For most of us, making a salad begins with ‘take a lettuce’… I am old enough to remember (because as a schoolboy I worked in a greengrocer – remember those?) that the only lettuce you could buy were flabby Butterhead lettuce, each slipped into a plastic sleeve and weighing about 2 grammes. And in our geography lessons (we studied the USA) we heard about California where, apart from a land of plenty producing oranges and a wealth of edible crops that made the garden of Eden seem uninhabitable by comparison, they grew Iceberg lettuce, something virtually unknown until I ate my first Big Mac.
But home gardeners did grow a wider variety of lettuce. We grew Cos lettuce at home and ‘Webb’s Wonderful’ which, as it turned out, was as close to an Iceberg lettuce as you can get.
It is possible to grow lettuce virtually all year round but a coldframe or polytunnel are necessary to grow lettuce in winter. In theory there are several problems including fungal diseases and root aphids but these are not that common. The main issue will be rot in winter and very wet weather, sparrows attacking seedlings and slugs. Slugs will attack seedlings and, just as annoyingly, will delve deep into the heart of lettuce, making salad preparation an unpleasant experience. I am not that squeamish but I admit that I am put off my lunch if I have to forensically examine every leaf. So I do use slug pellets around my lettuce, especially at planting time, taking care to use them as though they were expensive, putting down just a few, around the plants. Never make piles of them and don’t scatter them over the plants where they will get lodged among the leaves and go mouldy.
There are many kinds of lettuce. The flabby butterheads have soft leaves and form spongy hearts, usually nicely blanched and creamy yellow colour. These are the lettuce that stick to your teeth and gums. I prefer crunchy lettuce so tend to grow crisphead lettuce which make blonde, crunchy heads or I grow Cos or Romaine lettuce. These are more upright in habit. ‘Claremont’ is one that I usually grow. Then there are oakleaf or ‘Salad Bowl’ non-heading lettuce which to not make heads. You can pick the leaves from these as you need and leave the plants to continue to grow. Similar are the ‘Lollo Rossa’ types with frilly leaves and Batavian lettuce which have frilly, rather tough leaves. I will just mention celtuce which is grown for its stems rather than the leaves and is not, despite when you may read, a cross between celery and lettuce.
Lettuce is a cool-growing crop. It does not like hot summer weather and is easier to grow in cool weather – but not cold. In fact the seeds will not germinate well if they are sown above 20c and it is sometimes suggested that the seed pack should be put in the fridge a few days before sowing. I have never done this. But you certainly don’t need high temperatures. You can sow the seeds in the garden, where they are to grow but, if growing for mature plants and not as salad leaves to be harvested as baby leaves, I prefer to sow in trays, transplanting the seedlings or in cells – as I have done this week. Sow two or three seeds per cell and thin to one seedling if they all germinate. Harden off the seedlings before planting out. Lettuce will withstand light frost so can be planted out from April onwards. Small lettuce can be planted 30cm apart with big lettuce such as ‘Webb’s Wonderful’ 40cm apart. Remember that lettuce can be eaten at every stage so you can plant 15cm apart and harvest every other one in the row when small to allow the rest to mature. This way you don’t have to wait as long for a feed and you get more from the space.
If you are new to lettuce I would suggest that a mixture is a good way to start. Most lettuce varieties will mature at the same time and it is too easy to have a dozen lettuce all ready at once. If you sow a mixture you not only get variety but they will mature over an extended period. The top photo is of a mix supplied by Real Seeds – a great company which I can’t use any more because of Brexit- GRRRR. This was a wonderful mixture with really interesting lettuce – recommended if you are in the UK – except for NI. David Cameron has a lot to answer for.
On the other hand, I would also recommend ‘Little Gem’ or one of its more recent incarnations. These are small so you can pack them into raised beds and pots and there is little waste. They also stand well, remaining in good condition for several weeks. In hot weather lettuce get tough and bitter and will run to seed. ‘Intred’ is similar but has red-flushed foliage which is attractive and, presumably, more nutritious.
You can grow lettuce very well in raised beds and pots, even window boxes, in multipurpose compost. If you want salad leaves just sow the seeds, from March to August, on the surface and you can enjoy baby leaves after about six weeks. Mature lettuce take longer to grow.
Lettuce need a neutral or alkaline soil and in acid soil the leaf tips can go brown due to calcium deficiency. A lack of water will cause similar damage.