Strong Onion Plants for the Large Exhibition Classes
20th Mar 2000
This year I have tried to get very strong onion plants for the large exhibition classes without pushing them along too early and too quickly. They were sown just after Christmas in an attempt to get them to mature slightly later giving me a better selection for the later shows. I am not after onions for the heavy classes, merely a good quality set at around the 22 inch in circumference mark which always have good condition on them. They are now in 5 inch square pots and from these pots they will be planted directly into their growing quarter in about two to three weeks time.
In the meantime I need to concentrate my activities on to the actual growing area which consists of three raised beds all under my 25 ft long by 12 foot wide polytunnel. The beds were completed later than usual this year as I had a three week break from the garden in October and they are now ready to receive the soil warming cables. The ones that I use are now four years old and are still working well, so it does pay to invest in these as they will last you for many years.
Soil Warming Cables
Burying the cables is not an easy task and one that can be accomplished easier if you have a friend to help you. I like to bury mine around nine inches deep bringing it back and forth along the bed within about six inches to each other. Do make sure when burying the cables that they are not touching each other and at no point should they cross each other. I push a spade into the friable soil to form a Vee and as soon as I have a few feet open my friend will then push the cable as far down as it will go into the bottom of the Vee using a flat piece of wood.
Prior to laying the cable the first job is to totally unwind it and lay it out over an adjoining bed and then switching it on for a few minutes to warm up. This is essential in order to make the cable supple and remove any kinks that may be in it. Once the cable has been laid cover it over with the soil and rake the whole bed level, you are then in a position to moisten the soil thoroughly. You must always remember that soil warming cables only work properly when the beds are moist, it's not so much the actual soil itself that they warm up, rather the moisture between each soil particle.
The next step is to apply whatever fertilisers that you intend to use and this will normally be as a result of your soil analysis report from the chemist. Very often, if your soil is in good shape, the amounts required to be added per square metre will be very small, but however small it may be, it"s vital that it's added to the top spit at the correct rate. Working it into the top spit whilst at the same time generating a nice tilth is a pleasant job with a fork, but if you can use a small tiller then the soil texture will be far superior.
I have just taken delivery of a new Honda light weight rotovator that can easily be lifted up onto the beds with one hand and this rotovator, believe me, is very powerful for such a small machine. The soil is in such good heart with years of organic matter having been incorporated into it that when it was rotovated by the Honda machine, it really was a joy to work your hands into it and the planting itself will be so easy with no hand trowel required.
The next stage is to mark out the beds ready for the onions giving them as much room as you can, if you can get 20 inches each way between the plants you are doing well, in my case I usually have to put up with 18 inches each way and the minimum in my opinion being 15 inches. Use a straight line and then measure the distance along the line and create a planting hole at each station. Once the hole has been opened, insert a pot into the hole and lightly compact the soil around it keeping to the line every time. The inserted pot will be same type as the ones the plants are growing in so that at planting time all you do is remove the pot and drop the root ball into the pre formed hole.
Next scatter a few slug pellets along the surface before covering the whole bed with black and white polythene with the white side facing upwards. The polythene can either be tucked into the soil along the outer edges or leave the surplus material drape down over the sides of the bed. Now that the pots are in position underneath the polythene, getting a straight row of onions is no problem as the slits in the polythene will be cut out from corner to corner on each pre inserted pot. Years ago I used to lay the polythene first and then cut the slits in it, it was almost impossible to keep a straight line with the polythene continuously moving about.
Once the polythene is laid, make a tiny hole in it near the centre of the bed and push through it a soil thermometer, this is a must as you will only be planting the onions when the temperature of the soil underneath the black and white polythene remains consistently at or above 50° F. How long it takes depends a great deal on the weather conditions at the time, generally I switch my cables on a week before I intend to plant the onions