Lamb’s lettuce (Valerianella locusta), also known as field salad or rapunzel, is a valuable autumn and winter vegetable that contains iron, folic acid and vitamin C in particular. It belongs to the valerian family (Valerianoideae) and is not related to any other vegetable species. Although the leaves have been collected as food since the Stone Age, lamb’s lettuce has only been cultivated and appreciated as a delicacy for a good hundred years. Until the 19th century lamb’s lettuce was still considered an annoying weed because it spread everywhere between winter cereals.
All garden varieties offered today are derived from the lamb’s lettuce species Valerianella locusta, which can be found growing wild, especially on lean fallow land and in vineyards. There are two different varieties: Autumn varieties with delicate, light green leaves and the compact, robust Louviers types for winter cultivation. Meanwhile, varieties for spring cultivation are also offered, but lamb’s lettuce remains a typical autumn crop.
Appearance and growth
Lamb’s lettuce is an annual, wild and hardy plant, which forms dark green, flat to upright rosettes from round to oval leaves. The leaves are about ten centimetres long. Valerianella locusta contains many vitamins and minerals and is characterized by a nutty taste.
Location and soil
Lamb’s lettuce is a rather frugal and uncomplicated vegetable. The location should only be sunny, otherwise it will grow on almost any soil. If it’s calcareous, all the better. The plants do not need many nutrients. They like to make do with what the pre-cultures have left. This characteristic and the late sowing date make lamb’s lettuce an ideal post-cultivation.
Crop rotation and mixed cultivation
Spring onions are good neighbours for lamb’s lettuce. However, cabbage vegetables have proved to be unfavourable.
A well-set vegetable bed is important for the complete germination of the lamb’s lettuce. Place the seeds in double rows five to eight centimetres apart, no more than half a centimeter to one centimeter deep, leaving 15 centimetres in between (width of a standard hoe). Cover the seed grooves with soil, press the soil with a board and keep it evenly moist. The next three weeks are decisive for success: that’s how long the seeds need to germinate and they must not dry out during this time. As evaporation protection you can cover the bed with fleece or perforated foil until the seeds run up.
You can also sow lamb’s lettuce broadly on very weedy areas. If you want to harvest in September and October, the seed is sown between mid-July and mid-August. For the harvest from November to mid-January, sow beginning to mid-September. Important: In August, the summer dryness can lead to enormous difficulties in growing up, so it is essential that you moisten the soil well before sowing, as this can easily lead to silting up. Lamb’s lettuce is usually sown too densely in the bed. If you don’t pull it out to a distance of eight to ten centimetres, the rosettes will remain small and the lower leaves will turn yellow – this makes cleaning tedious. Keep the bed weed-free and press the soil between the rows again after chopping. This makes the rosettes less dirty and easier to cut.
Lamb’s lettuce can also be preferred in greenhouses. The individual grains are best sown in multi-pot plates or Quickpot plates. When they are planted out, they are already ahead of the competing weeds in terms of growth. Fill pot plates with growing soil or a mixture of sifted compost, garden soil and sand (in equal parts). Sow three to five seeds per pot. After four weeks, the plants are planted pot by pot at intervals of eight by eight centimetres.
Keep the beds weed-free and freshly sown lamb’s lettuce moist, but not wet, otherwise there is a risk of fungal diseases. Drought, on the other hand, prevents the seed from rising and makes plants ready for harvest bloom more quickly. Wintering lamb’s lettuce needs some organic vegetable fertilizer in late winter.
Lamb’s lettuce grows quite fast. In summer sowing, the florets are cut for the first time after only eight to ten weeks. The cut requires sensitivity. Cut the plants just above the root, otherwise the rosettes will fall apart. Thanks to the higher humidity, September seeds germinate quickly – but if temperatures fall below eight degrees Celsius, growth stops. In addition, in the low-light months from November to February there is a risk that lamb’s lettuce will store nitrate in its leaves – but less in the open than in the greenhouse or under foil. Nitrate itself is not harmful, but it can turn into toxic nitrite. Since nitrate decomposes in daylight, it is better to cut the salad in the evening. Lamb’s lettuce should be eaten as fresh as possible, as the sensitive leaves wilt quickly.
If you also want to harvest in snow and frost, cover the beds in good time with winter fleece or plant a few rows of lamb’s lettuce in the cold frame. Remove the fleece on mild days and also ventilate the cold frame extensively, otherwise fungal infestation threatens! Tip: Wintering lamb’s lettuce cannot mobilize nutrients from the cold soil. To ensure that the plants continue to grow in spring, you should distribute and incorporate organic vegetable fertilizer (approx. 50 grams per square meter) between the rows from February onwards.
Louviers types such as ‘Dark Green Fullhearted’ for the winter and spring harvest are easily recognised by the oval shape of the firm, rather small leaves with the strong leaf veins. The variety grows slowly and survives longer periods of frost.
The lamb’s lettuce varieties ‘Elan’, ‘Vit’ and ‘Favor’ are hardy and mildew tolerant. The red-leaved variety ‘Ovired’ is often sold as ‘red lamb’s lettuce’ but is actually a Romana lettuce grown like lamb’s lettuce. With dense sowing and early pruning, the rosettes can be harvested and prepared like lamb’s lettuce. As the plants grow, they form loose heads. ‘Verte à coeur plein’ forms dark green rosettes with oval leaves. This hardy, frost-resistant organic variety is well suited for wintering outdoors, but should be harvested quickly in spring. Granon’ grows rapidly, is considered to be particularly bulletproof and can be sown as early as March. The batchwise cultivation of this variety enables a continuous harvest from May to the next spring.
Diseases and pests
The biggest problem – infestation with downy mildew – has now been largely solved by resistant or at least tolerant lamb’s lettuce varieties. You can also prevent this by not keeping the lamb’s lettuce bed too wet. Pests play hardly a role, also because of the late cultivation date.
Lamb’s lettuce in the our store-Shop
I am Don Burke, one of the authors at My Garden Guide. I am a horticulturist that cultivates, grows, and cares for plants, ranging from shrubs and fruits to flowers. I do it in my own garden and in my nursery. I show you how to take care of your garden and how to perform garden landscaping in an easy way, step by step.I am originally from Sydney and I wrote in local magazines. Later on, I have decided, more than two decades ago, to create my own blog. My area of specialization is related to orchid care, succulent care, and the study of the substrate and the soil. Therefore, you will see many articles dedicated to these disciplines. I also provide advice about how to improve the landscape design of your garden.