Lettuce belongs to the daisy family. It is a fast-growing crop that is suitable as a pre- and post-crop and, depending on the variety, for spring or summer sowing. Lettuce is a classic among the lettuce varieties, especially the most widely used green leafy one, which is often referred to as butter lettuce.
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Lettuce varieties
In addition to the well-known green-leaved varieties, there are also lettuces with yellowish or reddish to bronze-colored leaves, whereby the reddish colors are either dependent on the variety or due to a relatively high supply of light. The consistency of the leaves of red lettuce is much finer than that of green. In addition, red lettuce is free from bitter substances, which are partly responsible for the taste of green varieties.
Lettuce consists of 95% water, but still contains various minerals and fiber as well as folic acid and vitamins, whereby heads of lettuce from the field contain significantly more of these ingredients than those grown in the greenhouse, for example. The reason for this is the much lower incidence of light in the greenhouse. Lettuce can be grown both in the greenhouse and outdoors. Lettuce, which was grown relatively early under glass, often does not have as strong a head as when grown outdoors. In addition, lettuce from the greenhouse has a significantly higher nitrate content.
Planted lettuce in mixed culture can have a positive effect on the quality and also prevent pests. Savory, dill, French or runner beans, peas, cucumbers, cabbage, strawberries, leeks, radishes, radishes, carrots, beetroot, tomatoes and onions have proven to be good neighbors. Celery and parsley are unsuitable for a mixed culture with lettuce.
sowing
When buying the seeds, one should pay attention to whether it is a variety for spring or summer cultivation. For example, if you plant a spring variety in summer it can happen that the lettuce shoots up very quickly. In addition, you should always choose varieties that are particularly resistant to various fungal diseases and pests.
Sowing can be done as early as February, but then in an appropriate cold frame or under glass. It can be sown directly outdoors from April to August. In the beginning, a cover made of fleece is advisable in rough locations. By staggered sowing about every 3-6 weeks, fresh lettuce can be harvested throughout the season.
When sowing, the seeds are placed about 1.5 cm deep in the earth and only lightly covered with earth, because lettuce is one of the light germs. The ideal germination temperature is between 12 and 16 degrees. The difference between day and night temperature should be at least 5 degrees.
Now the whole thing has to be kept evenly moist. When sowing in summer, you can also pre-germinate the seeds in damp kitchen paper for 1-2 days in the refrigerator and then sow them, because the seeds sometimes germinate poorly in summer due to the heat. If the plants are then large enough, they can be separated to a distance of 25-30 cm.
planting
- In early spring, early spring young plants are offered in specialist garden shops.
- This can be worthwhile if you want to harvest your own lettuce in May.
- You can then plant these young plants under foil or glass.
- In sunny weather it should be aired regularly.
- This prevents the young plants or the earth from becoming moldy.
- If longer lasting frosts are to be expected, the plants should also be covered.
- From April, young plants can then be planted directly in the field.
- Provided the ground is no longer frozen.
- There should be a planting distance of about 25 cm between the rows and the individual plants.
- Do not plant the plants too deep, otherwise they could rot easily.
location
The location for lettuce should be sunny, especially in spring and autumn. In a summer culture, a cooler place is more advantageous. The soil should be loose and well-drained, rich in nutrients, humus and not too acidic. The pH value should not be below 5.5. In addition, the soil should always be kept evenly moist, but not too wet. Heavy soils with a tendency to silt are unsuitable.
Watering and fertilizing
If the drought persists, you should water regularly. Otherwise the leaves would harden and the plant would shoot up. When the first heads form, watering should be reduced and care should be taken not to pour over the leaves, but only on the ground. A layer of mulch around the heads can keep weeds out and also keep moisture in the soil.
Can be fertilized with compost. If the soil has already been fertilized by previous crops, further fertilization can be dispensed with. A fertilizer with a high nitrogen content is unsuitable as it increases the nitrate content of the lettuce. It also makes the plants more susceptible to pests and diseases. Manure is also unsuitable as a fertilizer because it would, among other things, promote rot.
If you want to grow lettuce on the balcony, you should make sure that the substrate is not too rich in nutrients. There are special vegetable compost in stores for such purposes, or you mix humus-rich garden soil with sand in a ratio of 2: 1, i.e. two parts of garden soil and one part of sand.
harvest
It takes about 8 weeks from the first sowing to the first harvest. If sown early, harvesting can be carried out as early as May. Lettuce can be harvested before it is fully ripe. This is even advisable, otherwise too many heads are ready to be harvested at the same time. As a rule, it is then hardly possible to use up the possibly large number of heads of lettuce in a relatively short time, because lettuce does not last long.
