Strawberries are produced in the open ground and in gutters on racks either in protected - under polytunnels or in greenhouses - or unprotected systems. Independent of the cultivation system, it is always a challenge for growers to steer towards optimal growth to produce the highest yield and quality, the fruits of the grower’s investment can literally be reaped. Choosing the most efficiently formulated fertiliser is vital to achieve that goal. In recent years, protected strawberry cultivation has expanded enormously in the Netherlands. The advice on this page therefore focuses on this system. If, however, you are interested in our advice on other cultivation systems, please contact us.

Select a stage for more information

Stage 1 Planting
Stage 1


Protected strawberry cultivation has various cultivation strategies for different strawberry varieties: day-neutral, everbearing and June-bearing. The variety and strategy used determine to a certain degree the choice of technology, substrate and nutrients. These aspects should be considered and coordinated properly before planting.

Growing strawberries in protected system starts with carefully selected tray plants. The young plants are supplied out of cold storage (-1.5 °C) by specialised nurseries. After the plants have been defrosted, they can be planted in a substrate in pots or gutters.

Soiltech does not have specific products for this stage.

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Stage 2 Root development
Stage 2

Root development

Soiltech does not have specific products for this stage.

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Stage 3 Vegetative growth
Stage 3

Vegetative growth

As soon as the roots of the young plant have penetrated the substrate and the root system starts to develop further, the grower’s attention shifts to the parts of the plant above the soil. During the vegetative growth phase, the plant focuses on the development of foliage, side buds and leaves which grow very close together. For optimal photosynthesis, it is important to stimulate the plants to produce chlorophyll (leaf green). Sufficient sunlight, water, nitrogen, magnesium and manganese stimulate chlorophyll production. The strawberry plant is also characterised by a relatively high iron and calcium requirement at the start of cultivation.

Soiltech does not have specific products for this stage.

Stage 4 Formation flower stalks / flowering
Stage 4

Formation flower stalks / flowering

Flower induction in strawberries is a highly complex process and depends on a number of factors. These include fertilisation, light intensity and irrigation besides temperature and day length. In general, a short day stimulates the production of flowers and a long day the production of stolons (runners). Flowers can also be induced by fertilisation. The elements Molybdenum (Mo) and Boron (B) now become important. Molybdenum helps convert nitrogen into proteins. The ‘computer’ of a plant is controlled by proteins. Molybdenum plays an important role in the production of the right proteins.

In the event of a boron deficiency, the majority of the flowers will develop poorly, leading to insufficient fruit set, misshapen fruit and low production. When correcting the boron levels, pay attention to avoid excessive boron applications. An excess of boron cause toxicity which will be shown as leaf tip-burn (brown coloured leaf edges) when it occurs. In that case, the plant loses vigour.

Soiltech does not have specific products for this stage.

Stage 5 Fruit set
Stage 5

Fruit set

The final strawberry harvest depends on the length of the fruiting stage (this can be limited due to drought stress and/or too high temperatures) and the availability of the necessary nutrients and trace elements, which influence the size, weight and quality of the fruit particularly.

Potassium (K) plays a particularly key role in the accumulation and transport of sugars to the fruit.

Advice in this stage:

Optima Leaf-K: 5 litres/ha Foliar application (every 14 days)

Optima Leaf-Trace: 1 litre/ha Foliar application OR 1.5 litres/ha fertigation (every 14 days)

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Stage 6 Post-harvest
Stage 6


Soiltech does not have specific products for this stage.