6th Aug 1997
Earlier on this year I was desperately worried about my blanch leeks growing too well, my main concern being that they would be ready far too early and would have burnt themselves out. The good news however is that they have kept on growing really well and I shall certainly have some to exhibit towards the end of the month and hopefully at the end of September as well.
They are now on 21" long collars which they have had since the end of June, and the foliage looks terrific, I have to say that the dull weather we experienced throughout June certainly helped towards having a more even growth rate as well as preventing the foliage from being burnt. This is a general problem with the Welsh leek as the thick foliage seems to part in two with the rippling and bubbling of the upper layer making the thin epidermis or cuticle very vulnerable to the direct rays of the sun.
Preventing Foliage Burn
The only way to prevent it happening during a really hot spell is throw a thin green netting over the tunnel to act as a barrier. Be careful though when doing this that the shading is not too dense, the idea is to prevent the direct rays of the sun burning through the epidermis whilst at the same time allowing sufficient light to penetrate so that the growth rate is not impaired. Fixing up a powerful fan can also be a help so that the hot air burning down on top of the foliage is constantly re circulated.
Removing Split Flags
At the time that the 18" collars were being swapped for the 21" ones, the leeks were nearly 14" to the button and over 8½" around, however I knew when I touched them that I had a few split flags to contend with. Every year I get this problem and I'm more convinced than ever that the leek needs to do this in order to abort some of the older and narrower flags. With most of the leeks I had to remove four or even five flags and I can remember a time some years ago when I would have been at my wits end if this had happened. After removing the flags the leeks finished off at 7½" around and are now putting on the extra weight that's needed to balance the eventual length of around 21" to the button.
As this has happened much earlier on than in previous years they ought to be fine by the end of the month, however it can be a disaster if it happens a week or so before the show as you would then have to show leeks with ribbing as well as a bare area around the root plate with no roots visible where the flags have been removed. What happens after removing these flags is that new roots develop around this bare area and the leek will then grow on even stronger.
This flag splitting may have something to do with too much nutrients in the soil, although I doubt it, this year my soil analysis showed that I needed very little nutrients and in fact, because the leeks were so big at around planting time, the soil had nothing at all added to it and I'm more convinced than ever that we all have a tendency to add too much fertilisers to our already highly fertile beds.
One job that I have to do is to number every leek, this will done with a black indelible pen on to the white polythene and these numbers will be placed in a book. The next time I remove the collars, each leek will have it's length to the button measured as well as its girth half way between the root plate and the button and recorded in the book. This is useful information to record growth rate, and near to the show time is invaluable when you want to select leeks for the show bench, you will know exactly which ones will match up with each other.
Carrying out the above has a very useful cultural plus, the action of gently removing soil from around the base of the leek in order to remove split stalks cleanly away, at the same time permitting access to measure the leek from the base; loosens the soil around the leek and any stones found are naturally be removed. Before you replace the collars, scatter some slug pellets around each leek, if there are any slugs around they will most certainly love the moist atmosphere under the black and white polythene.
It is very easy at this time of year to forget about your stock leeks, they will certainly need attention, every seed head should have been tied up to a cane and each cane in turn fixed to a taut wire so that there will be minimal risk of wind damage. Give each pot a standard liquid feed at every watering and I find Phostrogen or Chempak 3 to be prefect towards maintaining a balanced growth. Any dead or dying flags can also be removed at this time and the whole plant given a spray with Dithane.