Why won’t my ‘Iceberg’ grow?
Patience Painter, by email
Stefan says: This is a shame because ‘Iceberg’-type lettuces, such as ‘Webbs Wonderful’, are so useful and, in my experience, less prone to bolt than many other kinds. Unfortunately, you don’t say what you’re doing that proved unsuccessful, so I’ll give you a few general tips.
You can, of course, sow lettuce directly outdoors, but I’ve always preferred to transplant. I start with seed that I sow in modules of soilless compost in covered seed trays in the greenhouse in late March or early April. Lettuce seed germinates so easily without heat that when my heated bench is full with other things, I put the lettuce trays on the open slatted bench. If you don’t have a greenhouse, then a windowsill or anywhere with some protection from the cold will do. I sow two seeds to each module and gently push them just below the surface. When (as usual) they both germinate, I pull out the weaker.
Once the seedlings are large enough to handle, I pot them on into 5cm (2in) pots, grow them for about three weeks and then plant them out at 20cm (8in) spacing into a carefully prepared bed with sieved soil on the top and a general fertiliser raked in. Lettuces are robust, and you can push them really firmly in to the soil right up to the base of the leaves. I keep them watered, and that’s all there is to it.
But there may be an even easier option. Last spring, we were just into lockdown when I found I was short of ‘Webbs Wonderful’ seeds. Garden centres were closed but, by chance, a leaflet arrived from a well-known firm offering plug plants. I ordered some but with one delay after another, they took more than three weeks to arrive – by which point they looked all but dead. My wife was for putting them in the bin but again, lettuces proved themselves robust and I persuaded her to pot them into 5cm (2in) pots and check them daily. Sure enough, 90 per cent made it!