Blanched Leeks from Bulbils, Pips or Grass
19th Nov 1997
The wonderful long blanched leeks that you see adorning the backboards of vegetable displays at all the Summer flower shows are the one vegetable that are very rarely grown from seed. If you are to have any chance at all of growing such super specimens then you must have them as rooted young plants that have been started off as bulbils, pips or grass. These are names that have been given to the young growth that shoots up from the head of a leek that was re planted the previous season. Generally the pot leek tends to throw grass and is the name more associated with that variety with the blanch leek generally giving you pips or bulbils.
As these are taken off the head they are in every way similar to a cutting taken from any plant and as such will retain all the characteristics that the stock leek had. It is therefore important that when ordering leeks that you purchase them from a reputable source which will have selected only the best leeks for propagation.
If you want to try propagating these bulbils yourself then the way to do it quite simple. After you have returned home form a flower show with your leeks, these are then re planted into clean fresh compost in a nine inch pot or three or four of them in a twelve inch pot.
You only need to plant the bottom six inches or so of the actual leek after first removing the current years roots which serve no useful purpose again. Remove some of the outer flags as well until the diameter of the stem or barrel is about the same size as the root plate. Where the flags have been removed from around the root plate will be the area where new roots will develop and eventually will be the power house which will first send out new flags and the following year, a seed head.
Once the seed head emerges it is important from that point on to support the developing stalk and seed head which can grow to about four feet in height. The flower head will open up to produce seed but as we only need the plant to produce bulbils these flowers are completely removed before they even open up. If however you want to develop your own strain then you can leave a tuft of flowers at the top of the seed head which will then produce some seed. these will very often be similar to the parent but equally you will have some reversions to other strains within the plants makes up as well as some potentially new varieties. This is actually the way that Ivor Mace first developed the Welsh seedling leek.
Once you have removed the flowers the plant will very quickly throw up some green shoots and if you are lucky they will stay green and fresh on the head until you require them for pricking out at about this time of year. The stock leeks will grow for the majority of the time outside but they should be brought under cover form September onwards as too much rain getting into the centre of the head as the bulbils reach maturity can cause problems.
Pricking out the Bulbils
When you are ready to start pricking out the bulbils, make sure that everything you use is fresh and clean, wash out any seed trays in a weak dilution of Armillatox as well as soaking the propagating bench with the same dilution. After you have removed the first few bulbils from the head have a close look at the young root plate even to the extent of using a magnifying glass. The base or root plate should be perfectly clean and showing no brown marks or corkiness which means that the bulbils are starting to rot off. The best plants are most definitely produced from bulbils that are free form any disease with the base being pearly white. Even at this young stage you can have rust postules evident on the young flags and being grown on in a warm humid environment, the rust can quickly spread through the whole batch.
They can then be spaced out into the compost, I use Levington F2 with some added concreting sand for the initial rooting after which they will be potted on into Levington M2 and eventually into a soil and Levington M3 mixture. I shall give you this mixture, which is exactly the same as the one I use for my exhibition onions, at a later date.
The plants at this stage in their life must have heat to grow away and the air temperature must be kept at a minimum of 55°F. A heating cable or a proper heating blanket underneath them is certainly worth investing in as they love having their roots warm and growth is undoubtedly faster and stronger. Personally I shall also be giving them some artificial lights by means of my Philips SON T AGGRO lamp, they will have the lights on for twenty four hours a day, right through to planting out time.