetrated by people in positions of authority, or those who claim superior knowledge.

Positions of authority do not automatically result in true statements – I am not wishing to be critical of anyone, just saying how it is. I feel that more of us need to ask the questions which our hunches suggest, in order to move forward our understandings and methods.

I received this comment on YouTube from Daniel Foster on 10 February 2019, commenting on my Myths video:

‘I have been gardening/growing/advising for nearly forty years and I wholeheartedly endorse what you say. By coincidence, I also grew an excellent crop of parsnips that season (2016) on ground where I had applied a thick mulch of compost and manure. As you say, the tradition of inventing myths, over-complicating things and making lazy assumptions is also true in other aspects of life. It’s all about disempowering the public, so the “experts” can create an easy role (and career) for themselves. Whereas real experts (like you) actually build peoples’ confidence, encourage them to learn from their own observations and trust in their own instincts.’

I want to build your confidence through understandings that work. This may at first seem odd, because many misunderstandings are deeply rooted, to the point that you may think ‘surely that can’t be wrong’.

We need to search a bit for the origins of established beliefs, to understand the confusions and extra work they cause. Digging is the main myth, and many others are related to it – crop rotation for example.

Myth 1 – Crop rotation in farming

Much advice on rotation states that an interval of four years is needed between plants of the same family, to reduce disease and increase cropping. This dates back to the 1730s and the work of Charles ‘Turnip’ Townshend on his Norfolk farms – not gardens. He copied and developed a method already used in Holland.

Townshend replaced a fallow year, in the traditional three year rotation, with fertility-building clover, and added turnips to make it a four year rotation. This increased total output and enabled farm animals to survive winter, without a large slaughter every autumn.

Both the clover and turnips were food for animals, in this case mostly sheep, whose droppings and manure added fertility. This practice was soon widely adopted by farmers, and productivity increased overall.

However, through the last hundred years, the goalposts have moved significantly. The use of synthetic nitrogen fertiliser has diminished that original need for the fertility provided by clover and animal manure.

You could practice a four year rotation if your garden were large enough to accommodate clover for a year. However, vegetables require greater fertility than field crops, and yields from such a system would be low, in proportion to the time spent preparing ground: planting, weeding, picking and clearing. Townshend’s method was for farming in fields and with animals, not for gardening.

1. All these are root vegetables, but they are from many different families
These are all root vegetables, but from many different families
1a. April, broad beans 4th year consecutive in same bed and potatoes planted to their right, also 4th year same soil
April – the fourth consecutive year of broad beans in the same bed, and potatoes have been planted to their right (also the fourth year in the same soil)
1b. 1st June and the Aquadulce beans, from home saved seed, are almost ready for a first pick
1 June – the Aquadulce beans, from home-saved seed, are almost ready for a first pick
1c. October and cabbage have followed beans, leeks have followed potatoes, 4th year consecutive
October – cabbage have followed beans and leeks have followed potatoes, in the fourth consecutive year

Myth 2 – Crop rotation in gardening

Rotation theory for vegetables emphasises a categorisation of plants into families or groups, to reduce disease and make the most of limited fertility. Families and groups are not the same, and this leads to misunderstandings.

I often read that ‘root vegetables’ are one group of the four years, but this makes little sense in terms of avoiding disease, which is linked to family characteristics such as late blight of potato and tomato. All of the roots and tubers in the first photo above are from different families, and are not related:

  • Carrots are umbellifers, as are parsnips, salsify and scorzonera.
  • Kohlrabi is a brassica, along with swede, turnip and radish.
  • Beetroot are of the beet family, related to chard and leaf beet.
  • Garlic are alliums, like leeks and onions.
  • Potatoes are solanums, related to tomatoes and aubergines.

If anyone mentions ‘root vegetables’ as a category in rotations, take the rest of what they say with a pinch of salt. They may be using that category because root vegetables are sometimes called ‘light feeders’, which makes little sense for soil’s hungry organisms. We feed the soil, not the plants (see below).

