Mixes for Onions
26th Jan 2005
I am quite happy at the moment with all my leeks and onions, they are certainly growing away well.
The onions are currently in their Multi cell 60s and ready to be moved this coming week into 3½ inch pots. This can be a very pleasant task, particularly if you have nice strong upright plants and care must therefore be taken in mixing up the right caliber of compost in order to get the best possible results from them.
Up to this stage the onion seedlings have been grown in Levington F2S which is a peat based medium strength compost with added fine sand. Now I shall introduce some soil into the mix in order to start preparing the plant for the sort of medium that it will eventually be growing in when planted in their beds. The mix will be 3 Parts Levington M2 and 1 part sieved top soil as well as one part of medium grade Vermiculite. There's no doubt that the plants love Vermiculite as it helps to produce some really strong white roots allowing them to breathe as plenty of air is available to them. Getting some nice quality top soil is also essential, you can sieve up some soil from your onion or leek beds, or you can but it in bags already sieved and sterilized.
Last year I had a visit to Westlands factory over in Dungannon Ireland and I was really impressed with the standard of all the products. Their peat is Irish moss and the feel of the compost range is beautiful to handle. Whilst there I was shown the quality of the soil that they use to create their own Top Soil in a bag and it really felt good to the touch. I have used this for two years now without any problems so if you do have a problem getting hold of the right caliber of soil, then try this material which is already sieved and sterilized.
Temperature and Additives
When you are mixing up the compost, make sure that you have the compost in the greenhouse for at least a day prior to using it in order for it to be at the same temperature as the plants. This will get your plants growing away immediately without any trace of a check to their growth. Adding the Vermiculite naturally has the effect of lowering the strength of the compost as it has no food or nutrient value whatsoever. I therefore like to add about a level desert spoon full of John Innes potting base to a builders bucket full of mixture. Another product that I used last year with some quite amazing results was Nutrimate, this is not a fertilizer at all rather an additive that allows the plants to glean the optimum out of whatever nutrients there already exists in either your soil or in the potting mixture. Again I will add the same quantity of Nutrimate to the mixture as I did of the potting base.
The onions coming out of the 60s cells will be well rooted so whole root ball should come away intact. Select the strongest and most even plants and those with a lovely even green colour. Should there be any with a tiny white or yellow streak visible on the leaf, discard them as they could have a virus in them. Fill the pot to the rim with the compost and make a hole to receive the small root ball with your fingers, insert the root ball and pack the compost around it making sure the neck is as upright as possible. Finally lift the pot up from the bench and tap it down once just to really settle the compost around the root ball without over compaction.
At this stage I will start to use the plastic plant support clips that are such a quick and valuable aid to keep the plants upright. Push a 12 inch tall split cane into the pot about and inch or so away from the plant and push one end of the clip onto the cane whilst turning the clip around the plant and snapping on the other end to the cane. This forms a complete circle which will help support the growing leaves. The clips will need regular attention as the young centre shoot can sometimes miss the clip and start to grow outside it which will cause the plant to be misshapen. In a few weeks time an extra clip can used further up the cane, at later potting stages the cane be an 18 inch one and as many as 6 clips can be used to form a ladder or cage around the foliage to contain the many leaves that will follow and keep the plant upright.
One task I need to do this week is to sow onions for the under 250 gram class or the old 8 ounce class which is so popular at all vegetable shows giving the ordinary gardener with the smallest of gardens a good chance to beat the big boys.
Last I grew Carlos which is a beautiful Kelsae shape, although I never managed to win with it, all dishes staged were amongst the cards at all the premier shows. Tasco is another very reliable variety that I introduced for the first time a few years ago, it has a beautiful upright growing habit and the harvested globe shaped bulbs have a rich hazel nut brown colour. The third one that I'm going to sow is Canto, this a new release in my seed catalogue this year and I do expect this one to perform well. All of those can now be purchased direct through my on line shop which has recently been up and running - go to firstname.lastname@example.org and follow the on screen directions.