Dutch strawberry technology
Fragrant strawberries in Russian beds have become a real symbol of the coming summer. But it is unlikely that it will be possible to feast on domestic berries at other times of the year. But in the malls all year round they offer products from Greece, Serbia, countries of northern Africa, the Mediterranean and Holland..
What technology for growing strawberries, even in areas where the climate cannot be called mild and warm, gives such good results?
Features of Dutch strawberry cultivation technology
In the middle lane, you can accelerate the ripening of the strawberry crop in the country with the help of greenhouses. But getting a berry in any season and practically without a break is possible only under the condition:
- growing in heated greenhouses with controlled temperature conditions;
- plant feeding;
- creating a proper lighting and watering regime;
- competent selection of seedlings and maintaining its stock for renewal of plantings.
It is in the Netherlands that this technology for growing strawberries in a greenhouse is most widely used. Local farmers supply most of Europe with berries, and forcing-based agricultural technology has become known as Dutch.
The complexities of strawberry cultivation technology all year round
The berry culture bears fruit amicably with artificial lengthening of daylight hours and adherence to a special temperature and humidity regime. But you won’t be able to achieve a stable harvest if you plant new bushes at least once every two months. That is, the technology of growing strawberries all year round presupposes the presence of a serious stock of planting material. If large farms can buy seedlings, then it is more profitable for summer residents to grow them on their own..
The experience of European and Chinese farmers shows that strawberry bushes obtained in the warm season, waiting for the moment of planting in the ground, can be stored at zero temperature for up to 9 months. And if modern remontant varieties are used for forcing, then planting will have to be renewed only twice a year. To increase the efficiency of greenhouse areas, strawberries are actively grown not only on ridges, but also in all kinds of containers, bags and vertical structures, using drip systems for irrigation.
Greenhouse lighting according to Dutch technology
When using the Dutch technology for growing strawberries in a greenhouse, special attention is paid to additional lighting, in a spectrum close to sunlight. Luminaires are placed a meter above the plantings, and reflective materials are actively used to increase the efficiency of lighting in the greenhouse..
Strawberries respond well to an increase in daylight hours up to 12-16 hours:
- plants can bloom within 10 days;
- the beginning of fruiting will be on the 35th day.
Additional lighting is effective in the morning and evening hours, but if the weather outside the greenhouse is cloudy, then the lamps can be turned off.
Irrigation system based on strawberry cultivation technology in a greenhouse
The drip system provided by this technology, whether it is surface or subsurface irrigation, does not allow moisture to get on the leaves and other parts of the plants, and all the water goes strictly as intended..
- This prevents the development of infections and diseases of the berry culture..
- Drip irrigation saves moisture and strength of the summer resident.
- Preheating irrigation water helps save energy and speeds up harvesting.
- Through the irrigation system, you can apply the necessary fertilizers and top dressing under the strawberries.
Since water enters under the roots, the soil does not become waterlogged and does not dry out. And the subsurface system contributes to additional aeration of the soil under plantings.
Soil preparation for strawberry seedlings
Intensive, year-round fruiting of plants is impossible without nutrient-rich soil.
Companies operating on Dutch strawberry cultivation technology use a variety of substrates.
In suburban conditions, you can prepare a mixture of:
- loamy sod land, rich in organic matter, but having a slight acidity;
- sawdust moistened with a solution of urea, added for looseness at the rate of seven parts to two parts of the earth;
- glasses of wood ash, chalk or dolomite flour;
- low-lying peat, which absorbs and retains moisture well, and before adding copper sulfate soaked in a solution with mullein to the mixture;
- humus from the decomposition of organic residues or manure;
- river coarse sand, introduced in the amount of 10% of the volume of the prepared mixture.
Before filling containers for planting strawberries, the substrate is well stirred, choosing foreign inclusions.
Microclimate in a greenhouse for forcing strawberries
According to the technology of growing strawberries all year round, the optimal temperature range is from 18 to 25 ºС. Only at the moment of mass ejection of peduncles is it better to maintain the temperature up to 21 ºС.
- Low temperature inside the greenhouse can cause prolonged flowering and uncooked harvest..
- An excessively high background adversely affects the ability of plants to pollinate and set berries..
Strawberry bushes react extremely negatively to the temperature drop below 12 degrees and its rise to 35 ºС. The air humidity in the greenhouse must be maintained within 70–80%. If the air is dry, spraying is necessary. Excess humidity is reduced by ventilation.
To accelerate the growth of seedlings and bring fruiting closer, experienced summer residents monitor the level of carbon dioxide in the greenhouse. To increase it to 0.1%, you can light candles.
Growing planting material
You can prepare planting material for greenhouse cultivation of strawberries in different ways:
- Young plants are grown on the mother plantation until late autumn, and with the arrival of frost, the rooted whiskers are carefully dug out, cut off the foliage and stored with an open root system in cellars or basements at temperatures from 0 to +2 ºС. The day before planting in the greenhouse, the seedlings are removed from the storage for acclimatization and sorted. The advantage of this technology for growing strawberries is the root system developed in the seedlings, and the disadvantage is the need for large uterine plantings, which also need to be updated in two years..
- Seedlings obtained by the cassette method are sent to storage at temperatures from 0 to +1 ºС and humidity of 95% in the form of young whiskers. Six weeks before being transplanted into the greenhouse, they are removed and planted in small containers of nutrient soil. The containers are shaded for 4 weeks while there is intensive root formation. The plants are exposed to the light in the fifth week, and in the sixth – they are planted in the greenhouse..
Planting strawberries in a greenhouse
Dutch technology for uninterrupted growing of fresh berries involves the use of a variety of containers for planting plants. These can be cut-hole polypropylene pipes, pots and plastic bags and containers..
The main thing is that the containers placed vertically or in several tiers have a volume sufficient for the root system, and the plants receive the required watering and lighting..
One of the practical solutions is a plastic bag, up to 2 meters high, so that picking berries is simple and convenient, and with a diameter of at least 15 cm.After 25 cm, cross-shaped cuts are made on the surface of the bag with the substrate in a checkerboard pattern, where the seedlings are planted.
When planting in boxes or containers, it is important that the plantation is not thickened and well ventilated. This will prevent the development of a putrid infection and will positively affect the quality of the berry..
The technology of growing strawberries all year round is good when using self-pollinating varieties of berries, otherwise the summer resident will have to pollinate with a brush, fan, or, if space permits, put a hive in the greenhouse.
Despite the apparent hassle of such berry cultivation, the costs quickly pay off, since even in the cold season, up to 50 kg of fresh strawberries can be harvested from a square meter of the greenhouse.