To finish with a caveat, that if you are unlucky enough to take over a UK allotment whose soil has been abused by over-cultivation, you may inherit soil diseases like clubroot, and need to practice a rotation. No dig and surface feeding will help soil to heal, but it will take years, rather than months, for the problems to reduce as soil life recovers.

Myth 3 – Feeding plants

An aspect of rotation advice is the categorisation of plants into ‘heavy’ and ‘light’ feeders. This has some traction if you rely on synthetic fertilisers and like making calculations (see Lesson 14), but for anyone using a no dig approach – with organic matter to feed soil life – it makes no sense. Soil organisms are alive, and need food and water in the soil. You can turn a blind ear to anyone talking in terms of not giving compost for ‘light feeders’.

Compost is not fertiliser in the usual sense of the word, as in nutrients for a particular planting. The nutrients in fertilisers are mostly water-soluble and readily available. In contrast, compost’s array of nutrients are held in a water-insoluble state, until plants need to access them. They are also eaten and excreted by soil life, which converts them into a wider range of food options for roots.

This contradicts advice such as ‘don’t give compost before sowing carrots or you will have more leaf than root’. This statement shows a misunderstanding of what compost is, and assumes it has free nitrogen which will flood the soil (as soluble fertilisers do) and cause leaves to grow more than roots.

As we saw in Lesson 5, there are farmers and gardeners who believe in the opposite of rotation, and call it continuous cropping. They consider it an advantage to soil and plants. My feelings are between the two: that it’s good to leave at least half a year between plantings of the same family, but without a need for intervals of two or more years. Especially with healthy, no dig soil.

Myth 4 – Compost ‘fertility’

I often read that ‘green/garden waste compost has no fertility’. This is such a bald statement. For one thing it’s massively vague, and we need to know what is meant by fertility. Nutrient levels are actually often good, although release slowly.

The organic matter is food for soil organisms, which then make nutrients available to plants. In addition they improve structure, another and vital aspect of fertility. A common thread of mythical statements is an isolation of one aspect, without considering the whole picture.

Myth 5 – Roots

2. Roots like firm conditions so I tread compost when filling a new bed, also see lesson 16
Roots like firm conditions, so I tread compost when filling a new bed – this was for onions (also see Lesson 16)
2a. January 2013 and this soil has been squashed by a dumper truck - what to do?
January 2013 – this soil has been squashed by a dumper truck, what to do?
2b. I waited for it to dry, levelled it with a a spade, scattered grass seed and 1cm compost
I waited for it to dry, levelled it with a spade, then scattered grass seed and 1 cm (0.4 in) of compost
2c. By summer the soil’s bad condition is only a memory, with minimal effort needed
By summer the soil’s bed condition is only a memory, with minimal effort needed

There is a common misunderstanding that ‘plant roots need loosened soil to root in’. To the point that even some no dig gardeners say you should ‘never walk on the beds’. During courses at Homeacres I make a point of walking on a bed while explaining this, so that participants can see how I don’t sink in, yet how the surface is springy.

I suspect the manufacturers of rototillers, for pushing the belief in loose soil on gardeners! The strong growth of plants in no dig gardens is strong evidence to the contrary. The structure  of no dig soil is firm, yet with a matrix of air and moisture channels, created and maintained by life in the soil.

Even that sea of mud at Homeacres, in winter 2013, did not move me to dig or fork the ground. I did make a hole with a trowel to have a look, and found that the soil was still undamaged below the top layer, 5–6 cm (2 in), of damaged soil.

It’s a heavy soil here, and the dry winds of March initiated cracking, which allowed entry of air. Then, in April, I levelled the surface with a spade, scattered grass seed, and spread 1 cm (0.4 in) of compost.

