Genus: Lactuca sativa - Family: Asteraceae
Lettuce and its origins
Lettuce pre-dates the Ancient Greeks and Egyptians, and is believed to be a native of South-Central Asia and the Near-East. Early explorers and colonists are said to have introduced the plant to the New World. There are a large number of varieties and it is commonly used in all cuisines across the globe.
Its name derives from the Latin word “lac” meaning milk which relates to the milky secretion or juice that the plant produces
How to Plant Lettuce
Lettuce enjoys growing in a temperate climate, extremes of hot or cold will affect its growth and if the weather is too hot, the leaves will become very bitter.
In a nursery, seeds can be planted throughout the year. The seedlings should be transplanted about a month after germination. Place them in rows, about 25cm apart and with a spacing of 40cm between each row. Lettuce seeds can also be sown directly outdoors, the ideal time is between either February and April or September to October.
Plant 2g/m2 of seed and plant them in holes that are approximately 1-2cm deep.
Soil should be loose, rich in humus and well-drained. The tastiest lettuce comes from soil that has been regularly irrigated. Ideally, it should be PH neutral but can also be slightly acidic. Prepare the soil well in advance before planting. Pre-sowing, fertilise with xxxxxxxxxx xxxxxxxxxxxx (xxg/m²) and 2 weeks after transplanting seedlings add another xxg/m² of the same fertiliser. Alternatively, when foliage appears, use xx-xx g/m² of xxxxxxx xxxxxxx, immediate-release fertiliser.
When to harvest Lettuce
There is a wide and varied selection of lettuce cultivars available which increases on a yearly basis, some of the most common and important varieties are:
A. Butterhead – Has leaves that are large and fleshy. They form loose-hearted heads and have a buttery texture.
B .Iceberg – the leaves crisp, dense and crunchy in texture, they are compact in shape and light in colour with a delicate flavour.
C .Romaine – This is also known as Cos lettuce and has a characteristic elongated shape and a distinct, slightly more bitter flavour
D. Loose leaf - Loose delicate leaves that are loosely arranged on the stem, they do not form a heart. The leaves are crisp and have a light flavour.
Lettuce is harvested when it has formed a good sized head with plenty of leaves for eating. The base of the lettuce head should be cut with a sharp knife, making a clean cut, not too far down the stem as you should be able to make 2-3 cuts during the season. The average crop is 1.5kg/m2.
Did you know
A key ingredient in salads thanks to its fresh and delicate taste and being a very low calorie food, lettuce is packed with Vitamins A, C and the B group. It also has diuretic properties and can stimulate a sluggish bowel.
Not only an ingredient in salads, it can be used in a wide variety of dishes and in some cultures is even used as a cooking ingredient.
If the plants are not harvested at the correct time, the stem becomes elongated and begins to flower, growing up to a metre long; this is known as “bolting”. Lettuce for eating is always harvested before it bolts.