With a good selection of plants, the hobby gardener can enjoy fresh lettuce from spring to autumn. But garden salads like lettuce tend to shoot under certain conditions. The plant develops an inflorescence early, which affects the harvest.
Why does lettuce shoot and how can you prevent it?
Lettuce shoots when stress factors such as short planting distances, soil that is too dry or high temperatures impair growth. To prevent this, ensure there is enough planting distance, sufficient watering and choose bolt-resistant lettuce varieties such as 'Ovation', 'Lucinde' or 'Pirat'.
Things to know about growth
Lettuces are annual plants that complete their growing season within one season. First, depending on the variety, a loose to dense rosette of leaves forms, which forms the head of lettuce. Lactuca sativa and its forms belong to the long-day plants. Flower formation is stimulated as soon as the day length exceeds twelve hours. This is the case from June to August. The central shoot stretches and branches from a height of 50 centimeters into a loose inflorescence.
That's why lettuce shoots prematurely
If flowers develop prematurely, growth has been negatively affected by stress factors. If the planting distance in the bed is too small, the lettuce plants compete for light, so they shoot up early. If the soil is too dry, a stressful situation also arises. The plants try to produce seeds as quickly as possible before they die due to lack of water. The same applies to temperatures that are too high. More rarely, an insect infestation on the roots can lead to sprouting.
What you can do
Please note the specified sowing dates, which vary depending on the variety. When planting lettuce, pay attention to the spacing so that the plants have enough space to grow undisturbed. Plant vegetable salads in loose, deep soil that is not too heavy. Humus-rich and nitrogen-poor substrates are optimal.
Choose the right varieties
During the summer months, successful cultivation is more difficult when the day length is over twelve hours. There are now a number of so-called day-neutral varieties that are not based on the number of hours of light. They do not tend to shoot and are designed for summer culture.
Solid lettuce varieties:
- 'Ovation': can be sown from February to August
- 'Lucinde': Sowing takes place from mid-March to the end of August
- ‘Pirate’: Seeds are allowed in the bed from April to June
- 'Brown Defiant Head': Direct sowing between April and June
Harvesting lettuce
Usually the lettuce plants are cut off completely as soon as a strong and juicy head has formed. If you harvest individual leaves from the outside in and leave the heart intact, the plant will grow back steadily. Harvesting is possible until flowers form. As soon as inflorescences appear, the plants store bitter substances in the leaf mass. The salad is still edible. Before preparing, remove the bitter stems and check how tough the leaf tissue is.
Tip
Harvest the lettuce in the afternoon or evening, as the nitrate content is higher in the morning than later in the day.
