How to grow Perpetual Lettuce
The lettuce that we use as ‘cut and come again’ is Perpetual Lettuce. The name is a bit of a misnomer as it will really only last about 3 months.
Now one of the original perpetual varieties is ‘ Cos’, and it can be harvested as a whole lettuce, or you can pick off the outside leaves as you need them and let it keep producing more.
Most of the perpetual varieties simply just do not form heads, and you can buy them as mixes of varieties such as ‘Oak Leaf’ and ‘Salad Bowl’ or in what is commonly called a ‘Mesculin mix’ which may include Rouge d’Hiver also known as Red Romaine. Even the ‘Oak Leaf’ comes in a few colours, red, green and a dusky bronze.
How to Grow
We here lots of gardeners say that the perpetual lettuce they have planted ‘bolts’ (goes to seed) to quickly. This is caused by the plant being put under stress, and deciding it wants to set seed ( a survival mechanism).
To prolong the growing season provide adequate moisture and protection from the hot afternoon sun. We grow ours in a self watering pot, and it only gets morning sun and then a little very late in the afternoon, it usually lasts around 3 months if we keep it moist.
As for fertiliser, we use a liquid seaweed fertiliser every two weeks.
Regular ‘picking’ is the key. The larger leaves can be coarse and a little bitter. So if you are not using the lettuce quickly enough, just pick the larger leaves and compost them….
Yes you can eat it after it has gone to seed, but it does tend to be bitter at this stage.
You can buy seedlings from spring to summer in most nurseries, seeds are also available for sale online.