For sowing or planting lettuce outdoors, it is crucial that the surface (seedbed) layer is of fine crumbly structure. On heavier soils and extremely sandy soils, it is recommended to incorporate peat into the surface layer to improve structure and better retain moisture.
Crop Rotation for Lettuce
Although lettuce tolerates being grown in the same location fairly well, it is necessary to avoid long-term cultivation on the same area. It is advisable to have at least one preceding crop from a different family.
Due to the short vegetation period of lettuce, it is possible to grow 2 – 3 crops annually, and lettuce is often grown as an intercrop.
Growing Lettuce Outdoors
Lettuce seedlings are planted in moist soil and watered immediately to ensure good rooting. They are planted shallowly up to the root collar, which should not be left above the soil surface (a preventive measure against the onset of lettuce rot). The planting distance depends on the cultivar’s vigor and the possibility of using mechanization for planting, as well as potential subsequent inter-row cultivation. Cultivars that develop a smaller rosette (e.g., early spring butterheads) are planted at a distance of 20 x 20 cm, while more vigorous ones are planted at a distance of 30 – 40 cm between rows and 25 – 35 cm within the row.
The timing of sowing and planting lettuce outdoors depends on the length of the cultivar’s vegetation period, market needs, and the climate of the area where the lettuce is grown. Possible or indicative schedules for the continental and Mediterranean areas are provided in the following table, which is taken from the book “Vegetable Growing” by R. Lešić and colleagues.
Continental Area
- Sowing: February (2nd week), March (1st week), March (3rd week), April (1st week), May (1st week), June (1st week), July (1st week), August (1st week)
- Planting: March (3rd/4th week), April (1st/2nd week), May (1st/2nd week), June (1st/3rd week), July (1st/2nd week), August (3rd/4th week), September (2nd/3rd week), October (1st/4th week)
- Harvest: May (1st/2nd week), May (3rd/4th week), June (1st/3rd week), July (1st/2nd week), August (1st/3rd week), September (2nd/3rd week), October (1st/4th week), November (2nd/3rd week)
Mediterranean Area
- Sowing: January (3rd week), February (3rd week), March (1st week), March (3rd/4th week), April (1st week), May (1st week), June (1st week), July (1st week)
- Planting: February (4th week), March (3rd/4th week), April (1st week), April (4th week), May (1st/2nd week), June (3rd/4th week), July (1st/2nd week), August (3rd/4th week)
- Harvest: April (2nd/3rd week), May (1st/2nd week), May (3rd/4th week), June (1st/2nd week), July (1st week), August (1st/2nd week), October (1st/3rd week), November (2nd/3rd week)