By June, the combination of worms feeding on the compost near the surface, plus new roots of grass, meant that this soil was on the way to being restored. Far more quickly and easily than if I had tried to aerate the soil myself.

Myth 6 – Tree planting

3. Tree roots need only a small hole at planting time, no larger than their roots: these are one year maidens
Tree roots only need a small hole at planting time, no larger than their roots – these are one-year-old maidens
3a. By their second summer there are strong branches, all from the stick-like trunk of 18 months earlier
By their second summer there are strong branches, all from the stick-like trunk of 18 months earlier
3b. The mulch and new growth in their third summer, the apple trees are healthy and cropping
The mulch, and new growth in their third summer – the apple trees are healthy and cropping

Take it from me (and check the photos above for confirmation), your trees will benefit from their roots needing to push into firm soil. This is what they have evolved to do, and the firm soil is an excellent anchor for stabilising trees in wind.

Ignore anybody who says you need to make a larger hole than the roots of your tree. Another time saver is that these trees have never been staked, including those on M26 rootstock, which often has a stake recommended. The RHS advise permanent staking of trees on M26 rootstock, and five years of staking for MM106.

The only trees I stake are the small ones, on M27 rootstocks, which grow shorter roots and risk falling over when fruit grows heavy. No other Homeacres’ apple trees have ever had a stake, and are exposed to the prevailing SW wind. This can blow strong, because there is not much between us and the Atlantic ocean, 50 km (31 mi) to the northwest.

Another piece of unhelpful advice I hear is to backfill planting holes with some organic matter, to ‘feed the roots’. This goes against how nature works, with roots and soil organisms feeding near the surface and soil fertility building from above. Keep your organic matter for surface mulching, where it also helps to reduce growth of weeds.

Myth 7 – Compost for potting

4. You can sow and plant into nutrient rich compost, the tray on right is 18 month cow manure, on left is multipurpose potting compost
You can sow and plant into nutrient-rich compost – the tray on the right is 18-month-old cow manure, the one on the left is multi-purpose potting compost
4a. Spinach sown in both trays on the same day is stronger in the cow manure on left (14.3.12)
Spinach sown in both trays on the same day is stronger in the cow manure on the left
4b. Comparing growth of kale in double strength compost left, and my normal multipurpose right
Comparing growth of kale – in double strength compost on the left, and my normal multi-purpose compost on the right

I often read expressions of worry over using different composts, according to the stage of growth. Even compost manufacturers baulk at seedlings growing in their higher-feed composts – part of the reason for ‘seed composts’, which have fewer nutrients than potting composts. The other reason for using seed composts is better drainage.

I have sown and pricked out into Levingtons MP3, just to see – it’s one of the most nutrient-rich composts available. Seeds and seedlings grew fine, just as they do in cow and horse manure, which is often claimed to ‘burn seedlings’.

This might happen if the manure were fresh from the animal, but no sensible gardener would use such a manure. The ‘burn seedlings’ claim puts a lot of people off using great compost! It even pushes them to use mixes with soil in, which often results in weaker plants, less air in the mix, and more weed growth (see Lesson 15). The main time that I make a distinction between composts for sowing vegetable seeds, and those for growing on, is when I use them for basil or lettuce. I find that these germinate best when drainage and air levels are high, so I mix 50% perlite or vermiculite with my normal potting compost, especially for basil.

For propagation, just purchase one batch of potting or multi-purpose compost (called potting soil in the USA ), and have some vermiculite or perlite available to add to the compost when sowing lettuce and basil.

Myth 8 – Compost heaps

5. Compost heaps can have solid sides!
Compost heaps can have solid sides!
5a. Homemade compost 3 months old, made in a heap with solid sides
Homemade compost – three months old, and made in a heap with solid sides
5b. You can add blighted material to compost heaps, and perennial weeds too, see lesson 17
You can add blighted material to compost heaps, and perennial weeds too (see Lesson 17)

It’s often said that compost heaps need slatted sides to ‘let the air in’. Yet have you ever wondered how much air can flow into a solid heap?! From what I have seen, very little does, and instead what happens with slatted sides is that you find there is:

  • A loss of moisture at the edges
  • Reduced warmth near the edges
  • Some regrowth of weeds, from any roots finding light at the edge

If your heaps are enclosed by pallets, I would line them with thick cardboard. This will last a few months, long enough to benefit the fermenting heap (see Lesson 13 for more about this).

