Medwyn Williams on starting off your leeks and onions
As soon as this season finishes I start off the leeks and onions for next year
My leeks are growing nicely at the moment with my oil burner now on thermostat and switching on whenever the temperature drops below 13C (55F). The heat is dispersed through a pipe and blown right around the benches very effectively.
I grow the leeks in either Plantpak 60s or 50s; that’s 60 or 50 cells that fit inside a normal size seed tray. I first line the trays with 2½cm (1in) or so of the compost. I then fill the cells with a mixture of Levington F2S and Humax multi-purpose compost. Both composts contain silver sand, with Humax also containing some sieved sterilised top soil, which the leeks seem to like. I’m growing four types of leeks and, barring any problems, they should be ready to be moved on to 9cm (3½in) plastic pots during the middle of December, with the mixture at that point being just Humax multi-purpose. This compost is undoubtedly the best I’ve ever used. It’s clean and, would you believe it, there are no pieces of wood or any other unwanted material in it.
I grew five large onions in 50 litre pots on a bench in my double-skinned polytunnel this year and I was very happy with the results I had. These onion plants were very kindly given to me by Bill Jones from Wrexham and they were from three different types of seed. I intend to sow my own large onions this week using the world record-winning seed from Peter Glazebrook. I’ll sow the seed individually and spaced out on top of Levington F1S, in a half-sized seed tray, covering with super fine Vermiculite. I’ll then plant them out into Plantpak 60s or 50s, as I do with the leeks.
If you really want to grow a big onion then you must be prepared to spend a fair bit of money on adequate heating as well as quality artificial lighting. As soon as my seeds have germinated I’ll place them under my T5 lights, which I lower down close to the seedlings to give them optimum light. If you can’t afford the expense then we do sell the Peter Glazebrook onions as premium plants in our 2018 catalogue.