Large Exhibition Onions and Shallots
21st Dec 2000
This is the traditional period for sowing your large exhibition onions as well the perfect timing for planting your exhibition shallots.
Large Exhibition Onions
Christmas day, just before lunch I will make my way to the greenhouse with my seed in one hand and a glass of malt whiskey in the other, just to make sure that they get away to a good start. I have over the years varied from this date, I have sown them earlier as well as later only to find that I still prefer to sow them on or around the Christmas period.
Do remember when sowing the seed that at this time of year it is necessary to have some heat to help the seed germinate. This heat can be in the form of a propagator or the greenhouse may well be heated itself. A propagator with a thermostat is the best and fresh onion seed will usually germinate in under two weeks.
Use the best quality seed compost, I prefer to use the Professional range of Levington composts starting with some F2 with added sand and then progressing to a stronger mix as the seedlings develop. Always remember that even it you have the best ever propagator there will come a time very soon, when the young seedling will need to be potted on and therefore you must have some form of heating in the greenhouse as well.
Use a small clean seed tray to grow them in and sow the seed sparingly on top of the compost making sure that every seed has it's own space, this will result in a stronger and more even seedling development. Cover the seed over with the same fine compost or use some fine vermiculite which I have used for the past few years with great results. Water the compost over with a fine spray and place the tray in the propagator, I never cover the seed tray with glass or anything else but I check the surface of the compost daily and give a fine spray of water should it appear to be drying out.
Good viable seed grown in nice warm conditions should germinate within a week, but I do stress that the temperatures have to be between 65 and 70 degrees Fahrenheit.
They will be ready for transplanting to small pot or trays when they are at a stage we call 'the crook stage". This is when the seedling is about an inch and half tall with the top half of the seedling just out of the compost with the black empty seed case still attached. At this point there will only be one long seedling root and that root can often be longer in length than the actual top growth. I personally don't try to transplant the whole of those root, indeed over the past few years I have regularly pinched out the roots to an inch or so in length and this greatly helps me to transplant them much faster.
This initial root is only the seedling root and the other secondary and proper roots will develop within a matter of days, naturally you want to retain as many of these undamaged as possible right through every potting stage up to when they are planted out in their beds.
The mixture that I shall use for the initial potting will be as follows:- 3 parts of Levington M2, 1 part soil that I have already sieved from my onion bed and stored in bags in my potting shed, and 1 part Vermiculite. I was informed by a representative of Levingtons that should any of you have problems getting hold of the M2 compost, it"s exactly the same product that's in the amateur Levington Multi Purpose bag.
The 21st of December is the traditional time for planting out your shallot bulbs with a view of harvesting them on the longest day, the 21st of June. Naturally weather conditions are rarely suitable for direct planting in the soil at this time so I pot up my shallots in 3inch pots using some Levington M2 or you can make up your own mixture using Chempak potting base. They will initially, for the first two weeks, be kept in my warm greenhouse to form roots prior to being placed in my cold frame. Later on they will be potted up again to 5 inch pots from which they will be planted out in their beds.
A number of growers at my last Vegetable Growers weekend seminar asked the question 'what causes shallots to go double' or pregnant as we often call them. This will often happen after the shallots have been harvested and when they were perfectly round in the bed. I am convinced that it is certainly something to do with the length of time the shallot has been growing in the ground and that the final mis shape is merely showing that secondary growth has already taken place. It's very important to keep your eye on growth from early June onwards to make sure that the shallots are still producing young shoots from the centre. The minute this stops is the time to harvest your bulbs as they will start secondary growth after the initial growth has been exhausted.
The other method mentioned was to cut off the tops and the roots as soon as the bulbs were lifted, this stopping the sap of the foliage from going back down into the bulb, this again causing the bulbs to be mis shapen. Sadly to everyone of those points someone in the audience that weekend had tried it and the bulbs had still gone out of shape, so really I am no wiser why this happens. If any of our readers have an idea as to why it happens, in particualr some of you who have been really successful at growing them, please let me know via the editor of GN.
May I take this opportunity of wishing all the readers of my column a very Merry Christmas.