Now I think we’ve established the reason for this article, it is how to obtaining perfect pot tubers, for that is the only way to travel if you’re a dahlia on a mission. Jack Gott assured me there was nothing to this pot tuber making, but I can assure you he’s being modest, but then he is also a man of the soil, so he wouldn't know when he was being clever, because it comes to him automatically. Let me tell you what happened when I took some late cuttings of Charlie Dimmock last year, you see I was afraid I wouldn’t have enough stock the following year, as I’d given Stan Hall as many cuttings as I could muster. Well the man was helping me make money for the charity Break Through Breast Cancer. Although the Charlie Dimmock pot tubers were perfect replicas of their large brothers, or is it sisters, in the following year only one of those pot tubers made any growth, all made roots, but they didn’t produce any shoots, in other words they were blind, lesson learnt. So to take cuttings for pot tubers later than the end of April, I think is a waste of time, now we’ll see the emails flood in, I wish I never said it really. Jack has since informed me he has been successful up to the second week in May.
I’ll tell
you about another incident that happened last year at around the same time, I
thought instead of buying in half a dozen cuttings of each new variety I wanted,
I’d change tack, and propagate from bought in pot tubers. Okay perhaps I didn’t
do to bad, I got all the cuttings I wanted off all but two varieties of the new
stock, but these two just wouldn’t send out new growth. They had all been
treated the same, on arrival I potted them up in half pots with the crown on the
surface, and I’d kept them dry until I wanted to start them up. In desperation
after reading a article by Roger Turrell I think, about stock that wouldn’t
start, I re-potted them both in to a larger pot, making sure the crown this time
was covered, they’d made plenty of root, but still know joy. I didn’t tell the
suppliers, I didn’t want to embarrass them, but if any supplier who produces
their own pot tubers, takes the trouble to look at this article, perhaps there
is a link with late struck cuttings, and blind pot tubers. If any one has
anything else to add at this juncture email me with your thoughts, I’ll print it
in
`Just Dahlias'.
Okay after all that, here’s how I propose
to grow the pot tubers I need for 2006. My very first cuttings will all be pot
tubers, that’s until I’ve obtained enough of each required variety. They’ll be
rooted as usually in multi celled seed box liners, that are filled with a 75/25
mix of multi- purpose compost and sharp sand, and placed above my heating
cables. Most will root in about two to three weeks with the thermostat set at
20C. After which they will be placed in a cooler part of the greenhouse, and
although there doesn’t appear to be anything going on, they will be filling the
small area they were rooted in with roots. I suppose using our first cuttings
for pot tubers, is the one area that we’re luckier than our Northern neighbours,
we don’t have to insert the cuttings that we want to grow our flowers with,
until late April early May, I should imagine this would be far to late a date
for the North of England and Scotland growers.
After the fourth or five week from taking the cuttings, they are potted in to a
three and a half inch square pots; fifteen will fit in an average size seed
tray, let them have as much light as possible, although after potting for a few
days they can be shaded with a piece of fleece. After a couple of weeks
they can be placed in the cold frame, ventilating on favourable days, closing
down at night. This is where I used to say cover the cold frame with suitable
material if frost should be eminent, I haven’t covered a cold frame for ten
years, although there was one year I thought I’d come unstuck. Take for
instances today, I thought I’d get on with a bit of digging, it was cold, dry,
but sunny, a perfect day for digging, as I dug my dahlia beds, on every spade
full of soil there were two or three worms, okay you say he’s lucky to have such
fertile soil, that’s not the point, it is not even mid February yet, and there
were worms in the top few inches of garden soil, things are changing. All I hope
the South doesn’t get any hotter or we’ll have to use shade cloth like our
Canadian, American, and Australian friends.
Now comes the all important bit, there are several ways to produce pot tubers
from this stage, but if you want to send them to anywhere but Europe or the
British Isles you must keep them in soil-less compost, and it mustn’t be
contaminated by garden soil. There probably aren’t any nasties in my garden but
I’m taking no chances and growing them in complete isolation. I’ll use matting
and trays that give them room to get enough light for them to develop in to
decent plants. They won’t grow like their counterparts in the garden, because as
soon as the first flower identifies they are the same as labelled, they will be
forever pinched back, forming a short flowerless plant, that’s soul perhaps is
to create a good, but miniature tuber, full of eyes for propagating from. I
shall pot up some in the next pot size up, for comparison, but Jack informs me
that the three and a half square pot is adequate, and if they become to
congested the tuber will split the plastic pot. The three main things to watch
out for are moisture, light, and nourishment. The first two become apparent, and
the last is a matter of choice, I’ll tell you what Jack does, when he makes up
his mix for potting his cuttings destined for pot tubers, he adds a quantity of
slow release fertilizer, sorted. All I do is use a in-line diluter, this way I
can alternate my feed, according to the weather, should it be dull and wet, I
can give extra potash, if sunny and dry, extra nitrogen. I was fortunate to
stumble on this method while surfing the Internet, do yourself a favour and go
to the Harry Lawson’s link on my home page, and order his book, it’s all in
there, and it’s fascinating, and as that auctioneer says `It’s as Cheap as
Chips’ and there’s a life time of knowledge in this pocket size breeder’s bible.
Okay where were we, oh yes, as soon as the season ends, and your pot tuber
plants have stopped growing, with hold feed and water, in other words keep them
damp, but stop feeding. As soon as the first sign of frost, trim back the growth
by half, and withhold the water completely. They will be alright where they are,
but should frost occur after the first cut back, apply the fleece. By the end of
November according to your location, take your charges inside, after cutting
back further, to within two inches of soil level. They can be stacked and dried
without fear of shrivelling, and later as you want to send them on their
journey, they can be cleaned, and packed with adequate protection from the
elements, for their adventure to the Big Apple, or even the Land of the Rising
Sun.
See you at the trials Ken.