16th JANUARY 2003
My own re selected seed of the large Kelsae onions are doing
very well at the moment and will very shortly be ready for transplanting. We
were away from
home for two weeks over the Christmas and New Year period so the onions were
sown a week or so before we left. They were sown in Levington F2S compost
which has added sand and the germination must have been quick for them to
be ready now.
Over the years I have tried many different ways of pricking out, in the early
days I used to prick them out directly into seed trays or into small pots.
For the past few years however they have been transplanted into multi cells
40, that is 40 cells of thin disposable plastic that fits into a full sized
seed tray. These served me well as the plants very quickly established a strong
root system and in no time they were ready for potting on. Two years ago though
I tried a new system simply because space was limited under my growing lights.
They were 60 cells in a tray and I am convinced that young seedlings prefer
this smaller cell unit as the roots hit the side and bottom faster resulting
in a stronger and more upright plant. (picture attached)
They will however need potting on slightly earlier than if they were in their
40 cells. The compost that I use for the pricking out in the 60s cells is Levington
F2S, it’s fine and easily slips into the holes. Once you have loosely filled
a tray, tap it down on the bench a couple of times to make sure that there
are no empty voids in any cell. Another good tip is to bring your bag of compost
into the warm greenhouse a couple of days before you intend to use it so that
the compost and the young seedlings are all at the same temperature.
If youv’e have had a good germination and the plants are all even, the black
empty seed case of the onion should still be attached to the tip of the seedling
leaf. (picture attached) The longer you can manage to keep this attached is
a sure sign that the plants needs are adequately catered for in every way.
Too much or too little water, not enough heat, poor compost, one or all of
these things would have made the seedling die back and loose the seed case.
I have actually had a seedling leaf attached to some of my plants right up
to the final potting up stage.
Use a piece of thin cane or an old fork from the house to go right underneath
the seedlings in the tray and bring up a small cluster of them. Tease one seedling
at a time from the cluster and, always holding them gently by the leaf, insert
each one into a preformed hole in the compost. For this I have made myself
a little tool from a split cane which has been sharpened down to a point at
one end and is very useful to get the young roots inside the hole.
Over the years I have heard a lot of talk about the relevance of the length
of the young seedling root to the eventual size of your onion. In my mind that
is a load of nonsense as I have proved over the years. For convenience sake,
I actually nip off with my finger and thumb the majority of the root, leaving
just under an inch or so. This then makes it very easy to plant them and I
haven’t noticed one bit of difference in my onions. Indeed two years ago I
had, without any doubt, the best onions that I have ever grown, so there lies
the answer. Plant the seedlings so that the potential root plate will be approximately
a quarter of an inch below he surface of the compost, also select seedlings
that match each other in size and leave the weaker ones alone.
Once you have filled up a whole tray of 60 give them a good watering, I will
use water from my plastic water butt which is permanently in the greenhouse
which means that the water and plant temperature are the same. The drum was
thoroughly scrubbed clean using Armillatox during early December and then filled
with clean water with about a desert spoon full of Armillatox added to it.
This keeps the water fresh and clean as well as keeping the green algae clear
from the top of the peat based compost.
The trays are then placed in my growing cabinet with artificial lights overhead
which at this point in time will be left on for a period of 16 hours per day.
For many years I used to have them on for 24 hours, right through to mid February
and then gradually reduced down to 12. However, after noticing the quality
of the plants that I have grown at the University greenhouses at Bangor, where
the lights are always controlled at 16 hours, I decided to change with no adverse
effect at all on the plants. They will also have some bottom heat on to really
give the roots a kick start and this will be left at 70°F.
One of the main elements to good growth from now on will be the judicious use
of water, too little or too much will kill them so you have to be quite regimented
at this stage. Make sure that each and every cell within the seed tray of 60
has an adequate amount of water on a routine daily basis. I like to check mine
twice a day, first thing in the morning as well as last thing in the evening.
My best advice is, never use a large watering can, it doesn’t matter how good
the rose is it will always give too much water all at once and usually to where
you don’t want it. I always use a small 1 litre can (picture attached) with
a small orifice so that I can direct the water only to the cells that require
it. Yes it is tedious and boring but has to be done if you are to get good
onion sat the end. Indeed I would go as far as to say that the first six weeks
of growth in the young seedling onions sets your stall out for then year. If
you get nice healthy strong seedlings then you are well on your way towards
a winning set of quality large exhibition onions.
Medwyn
©Copyright Medwyn Williams