Aiming for World Record Leeks
18th Jul 2002
My leeks are doing well at the moment and I probably stand a better chance than last year of getting some really good specimens. Last year the plants had been pulled or drawn upwards early on when in the pot stage so that after planting they were very quickly up to an 18 inch collar and most of them had to have a 21 inch around this time of year.
This year the young plants were allowed more space when in their pots and when hardening them off so that the button was a lot lower down when planted. This means that the plants have only just been moved from their 15 inch high collars to an 18 inch. Last year when planting out on the 1st May the leeks were already 12 inches to the button and after planting I put the 18 inch collar on them straight off.
I have said before that a good guide line if you are really after growing a world record leek is to remember the simple measurement and date that Peter Holden gave me. When Peter broke the World Record with his blanch leeks a couple of years ago they measured 6.6 inches around on the 6th of June. Very easy therefore to remember this fact, all the sixes - 6.6 on the 6th day of the 6th month. When I measured mine on the 6th they were slightly behind this but when I measured them on Sunday 23rd June the best leek was 7¼ inches around with a few there at 7 inches. Now that I am much later putting the 18 inch collar on it should be sufficient right through to the end of the season.
The one danger to leeks from now on is too much heat getting at them, if we have a few very hot days, the tunnel can become a very effective oven and the direct rays of the sun piercing through the polythene can literally burn the foliage away. The Welsh selection of leek is very prone to this as the leaf is much thicker and the flag when maturing has the effect of bubbling up as it parts in two making it more vulnerable to burning. I controlled this last year by creating a false ceiling above the leeks made from roofing battens and then lined it over with thick fleece. This allows enough light to pass through but blocks the searing heat and prevents it from damaging the foliage.
Another problem that can happen on very hot days is the heat that can take place inside the black builders damp course material that we use as collars. In order to prevent this happening I make an additional set of collars from thin polystyrene which is covered over on one side by some silvery material. This has the effect of cooling the leek barrel as the silvery colour has the effect of dispersing the heat away from the plant.
One problem I have had during the middle of June was an attack by a swarm of small pale green caterpillars which can cause havoc on your flags as they munch their way through them. I was lucky enough to spot the problem in time and proves the fact that there is nothing better than walking through your garden on a regular basis having a good look at all the plants foliage. The old saying is definitely true, a stitch in time saves nine. The problem was caused by the leek moth and though the caterpillars are only about half an inch in length, they can be very damaging. Worst of all they can affect your onions as well and tunnel inside the foliage eating their way downwards to the heart of the onion and devastating your crop. In order to control the pest you must spray with a suitable pesticide.
I also spotted at the same time a few rust spots and these were immediately covered over with some Vaseline to prevent the spores from spreading. I shall have to be very vigilant from now on if I am to keep the plants free from this disease. Supporting the leek flags or foliage is also very important, the weight on the flags of one well grown leek is tremendous and unless evenly supported can cause the barrel of the leek to bend. I use chains suspended from the roof of the polytunnel which support a thick walled plastic pipe over which the flags are draped over. The position of the support pipe from the leek is important as the flags need to be uniformly supported on both sides.
I don't anticipate having to feed the leeks at this stage as it would do more harm than good, the saying is why fix something that ain't broke, in other words if a plant is really growing well, leave it alone. If they continue to grow as well as they are now and not splitting excessively, then I may be tempted to give them a feed of Potassium Nitrate later on in the season to harden them off. I did this with my large exhibition onions last year and it certainly hardened them up. I shall probably give the leeks half an ounce of Potassium Nitrate to 1 gallon and each plant will have a pint. I will probably do this about two weeks before the Welsh Championships and another feed on my return from the championships.