Cold comfort

My wife, kids and work colleagues all think i'm quite mad. I travelled a 300 mile round trip last night to listen to John Soulsby's talk on leeks, specifically the importance of supplementary lighting. It was well worth the effort. John is a florist by trade and has a great knowledge on the science of plants and what they need or don't need in terms of lighting/heating/feeding, learning much by trial and error, experimentation or just plain mistakes. Just like thes rest of us in fact! It was quite heavy going at times and quite technical but there is always something you can learn from these talks. Being an NVS member you can attend many such events that are going on up and down Britain pretty much every week of the year.

A pot leek specialist, John has a huge set up as he also supplies thousands of pot leek plants through a mail order business to growers the length and breadth of the country, but he has experimented with every conceivable light set up over the years to ensure he has the best possible plants when it comes to competition. As he said last night, if you can go to a talk and pick up just one tip then it's always worthwhile and I certainly had flashing lights going off in my head at some of the things he was saying. Eventually I'd like to consider growing my own leeks from pips, and I will need better conditions to 'strike' (root) them than I currently have but from what he told us last night I'm even more convinced that my current cardboard set up is more than adequate for growing on my bought in plants.



I've always been worried about sudden temperature drops causing the leeks to go to seed later in the season, and indeed I lost about half a dozen last August which I'd put down to the extreme cold we had in December and January. But last year John performed a little experiment that blows that idea right out of the water. He left a tray of tiny plants on his lawn through the depth of last Winter when we experienced temperatures in the region of minus 16deg.C. They were sometimes covered with 18" of snow. Quite incredibly, none of those plants went to seed! However, other plants that he had in his heated greenhouse he neglected from time to time in terms of depriving them of water, giving intermittent exposure to light, excess heat at times and a poor feeding regime. These plants ALL went to seed. This experiment illustrates that many plants are well adapted to coping with the cold and lets face it leeks are traditionally hardy biennials, the staple diet of the winter veg plot especially in the harsh north-east. But once you start messing about with their essentials for life then the plants become stressed and it's then that you run the risk of your plants going tits-up.



John reckons leeks are more than happy with an ambient temperature of 45degF which is a relatively lowly 7degC. My crappy little growing chamber (some cardboard boxes and silver foil!) is more than capable of maintaining this temperature but I am now of the opinion that I need to make sure I don't let the plants dry out which I may have done last season as I didn't want the roots sitting in freezing compost. Now that I know cold isn't really a major problem I won't worry too much if the night-time temperatures dip but I will ensure I keep the compost as moist at all times with water at ambient temperature. Similarly, when planted out in the beds my leeks were left to fend for themselves somewhat last season and of course we had a particularly dry summer. I shall be adopting a more regular watering regime this year and will be sinking bottomless pop bottles next to each plant to ensure water gets straight to the roots much as I do with tomatoes. I think my few plants went to seed so late in the season because of a stress check through lack of water in July rather than anything that went wrong in December or January.



I am also being very particular with switching the light on at 6pm every night and turning it off before going to work in the morning, to make sure they get the minimum 12 hours lighting. The heat from the light also helps keep the temperature well above freezing, which of course I now realise isn't a problem anyway. This will continue until March time when the day/night hours equal out and I can bring the plants into the greenhouse during the day, and the plants can benefit from the natural light spectrum.