Myth 9 – The three sisters

I am often advised to use this easy method of intercropping. However, in the UK, it’s mainly by people who have read about it, not practised it, and who have not understood the reasoning. I had the following comment from Linda Pankhurst, who took this course online:

‘I want to comment on your statement about how myths proliferate. Years ago I tried the “Three Sisters” method of growing squash, beans and sweet corn in the same bed to benefit all three. Apparently the Native Americans in the US did this and the early US settlers copied it with success.

The theory is that the beans can climb the sweet corn stems and the squash sprawl about covering the ground, suppressing weeds and keeping the ground cool and moist.

What they don’t tell you is that the beans climb up the sweet corn and wrap themselves around the cobs as they form. When you want to pick the sweet corn you have to unwrap the yet-to-crop bean stems…..sacrificing their harvest because the stems always snap. And you can’t actually get at any of the crops properly because you can’t walk on all the squash growth.

What the gardeners who preach this have failed to think about, is that the Native Americans and early American settlers were using all three crops as winter food, leaving them all to grow to full maturity in situ and taking the whole crop at once in autumn, once the foliage had dried. Squash and beans were to store for winter and the corn was also to harvest when dry, to grind for polenta or to feed the whole cob to chickens.

Those who advocate this method often wouldn’t if they had tried it. We don’t usually leave corn to go hard, and we like the beans young and fresh.’

In the UK I have had success with ‘Two Sisters’: sweetcorn for fresh cobs between winter squash. Transplant both at the same time, with the squash 1 m (3 ft) apart, and one or two sweetcorn plants between each squash plant. Unfortunately, I can’t practice this at Homeacres because badgers eat the corn and make a mess in the process.

Myth 10 – Reverence for the Victorians

6. We inherited many myths from the Victorians, such as melons needing support as they swell and ripen
We inherited many myths from the Victorians, such as melons needing support as they swell and ripen
6a. These module trays have been used 5-20 times without ever been cleaned, that myth comes from the days of clay pots
These module trays have been used 5–20 times, without ever having been cleaned – that myth comes from the days of clay pots

In the UK, in particular, confusion arises from the misplaced esteem given to methods of the nineteenth century, especially the fine gardens of wealthy aristocrats. Their methods were and are copied, without appreciating that they were based on a lot of cheap labour and a desire for perfection to please the owners.

  • Those much admired hotbed pineapples cost around £5000 each in modern day wages, because of all the time needed to keep filling and emptying the pits providing warmth.
  • You don’t need to wash or even brush pots or trays between use – I don’t, and my plants are healthy. This misunderstanding maybe arises from the use of clay pots in older times, and indeed clay does need more cleaning than plastic because plant roots enter the clay if left in there, making the next plant difficult to tap out.
  • It is often recommended to support melons on cordon plants with a net. However, I have grown hundreds of melons of decent sizes, without ever supporting them.

Myth 11 – Store root vegetables in sand

This is another aristocratic leftover, misleading so many and causing unnecessary worry and expense. When packed in sand, root vegetables keep very nicely – but it’s not obligatory.

If we have any root vegetables that we don’t plan to use within the next two weeks, we place them in crates, boxes or sacks. There is no sand, but a little soil remains on the roots from when they were harvested, and they live in a damp shed.

A root cellar would be necessary in cold climates to prevent the freezing of roots, especially potatoes. Other root vegetables can survive slight freezing, and store well in a temperature range of 1–10°C (34–50°F).

