Planting strawberries in a tunnel

by | Jul 8, 2026 | Project

Forcing Strawberries in Tunnels

To force the strawberry harvest, green and plugplants are typically used in tunnels and placed on raised beds covered with black mulch film. Planting is possible from the end of July to the end of August.

To achieve the greatest possible forcing effect, the tunnel should be closed in mid-February. However, this increases the risk of late frosts. The first rays of sunshine will help the plants begin to grow. If the tunnel is closed earlier in autumn or winter, ensure adequate ventilation to provide the plants with the necessary cold stimulus.

Another way to aid forcing is to cover the plants with fleece from the moment the tunnels are closed. The fleece remains on the plants until they begin to flower and is then removed. Sometimes a double covering of fleece and film is used. The removed fleece is always kept in the tunnel so it is readily available in case of late frosts and can be used to protect the plants.

Facts about forcing
  • Green and plugplants are standard in tunnel cultivation
  • Planting possible from late July to late August
  • Plants per linear meter:
     – Single row: 3-5
    – Double row: 6-8
  • Irrigation after planting is important

 

Delay in Tunnel Cultivation

When planting in tunnels, it’s possible to replant the field after an early harvest for a second, very late harvest. For this, A+ plants (strong plants) or plants from the waiting bed are typically used and planted on raised beds covered with black plastic sheeting. The first harvest period for these plants is in September/October, and the second follows in spring.

One disadvantage of this cultivation method is that the later the harvest in autumn, the shorter the dormant period. This can result in the plant having less time to develop new flowers, and consequently, a smaller harvest in spring.

 

General Information on Plant Cultivation

Strawberries are primarily cultivated in tunnels using raised beds. The beds are covered with black plastic sheeting and result in slightly earlier ripening compared to direct ground cultivation. When using raised beds, the beds can be planted in single or double rows. The planting distance should be approximately 25 cm, with 3-5 plants per linear meter recommended for single rows and 6-8 plants per linear meter for double rows. The recommended planting density for green and plugplants is approximately 4-6 plants per square meter.
An irrigation system with drip hoses is required for optimal water and nutrient supply. Since the focus of measures in tunnel cultivation differs somewhat from that in open fields, individual fertilization plans and plant protection measures are necessary and should be developed in consultation with a professional.
In cooler temperatures, the plants in the tunnel can be protected with a fleece cover; sometimes a double fleece cover is used.