Because of this, it is advisable to sow several times with a delay and, if possible, only as much as you can consume in a relatively short time. In this way, the harvest period can be extended significantly as the heads gradually ripen. Once picked, lettuce can be kept in the fridge’s vegetable drawer for around two days if you wrap it in damp kitchen paper.
Pests and diseases
There are now numerous varieties on the market that have a certain degree of resistance to certain pests and fungal diseases. In the best case, you should ideally also opt for these varieties when buying. Less or non-resistant varieties are susceptible to various pests as well as diseases such as green lettuce aphids, ground worms and snails or downy mildew.
Salad leafless
If there is an infestation, reddish, yellowish, green or black lice can be seen on the leaves. The leaves are curled up and often have mosaic-like spots. The lettuce aphid sometimes even attacks resistant lettuce varieties.
Fighting should be started as long as the lettuce has not yet formed heads, because the aphids are well protected in a closed head of lettuce. However, control is only possible on a chemical basis in the form of appropriate insecticides.
Erdraupen
First of all, feeding holes on the outer leaves of the lettuce indicate an infestation with earthworms. These are irregularly shaped. A few days later there is damage to the root necks and roots. Young plants usually die, older plants are generally stunted. This often leads to the total loss of the plants.
In order to combat the groundworms, the plants should first be checked regularly for 2 mm yellowish eggs from May to July. These are usually in the form of smaller egg clusters on the underside of the leaves. The green-brownish caterpillars hatch in a relatively short time.
These have to be read regularly and in some cases also dug up, as only the very young animals sit on the leaves for a few days. The older ones are mostly located at the root neck, about 1cm below the surface of the earth. SC nematodes (Steinernema carpocapsae), a special type of nematode that is also used to combat mole crickets, can also be used. These beneficial insects are completely harmless to humans, animals and other plants.
You can prevent these earthworms, for example, by regular loosening of the soil and balanced soil moisture. You can also sprinkle the lettuce with sage or tansy tea. A mixed culture, for example with tomatoes, can also prevent this pest.
Snails
Lettuce is also very popular with snails. These can be combated with slug pellets, for example, or the plants can be protected with a snail fence. The safest thing to do, however, is to regularly read the unsavory animals.
Wrong mildew
Downy mildew first shows itself as yellow later brown spots and a white to brownish fluff on the underside of the leaves. The main cause of downy mildew is permanently damp weather. It occurs on lettuce especially in late summer and autumn.
To combat downy mildew, it is first important to remove and dispose of the affected lettuce plants to prevent it from spreading. Furthermore, nitrogen-based fertilization should be avoided. Corresponding pesticides are available commercially. You can also spray the lettuce with homemade soups made from onions, garlic or horsetail, but only if the infestation is initially or still low.
To prevent all of this, it is advisable to only buy the seeds of powdery mildew-resistant varieties.
Resistant and tolerant lettuce
‘ Alambra ‘ – The ‘Alambra’ variety is very productive, produces large, firm heads and is characterized by a certain resistance to powdery mildew and aphids. This lettuce can be grown all season long.
‘ Dynamite ‘ – This particularly easy-to-grow butter lettuce forms medium-sized, compact heads. The lettuce variety is resistant to downy mildew, root lice and green lettuce aphids.
‘ Manouska ‘ – The ‘Manouska’ lettuce variety has the best quality and yield properties. This new breed is suitable for the entire outdoor season and is resistant to downy mildew and green lettuce aphids. These seeds are available as pill seeds, which makes sowing a lot easier and safer. So-called pill seeds are seeds that can germinate and are covered with a clay mass, which protects the seeds from predators and improves water absorption.
‘ Roxy ‘ – The ‘Roxy’ variety is also a new breed, a resistant successor to the brown defiant head. It is bump-proof, forms shiny red heads with slightly blistered leaves and is resistant to powdery mildew and insensitive to internal burns. In the case of internal burn, there is a physiological calcium deficiency in the leaf margins, which leads to brown discoloration on the same. This variety is also suitable for the entire outdoor season.
Conclusion
The cultivation of lettuce is actually unproblematic, provided you pay attention to whether it is a variety for spring or summer cultivation, avoid waterlogging and water regularly when it is dry. If you then only opt for robust and resistant varieties and re-sow the lettuce again and again with a time lag, you can harvest fresh and healthy heads of lettuce for many weeks.