12. Vegetables store well in boxes, crates and sacks with no need for sand
Vegetables store well in boxes, crates and sacks, with no need for sand
12a. Potatoes from a sack in my shed on 1st May, just need the shoots rubbing off before washing and cooking: harvested August
1 May – potatoes from a sack in my shed ; the shoots just need rubbing off before washing and cooking (they were harvested in August)

Myth 12 – Hardening seedlings before planting

7. Save time by not hardening off, use fleece instead: these plants came straight out of the greenhouse
Save time by not hardening off – use fleece instead; these plants came straight out of the greenhouse
7a. Fleeced beds are all planted and sown, but during April I keep the fleece on top of seedlings, this was a -3C/27F morning
Fleeced beds are all planted and sown, but during April I keep the fleece on top of seedlings – this was a -3°C/27°F morning
7b. After warmer weather arrived we removed the fleeces and this is just 16 days later
We removed the fleeces after warmer weather had arrived – this is just 16 days later

A significant time waster is the advice to harden off all greenhouse-grown plants before setting them in the ground. At Homeacres we plant straight from the greenhouse, even on cold days of say 5°C/41°F, though I prefer it warmer!

An exception is if I need space in the greenhouse and am not quite ready (short of time or space) for a batch of plants, so they live on a table outside for a few days.

Courgette plants need warmth to grow, and once I took some straight from the greenhouse and transplanted them into ground which still had ice on, from a late frost. It was May and warming fast; these plants grew just fine, with fleece laid on them for the first ten days.

Fleece (row cover/reemay) helps a lot, and there is no need to lay it on empty beds before planting, supposedly to ‘pre-warm’ the soil. All the benefit comes after planting, when protection from wind, and the warmth arising from sunlight, can be used for growth. Fleece is quick to use and can lie directly on plants – my online course, Skills for Growing, teaches more about this.

Myth 13 – Feeding tomatoes

8. No need to feed tomatoes when the soil is well fed thanks to compost: these had no feeds
There is no need to feed tomatoes when the soil has been well fed thanks to compost – these plants did not have any feeds
8a. Likewise no feeds given except for feeding the soil with 6cm/2.5in compost in May before planting
Likewise no feeds given for these plants, except for feeding the soil with 6 cm (2.5 in) of compost in May, before planting

It is assumed that tomatoes need regular feeding, and yes, they do when grown in containers. Tomatoes in no dig and mulched soil often don’t need extra food, so you save time and money by not feeding them.

If plant leaves look pale, and growth is weak, then this suggests you give a liquid feed; however, this should not happen when soil has a mulch of 5–7 cm (2–3 in) of compost applied before planting. This once-a-year dressing of soil food also serves for cropping different vegetables in winter, without any further amendments during a whole year. You save time and money.

Myth 14 – Compost holds nutrients

9. I am spreading compost in December, after clearing celeriac
December – spreading the annual dose of compost, after having cleared celeriac
9a. It’s fine to spread compost in autumn and winter, because its nutrients are not soluble in water so they stay there in rain
It’s fine to spread compost in autumn and winter, because its nutrients are not soluble in water so remain there when it rains
9b. Good compost is often more brown than black, suggesting an aerated heap: new compost is on left
Good compost is often more brown than black, suggesting an aerated heap – the new compost is nearest to the camera

Plenty of gardeners believe that rain washes nutrients out of composts, so you read statements like ‘compost should be spread in spring before planting’, or ‘covered with polythene through winter if spread then’. If this were the case, planet Earth would be way less abundant than it is now, as all the food – held in humus/compost on forest floors and in grassy fields – would be washed out!

Furthermore my gardens would not have worked, because I apply compost as food for soil organisms before the winter. This means beds are ready for planting early in spring, and plant roots love the soft, weathered compost surface. A lot of rain washes through before plants start to grow.

