Page 20 - Simply Vegetables Autumn 2021

No-dig growing
Following John Negus’s letter, I thought I would have a look to
see what research I could find
on no-dig and as he says there is
very little ‘independent’ research. Most evidence is from advocates
of no-dig and there are very few comparisons made between no-dig and dig growing. John mentions in his letter about Report No 1 by the HDRA (now Garden Organic), I can remember buying some reports from HDRA many years ago and low and behold No 1 was one of them! It was first printed in 1969 and reprinted
in 1974 and was edited by Lawrence D. Hills the Hon. Secretary of the organisation. I have set out some comments below for members information.
The report is made up of a number of letters from HDRA members and others, one member a Mr J.L.Chase did carry out some trials but most members just had no-dig gardens and did not compare no-dig to dig, although some had been no-dig for twenty years. I should add that no-dig can be used by organic and non- organic growers. Although HDRA members did trials from 1969 to 1974 very few seem to have had a control plot to compare the results, the main member who did was Mr Chase from Chertsey who carried out a 7-year experiment in his garden. This was from 1947 to 1954, each year compost
was added to both plots which were side by side, it was dug into one and left on the surface of the other.
failed completely. Mr Chase states that on our soil surface cultivation without digging for 3 years is quite satisfactory and even advantageous for some crops.
I should add that this is only one experiment on one type of soil so may not apply to all soils in all areas.
There are a number of other contributors to the report who are no-dig advocates, and they
One comment in the report was
that more hours were required for weeding the no-dig plot than the
dug (the opposite of what Charles Dowding says), but less time overall was spent on the no-dig owing to
the time spent digging the dug plot. Regarding cropping for the first three years it was difficult to
distinguish any pattern
in the results and there
was little difference
between the two plots,
though some crops did
better on one plot than
the other. Out of 9 crops
of peas grown over the
years 8 did better on the
dug plot and root crops
were always better on
the dug plot. Lettuce were better 5 times out of 6 on the no-dig plot and Sweet peas and sweet corn were better on the no-dig.
In the fourth year there was a change and in Mr Chase’s words “what could almost be called a breakdown of the undug plot occurred and this could be observed visually over the season”. “This deterioration continued to the end of the trial and the results became progressively worse”. In the last year only sweet peas were better in the no-dig plot and some crops
did not mention any deterioration to cropping but did not run any comparison trials either. A couple used compost and rotted sawdust as an overwintering mulch and then sowed or planted into this. One used quite large amounts of sawdust and claimed good crops and few weeds. Both
sawdust and straw were sometimes used on the footpaths and then added to the beds when rotted.
Another member mentions good crop yields for 7/ 8 years but then a deterioration and suggested digging every 7 years. They sold the property and the person who brought it cultivated it and had “magnificent” crops and the soil was very fertile. One no-digger who was on a heavy clay soil used to dig every three years.
All mentioned the large amounts of compost or other organic matter they applied, and many had been no-dig for 20 years and still getting good crops and claimed very few weeds grow.
In conclusion the HDRA decided to run further trials on no-dig growing and write a further report which I
do not have and not sure if it was published. But the editor Lawrence D. Hills felt no-dig was worth a try but was not convinced about the long-term success. You need to be fairly sure the organic matter used to cover the soil
is free of weed seeds otherwise you will need to hoe / hand weed at regular intervals.
You should remember that the report was written in 1974 and things have moved in a bit since then. The modern advocate of no-dig growing
is Charles Dowding who has written extensively on the topic and has an excellent website and YouTubes which are well worth a look. I visited his garden a few years ago and have to say
no-dig can
be used by organic and non-organic growers
20 Simply Vegetables