General
This winter vegetable belongs to the Valerianaceae family. Its scientific name is Valerianella olitora. It is a native plant that has been used for a long time. Depending on the region, it is called boursette, sweetie, raiponce, wheat salad, hare's ear. In Switzerland it is called rampon and in England it is called lamb's lettuce. It is not uncommon to find it in the fields after the harvest, but its cultivation only dates back to the 17th century. Lamb's lettuce is rich in vitamins and is eaten in salads; alone or mixed with other vegetables such as chicory or beetroot.
It is a biennial plant that is characterized by a rosette of green leaves that vary in size and shape depending on the species. The roots are numerous and thin and occupy the first 25 cm of the ground. In the second year, after the winter, the plant develops its flower spike and when it is fully grown, the flowers give off an unpleasant odor; self-fertilization is the rule. The rounded seeds are gray pods. Their size depends on the variety. There are small and larger ones (600 to 1000 per gram). The shelf life varies between 5 and 10 years. The average germination period is 8 days, depending on the climate.
Classification
Varieties of lamb's lettuce are divided into two main groups:
- Large-seed lamb's lettuceIt groups the high-yielding and long-leaved varieties (hare's ear). The taste of these varieties does not match that of small-leaved lamb's lettuce. In this group we find Dutch large-seed lamb's lettuce, green with a full heart, royal round variety, valgros, etc.
- Finely sown lamb's lettuceThese varieties have a lower yield but are more resistant to the winter cold. Their leaves are smaller and greener. The delicacy of their taste is reserved for true gourmets. Varieties include: Etampes green lamb's lettuce, Cambrai green, etc.
Requirements
Lamb's lettuce can be grown under all Chinese trees and is very resistant to cold, so it is ideal for growing in a garden greenhouse. On the other hand, lamb's lettuce fears heat, and therefore it should not be sown too early in the summer. Lamb's lettuce does not make any special demands on the soil. The most favorable will be fresh, of good physical consistency, free of weeds and also have good firmness. Lamb's lettuce is an undemanding plant that is always grown after other crops from which it benefits from the fertilization. It is a typical example of a catch crop after a potato harvest, for example. In some cases, nitrate nitrogen applications can be considered (2 kg of ammonium nitrate per hectare).
In general, soil cultivation is limited to digging and raking. In all cases, the soil must be free of weeds. This is achieved mechanically or chemically using a herbicide (e.g. a product based on a monoid).
Culture
To facilitate cultivation (hoeing and weeding), we recommend light sowing in rows 20 cm apart (hoe width). The seeds are buried with a light rake, after which the soil is ploughed seriously. Good watering is often necessary at this stage of the crop.
Sowing in early August already makes a harvest possible in October. The plants are spread out until mid-September to harvest in winter and spring. After March, any cultivation is made impossible by the plants that are going to sow. Cultivation of the crop is limited to hoeing and weeding; everything is done to protect the plants from weeds and drought.
Harvest
Harvest as soon as the rosettes are honestly formed. They are cut with a knife to the ground and the leaves outside the base are removed, which are often yellow or damaged. In case of heavy frost, it is advisable to protect the crop with frames and mats. This protection also makes it possible to harvest cleaner and less humid products. Up to 1 kg of leaves can be harvested per m². Lamb's lettuce is very resistant to pests. However, rust and mildew attack the plant in autumn and winter. They occur in soils that are too wet or in poorly diluted crops.