Not covering beds with plastic is a job saved, and money too. The only time you may need a polythene cover is to kill rampant weeds in year one (See Lesson 1). In any mild winter there can be weeds germinating from newly spread compost, and a little hand weeding is worthwhile. The weed roots are easy to pull from such a soft surface – so different to the stickiness of soil.

It is important to consider biology as well as chemistry. The no dig method results in high biological activity, which supports and retains high levels of nutrients. These are not soluble in water and therefore don’t wash out, just as they do not flood the roots of plants.

One interesting point arising from how nutrients ‘hang around’ in no dig soil, is how this appears to happen less with cultivated soils. Much of the research about nutrient leaching is done on ploughed and tilled soil, yet without specifying this. A stormwater test carried out at Singing Frogs market garden in California, found clean water after it had passed through the soil. They are no dig, and apply 5 cm (2 in) of compost per year.

The owner, Paul Kaiser, argues that his circumstances are clearly within bounds, for four reasons. Firstly, he says the extra nitrogen is necessary, because he’s farming so many more crops per acre than the average farm. Secondly, he says soil tests show that his nitrogen levels are ‘right where they should be for healthy crops.’ Thirdly, he says the crops are clearly eating it up: on some, the leaves occasionally turn yellow (usually a sign of nitrogen deficiency). And fourthly, he says that his ponds, which catch the farm’s run-off, are visibly clear and full of wildlife. And recent stormwater tests were also clean, even during 2017’s heavy rains. If water is polluted with nitrogen or phosphorus, it’s normally clogged with algae, which kills fish and other aquatic life by robbing them of oxygen. This problem did plague Kaiser during the first year, after particularly heavy composting, but has pretty much ceased since then. ‘All our fields and indicators show that our nitrogen levels are OK or not enough’, Kaiser says (Craftsmanship Quarterly online magazine, Summer 2017 issue).

This quote is from the book ‘No Till Intensive Farming’, written by Bryan O’Hara, a grower of 35 years in Connecticut:

‘We have seen the phosphorus levels on the Mehlich-3 soil test drop, even though we apply 30+ tons of compost per acre per year.’ (p.188)

Myth 15 – Watering in sunlight

10. I often water in sunlight and this causes no problems whatsoever
I often water in sunlight, and this causes no problems whatsoever
10a. When compost is thoroughly watered, it holds a lot of moisture - 3 days without watering these, in sunny March weather
When compost is thoroughly watered it holds a lot of moisture – these haven’t been watered for three days, even in sunny March weather

Where does the oft-heard saying come from, that we should not water plants in bright sunlight? If it were true, all plants would suffer when the sun comes out, following rain storms in summer.

I have never observed any leaf damage from sunshine on water droplets, and, when one is not restricted by such a belief, it makes the day more flexible when there is much to do. I do hear comments from people in Texas and North Australia – that they would not water in bright sunlight – and am intrigued to know more, because tropical storms are often followed by strong sun.

Myth 16 – Deleafing celeriac

11. I am doing a trial on deleafing celeriac, and they were smaller after doing this than their full-leaf neighbours
Doing a trial on deleafing celeriac – after deleafing they ended up being smaller than their full-leaved neighbours
11a. November 2018 and all I did here was remove some rotting leaves, not before October
November 2018 – all I did here was remove some rotting leaves (but not before October)

‘You must remove the lower leaves of celeriac.’ I have a feeling that this recommendation comes from a duke or duchess, wanting their crops to look tidy and smart (though celeriac does look lovely from about August, after old leaves have twisted away from the base of swelling bulbs).

However on two occasions, when I deleafed a few plants of celeriac while leaving others untouched, the latter grew larger. The leaves worth removing are only those nearest to ground level, the yellow and rotten ones.

Further Reading

More information can be found in my book: ‘Gardening Myths and Misconceptions

sow & propagate
Transplant - Size, time of year, Spacing, support
container growing
Prune and train plants/thin fruit
Harvest times and method
Potential problems