Timing Blanch Leeks for Exhibitions
12th Mar 1997
The blanch leeks have grown beyond my expectations this year, they just haven't stopped growing and during mid February they were as big as any plants that I have planted out towards the end of April in previous years.
It's not often I get concerned regarding any plant growing too well, but in this case I'm just a little bothered that they may be slightly too early. I say that because my two main shows are much later than usual this year, the Welsh Championships are on Saturday and Sunday the 30th and 31st of August whilst the National Vegetable Society Championships are not until the last weekend in September.
There"s no doubt that every plant comes to it's peak at a certain time, and leeks though they may well look fine, close inspection will often show that they have gone past their best. If they have gone over the top they may well split, and not just the one layer either, five or six flags can often split open like a carrot which renders the leek useless for exhibiting. If they don't split they will probably loose that marble like sheen which is evident when you have only to remove a single flag (leaf) when the plant is at it's optimum growing condition.
The potting mixture was certainly instrumental in getting the plants growing away at every potting stage and the addition of soil and Vermiculite to the Levington M2 and M3 at various stages of growth was in my opinion the key factor.
The proportion of soil to compost was increased at every potting stage and the soil that I used was sieved from last years onion bed around October time and kept in plastic bags underneath the greenhouse benching. The potting compost and the moistened Vermiculite was also kept warm being brought into the greenhouse three or four days before it was required.
On the 15th of February they had to be potted on from their normal final pot of 5 inch square as the roots were well and truly filling the pot. The pots used were 4 litre rose pots which are about six inches diameter but much deeper than the normal so they should have plenty of time for strong root development prior to planting them out in the polytunnel from the middle of April onwards.
Another contributory factor to their excellent growth has resulted from not collaring them too early in the manner that I have done over the years. Usually when the plants were in their five inch square pots they were given some pipe lagging material as collars and this pulled the leek as well. This year I decided not to pull up the button in this way but rather to have a cane close to the plant with a plastic support clip forming a small circle around the foliage about ten inches or more above the actual button. This means that the barrel remains green and fresh with plenty of photosynthesising being carried out. As the small clip keeps the flags together the centre of the plant is always in the dark so this very process in itself is enough to pull the button.
However when I potted them up into the 4 litre pots they had their first collar which was a thick walled ¾" bore pipe lagging 9" long and as they are very strong plants it won't be long before the button will be well out of this collar and in need of a 12" x 15" collar which is cut from black pliable plastic used by builders as damp course material.
The plants were subjected to 24 hours of artificial lighting from around the end of November right through to the middle of February at which point they were subjected to sixteen hours of lighting in an attempt to slow them down the growth rate. The bottom heat which is supplied from a Prylorn blanket covered over with three inches of damp soil was also reduced at the same time.
Even though these leeks are looking terrific I know for a fact that there are even better ones around, Bob Platt and two friends of his came over from the Midlands a few weeks ago and his friend had leeks way ahead of mine as has Steve Harris and Ivor Mace, both of which incidentally have pulled their leeks in the above fashion without using collars. Perhaps this year will be the year of the leek when we will see world records being smashed.