Christmas - Sowing your Onions
25th Dec 1996
could be more pleasurable on a Christmas morning than taking a stroll to your warm greenhouse with a tot of whiskey to sow your onions with each sip making the onions that Mel Ednie grows mere pickling shallots! Oh well we can all dream but the reality is that if you start now using the correct strain of seed and the correct procedures you could have an unbeatable set of onions to stage next August.
Heating and Lighting
One thing to remember is that when sowing this early in the season, you must have heat and ideally you also need artificial lights and adequate ventilation control. My Parwin heater has lasted me well. it's 3kw and is more than adequate to maintain the 60° F that is required for steady growth.
This year I intend to sow the seed individually in seed trays but as the seed is black and the Levington F1 compost is also dark, I will sieve some flour on top which is perfect for showing the spacing between each seed. This way each emerging seedling will be given adequate space for development without overcrowding. The seed will be covered over with fine vermiculite, this will ensure that the germination is much higher as the young plants can easily push themselves through the vermiculite rather than the seed case being trapped underneath the heavier seed compost. Water using a fine mist spray so as not to disturb the seeds and place in a propagator until germination takes place.
Once germinated they will be placed inside my growing cabinet which has bottom heat as well and maintained at around 65° F. The Philips Gro lamp with a SON T AGGRO bulb will be left on for twenty four hours each day for the first six weeks after which the lights will be left on for 14 hours. Controlling your temperature at this stage of growth is vital and any extremes will cause problems that will often not become apparent until much later on in the season. Bolting or going to seed is one obvious problem, but the onion plants going double can also be attributed to poor cultural techniques.
If the growing conditions within your greenhouse and inside the growing cabinet are idyllic, within ten to fourteen days the young seedlings will be ready for moving on into their first pot. I use Plantpak 24s for this task and the mixture will be as follows : 3 parts Levington M2 or you can use The Sinclair Horticulture Professional range which is SHL potting compost, this is the compost that Mel Ednie uses; 1 part soil passed through a ½" sieve to ensure that the texture is rough and 1 part Vermiculite which I shall moisten well before using. This mixture will be prepared a couple of days prior to actually potting them, moistened to the correct moisture content and placed back into a polythene bag and left to warm up to the growing temperatures.
It"s important to make sure that all the materials are to hand well before this date and left inside the greenhouse to warm up, the last thing the plants want is a check to their growing cycle. No water will be given at this stage as the plants should be made to work inside the pot searching out every available drop of moisture. Watering will commence a few days later using tepid water to ensure that the roots are never subjected to temperatures lower than those they are going to be growing in.
They say they always grow things bigger and better over in the United States of America, well I have just heard from Mel Ednie that a grower from Seattle, on the North West corner of the states, Earl Welch, has just grown an onion weighing in at 8lb 3ozs inside his polytunnel, the heaviest he has ever grown after being at it since 1988. Believe it or not he grew it that big because he read the article that I wrote on Mel Ednie's way of growing onions in Garden News which he gets regularly every week, the paper that seems to get to every corner of the globe! I am reliably informed that Mel has his eyes firmly fixed on the States now, just in case his World record gets shattered!
A very Merry Christmas to all readers.