This Year's Two Types of Blanch Leeks
1st Apr 1998
I am growing two types of blanch leeks this year in the three long beds in the bottom polytunnel. Two of the beds will be taken up with the cleaned up Welsh seedling leek which is looking very vigorous indeed and ready for planting out in the beds as soon as I'm happy that the soil temperatures are warm enough. The third bed will be taken up with the Peter Clark leek which has a different type of foliage to the Welsh seedling and more resembles the older exhibition leek that most people grew before the Welsh seedling from Ivor Mace came on the scene.
I can get 15 plants in each bed so the total of 45 should be adequate to cover all my needs for this coming season.
Welsh Seedling and Rust
The cleaned up version of the Welsh seedling did give me a lot of trouble though in the beginning as it was badly infected with rust and if you can't keep on top of this disease it will cause you trouble right through the growing season. I was talking a few weeks ago to George Armstrong from Eccleston Chester about this problem and as George had some plants from me that also had some rust spots on them, he immediately commenced to spray every week with nothing more than a teaspoonful of washing up liquid in a litre sprayer. Do make sure that you add the washing up liquid to the water otherwise if you do it the other way round you'll find yourself with a greenhouse full of suds!
This cleared up the rust completely and I have since tried it and I can say that I have no rust spots at all to date. I can only assume that the reason it works so effectively is that it must leave a fine film of detergent on the leaf that works in two ways. First it will seal over any rust spots that are there already therefore preventing any spores from spreading. Secondly having covered over the leaf with this fine clear film it prevents any further spores from getting on to the leaf and re establishing itself. George believes that it also helps to keep whitefly and greenfly under control and has the added benefit of leaving the foliage clean and shiny.
I have used washing up liquid on a number of occasions in the past to act as a spreading agent which is very useful on shiny smooth foliage such as onions and leeks where it's difficult to get the moisture to stay on. Reading the active ingredients on one bottle of washing up liquid it contains three types of surfactants and all surfactants are basically there in the detergent to break up the surface tension of the liquid thus allowing it to foam and to penetrate solids.
The leeks will be planted hopefully within a week or so and as soon as the soil temperature is a minimum of 55°F, this means that I can then lay down the black and white polythene knowing that with the white side up the soil temperature will not drop below 50°F. I will also plant them deeper in to the soil than I did last year endeavouring to minimise the bulbing up that seems to occur, particularly on the Welsh seedling. Whilst I'm sure that the depth of planting isn't the main cause of the leeks bulbing up, I still feel that it might help as the lower down the plants are in the soil, the more likely the roots are to be evenly moist through the growing season.
When I grow my leeks for Chelsea, they end up growing away in 14" inch pots and the actual base of the leek is usually very close to the surface of the compost, yet I have never seen any of those leeks with any sign of a bulbous bottom. This I"m convinced is because of the fact that they are being grown in pots which means that I have to be more vigilant regarding the watering aspect, they are never at any time allowed to dry out.
I'm sure that the level of moisture in the beds and around the roots during the growing season is a major reason for the bulbing up. It may well be related to the plant being under stress at some point and therefore developing this symptom as it transpires moisture through the flags or foliage.
This year therefore I shall plant the leeks three inches deep in the beds and also keep a vigilant eye on the watering so that the beds will be kept uniformly moist throughout the Summer months. As soon as they are planted they will have a 12" collar placed around them, these collars are cut into squares from builders damp course material and the first square will be 12" x 15" with the next size up being 18" x 21". Having these squares cut in this way means that as the plants grows out of it's first collar the material can be unrolled and re placed the other way around giving you an increase in height every time of 3". This method has served me well over the years and is much preferred to the old system of using plastic land drainage pipes as it makes it a lot easier to inspect the barrel of the leek with no risk of damaging any of the flags.