Seed Sowing in the Greenhouses
19th Dec 2002
My main work from now through to the new year will be seed sowing, both here in my greenhouses as well as at the University greenhouses at Bangor. I suppose that at least twice a week I shall be sowing some vegetable or other to be used as part of next years Chelsea display. I shall be growing an extensive range next year of various Peppers, Chillies and Aubergines, not only for myself, but also for another display stand within the same flower pavilion.
Sir Hans Sloane
The Cadogan Estates have commissioned Elizabeth Banks Associates to produce an exhibit to commemorate the 250 years since the death of Sir Hans Sloane. Apparently he was a plant collector of some renown and the display will show the statue of Sloane with his collection and leading into his garden. The garden will be divided into two of the most important aspects of his life, The New World, based on his work in Jamaica and the Old World reflecting on plants from the Northern Hemisphere. It's pretty obvious therefore that from now on, it will certainly be full steam ahead.
Large Exhibition Onions and Shallots
First things first though, this is the traditional period for sowing your large exhibition onions as well the perfect timing for planting your exhibition shallots. 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 (F2S) 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.
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 (This is exactly the same as Levington Multi purpose) 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.
May I take this opportunity of wishing all the readers of my column a very Merry Christmas.