Growing Small Onions from Seed
29th Apr 1998
Not so many years ago, the class for small onions or onions under 8 ounces as they used to be called, would be staged predominantly by onions from sets, not any more though. The plant breeders have carried out some marvellous breeding work in the onions, giving us very high quality bulbs from seed together with the consistency and vigour that comes with the F1 hybrids. However there are still some excellent onions that can be grown from sets, but for uniformity of shape and colour I mainly grow mine now from seed.
My seed were sown on the 14th of January in one of my heated greenhouses, the temperature is kept at a minimum of 55°F but are given no artificial lights to boost them along.
The onion that has undoubtedly made it's mark over the past couple of years has been the variety called Toughball, it seems to have all the requirements that the judges handbook is looking for. It harvests right down to a very thin neck, good shape and possesses an excellent deep brown colour which is sure to catch the judges eye.
Another good onion that was trialled for me last year by Ron Macfarlane from Pembroke was Bison, it has the shape and form of Toughball and if anything matures earlier, Ron is also growing another new variety for me this year and if the breeders report is anything to go by, it could be another onion that will be competing for the red cards.
As soon as the onions were through the compost and at the crook stage, that is when the tip of the onion leaf is through the compost (usually with the empty seed case still attached) and just before it is upright. They were then potted on individually into Multi cell trays using Levington M2, I have a tray of these that has 84 cells in it with each one measuring just over 25mm square.
As soon as they were showing 3 proper leaves they were further potted up into 3" square pots again using M2 with a small amount of vermiculite added. Towards the end of March they were potted on again into 5" pots this time introducing soil into the mix and the ratio was as follows 3 parts M3, 2 parts sieved soil from my leek bed and 1 part vermiculite. At this point every plant is given support through using split canes and plastic plant support clips. Spraying is very important from this stage on as my onions will be grown throughout in the greenhouse on the staging that forms my growing cabinet during the Winter months so pests and disease can easily get out of control.
Thrips are the biggest problem manifesting themselves as a silvery colour on the foliage which means that they have been regularly taking bites out your foliage, many growers when they see this silvery sheen on the leaves believe they have mildew or some other disease and commence to spray with a fungicide. If you very carefully open out the foliage form the centre, exposing the heart of the plant, you can just about see these pests with your naked eye crawling around all over the young foliage.
I have found that spraying on a regular basis, every 10 days alternating with Polysect and Malathion helps to keep these under control and prevents the pest from destroying your ultimate goal. The plants will finally be potted up into 7" pots and the mix for these will be as follows 4 parts M3 4parts sieved soil from the leek bed and one part vermiculite. added to this will be 2 ounces of Chempak BTD per Bushel to maintain a steady growth as well as maintaining a high nutrient level that the vermiculite will undoubtedly have lowered.
In my opinion there is no doubt that the incorporation of vermiculite into the compost gives improved root development as it creates a free draining compost resulting in added air getting at the root system. Since I have been using this mixture with my leeks and exhibition onions, the difference in the root development is quite remarkable. The plants will now be kept on the bench throughout and as the bulbs develop they will be regularly measured to make sure that they comply with the requirements of the respective schedules. I shall deal with this point nearer to the show date.
As I pointed out a few weeks ago it is vital that you now study every show schedule carefully to ascertain under which rules the classes are going to be judged. The new National Vegetable Society Handbook, which is being used for the first time this year, is completely different from the RHS one; particularly so with these onions and to the extent that you could find yourself being awarded the dreaded N.A.S. card (not according to schedule) The weight of these onions must not exceed 250 grammes if judged under NVS rules and under 227grammes if judged under RHS rules. In reality, and in order to ensure that you have onions entered as close as possible to the optimiu weight under duffering schedule rules, you will have to grow two lots.
The points, although both have a maximum of 15, are also broken down differently and are as follows : RHS - Condition 5, Size 3, Shape and Colour 3, Uniformity 4. NVS - Condition 5, Uniformity 3, Shape 3, Size 2, Colour 2. You therefore have more points under NVS rules for Size Shape and Colour than you have for Uniformity.
Please read your schedules carefully this year, you have been informed in plenty of time.