My analyst sounded agitated. Not my psychoanalyst I should
add - but my soil analyst. Was I planning, he asked, to switch
from years of growing dahlias to something completely different?
Like heather?
His question, over the phone, puzzled me at first. Then came his
news.
Soil samples from each of my five beds registered pH readings
running from a low 4.8 to an even lower 4.4 figure. That is the
sort of acid water conditions which make brown trout go belly
up.
It was a bit of a shock. Samples had been sent off, a few weeks
before planting out, simply to seek guidance on nutrient levels.
My previous tests, carried out by another source, suggested that
my pH was satisfactory, a mere shade below neutral. OK - that
had been six years before. It was still hard to believe that the
level could have slumped so dramatically in so short a time.
With hindsight, I realised the warning signs had always been there.
I had been too slow to clock them. Indeed, a number of factors
pointed to the possibility of the previous tests having produced
false or “rogue” readings.
That, of course, was little consolation now. I had big problems,
confirmed the expert. Much too close to the growing season to
start adding lime. Corrective action would have to wait until
the autumn. He promised, meanwhile, to forward a list of recommended
additions to correct minor nutrient deficiencies.
He stressed, with such low pH, my prospects were not good.
Plants would face difficulty in taking up nutrients and trace
elements. I went through the routine of getting the beds top dressed,
ready for planting out.
Worse was to follow. A few nights later, returning from work,
a mini mountain of dung lay piled at my front gate. Don‘t
ask me his real name, but “Plough”, the lad who comprises
the entire workforce on a local farm, had been and gone. “I
was cleaning out the midden”, he informed my wife. “Down
at the bottom was all this black stuff. I knew that Bill would
like it...”
The only consolation, viewing the heap, was no smell and no steam.
It was dark before the shovelling finished and the last of it
was bagged and dragged up the side of the house. I counted with
a torch. There were 34 bags.
That next weekend was the start of June. I was preparing to
plant out. My wife mentioned casually that she did not expect
to have bags of dung lying about all summer. I had anticipated
such an inconsiderate attitude. This whole 1997 season, I decided,
was fast becoming one of life‘s little jokes.
There followed an act of sheer bravado. I tipped all the bags
into the beds. The heavy black cake spread about nine inches deep.
Methodically, I then scraped away a space and dug a hole for each
plant. Trying in the process to keep any lower leaves clear of
my “mulch”.
Since I only have space for about 55 plants, it worked out
at about two bags of muck for every three plants. Combining acid
soil with loads of muck, of course, is a rather dangerous formula.
Scarcely text book growing.
By this stage, I was embarked on what promised to be a rather
interesting experiment. I turned my back on the potential timebomb
ticking away in the back garden - and disappeared on a cruise
during the second half of June. When I got back, I was a bit surprised.
The plants were growing quite happily.
My cavalier conduct certainly ensured that the season would prove different. Nettles kept springing up, but scarcely a weed. The imported army of slugs were completely eliminated by the resident pair of blackbirds, which daily tossed dung over the paths. There was no disease, a marked absence of aphids, and not one single earwig.
Watering, during the early season heatwave, was a matter of
guesswork since the soil was invisible, down there somewhere.
The sprinkler made little impression on the protective layer.
In fact, it was well into October before the muck showed real
signs of breaking down. Most of us, I suspect, are influenced
in our management programme by our notes (or our memory) of how
the plants behaved the previous summer. Deploying each season,
in the case of familiar varieties, an ongoing process of “fine
tuning”. I sensed that my cocktail of low pH and high muck
took me into the unknown. Certainly, there was no question of
adding “feed” - only regular doses of potash in a bid
to cancel out the nitrogen factor.
The outcome?
Not as bad as forecast or feared. There was a certain overall
“roughness” about the blooms; top class colour quality
was again lacking; and, interestingly, each variety reacted quite
differently to the unusual environment.
Deborah`s Kiwi loved the conditions, and kept pushing the ring.
Andrew Magson’s form floated about wildly and the later blooms
went oversize.
Karenglen revealed an early mass of spindly stems and a marked
reluctance to start flowering. Sunlight Pastelle threw super early
blooms, then disappeared through the covers. Claire Diane was
brilliant, pity about those rubbery stems.
The chaos grew worse during the latter half of the show season. There was rain and poorer light and the nitrogen excess began to dominate. However, not one of my five varieties was a total disaster. All produced decent vases at some stage or other. My total output was 42 vases over 12 shows. In fact, I managed (by my modest standards) to enjoy one of my better showing seasons.
Knowledge can be gleaned from even a reckless experiment like
this one. A couple of conclusions perhaps can be passed on, for
consideration.
FORGET about toytown test tubes and even those hand held
soil “meters”. I fear that the results from do-it-yourself
“kits” are so vague that they tend to confirm whatever
type of reading is being sought. There seems no real alternative
to providing soil samples and getting your pH checked by a trusted
expert. At intervals, I would suggest, of something less than
my own six years!
FORGET about following all the scientific stuff too literally.
Dahlias don‘t read the text books and, from this experience,
don‘t necessarily require that ideal “near neutral”
pH level. Or, for that matter, any sort of standardised feeding
programmes. What each in-dividual variety clearly relishes is
its own particular regimen. Something, I suspect, that the top
showmen hit on a long time ago.
Indeed, it would appear that dahlias can tolerate a fair bit of
leeway. The pH and nutrient levels would appear to be much more
crucial for those of our members who concentrate on chrysanth
cultivation. Perhaps, some experienced chrysanth grower could
provide personal evidence to support or dispute this.
Certainly, my self inflicted damage reminded me, rather forcibly,
that while it is easy to add fertilisers - it‘s rather difficult
to remove the stuff.
My troubles, of course, are not over. I am spending the winter
months working steadily through a half-hundredweight bag of lime.
The analyst warns that next season, following the first phase
of his prescribed corrective action, the pH will move up - and
so will the overall fertility factor. Which more than likely will
present new problems with the dreaded rings.