Growing spinach under cover in polytunnel GUIDEBOOK SERIES ON TUNNEL CULTIVATION
SPINACH Spinach is an attractive looking plant with a green leafy foliage and tasty flavour. As part of salads, decoration of dishes and nutritious additive, it is an indispensable ingredient for many appetizing recipes. Spinach leaves contain many valuable microand macro-nutrients, vitamins A, C, B1, B2 and E, iron, potassium, magnesium and folic acid. Varieties in spring, summer , autumn as well as winter, are characterized by different taste and texture – and enable planting throughout the year. The best are the youngest leaves cut fresh in the garden, so do not leave the spinach too long in the soil, as it loses a lot of flavor. In contrast, growing in a foil tunnel allows the spinach to ripen much faster and more profusely.
SUNLIT PLACE To grow properly, spinach needs a lot of light, so it should be planted in sunny areas. Of course, you can grow it with a little shade, but it will need a lot of care and, in a really dark place, the plant will focus on producing seeds and become unpalatable.
RESISTANT TO COLD
Spinach is cold resistant. Even at - 7 ° C the plant matures, and the growing process continues.
FIRST IN SPRING Thanks to its exceptional strength, the first blooming in gardening tunnels appear quickly, helped by longer spring days or fine autumn weather . These properties contribute to the fact that many gardeners and farmers plant spinach as a fore crop.
HOW TO GROW SPINACH
SOIL FOR CULTIVATION
SOIL FOR CULTIVATION Substrate for spinach must be drained, damp, neutral. A fertilized soil, rich in calcium, with a heavy structure, Â gives the plant optimum conditions for ripening. PH should remain between 6.5 and 7.0. Spinach should be grown in the first or second year after composting, and the site should contain a lot of peat, composted bark and a high dose of calcium. Prior to planting, the soil should be thoroughly cleared of weeds - spinach leaves are delicate, and the presence of rivals may hamper its maturation.
PREPARING SPINACH SEEDLINGS Fill up small pots with compost and soil mixed with sand. Three seeds are placed in each container. When the first emergence occurs, the most vigorous leaf is left, so that each pot has one plant. 6 weeks after sowing, they are planted in a foil tunnel. Spinach stems expand on the ground, needing a lot of space so they do not overlap each other. It is recommended to plant 4 spinaches in 1 m2 , with a spacing of 60x40 cm. Depending on the season and exposure, spinach needs 3 to 6 weeks to achieve full maturity.
SOWING Sowing spinach under cover directly into the soil can begin in early March, but only in the first half of April for open field crops. Spinach for domestic and field crop is often planted in rows to make full use of the growing space. The second half of September will see the last sowing of spinach , which will  winter and begin to grow when spring is back. Seeds are placed at a depth of 3cm, with a spacing of 20 cm. Between rows, a distance of 40 cm should be kept, but if plants grow too much, they should be restricted. A plant growing in a bulk does not produce the desired leaves but focuses on the release of seed shoots. During the whole process, weeds should be systematically removed.
PLANTING SEVERAL TIMES A YEAR If a grower is going to grow spinach twice a year, planting should occur 6 weeks before the first spring frost and 8 weeks before the fall. We maintain similar distances as for sowing and seedling. It is important to ensure that the plant has the most productive conditions for growth and provide the nutrients it needs to grow properly.
FERTILIZATION Nitrogen fertilizers, manure or fertilizers that release nutrients gradually, should be introduced before planting. For soils less rich in nutrients and minerals, spinach is fertilized with nitrogen , including ammonium nitrate. Depending on your needs, dose can vary from 1 to 3 spoons per square meter once a week for two weeks, constantly in the same proportions. Spinach does not require ammonium sulphate because it causes too much acidification.
SPINACH CARE To harvest spinach more often and get abundant yield, many gardeners are growing in garden tunnels and foil greenhouses. During cold month, the soil is covered with hay, leaves or agrotextile, and when the first plants are out, the cover is removed - except for the agrotextile. This method greatly accelerates plant maturation.
HARVEST This vegetable is harvested from April to December. To operate, equip yourself with a sharp knife that will be used to cut the rosette, which has formed from 5 to 7 leaves. When producing the seedling early in February, giving it time to emerge and then introducing it to the tunnel in March - fresh spinach can be harvested as soon as April. Spinach can be frozen for long term storage, but the tastiest leaves are freshly cut directly from the plant. Avoid blooming leaves as they will taste bitter and be less nutrient-rich. It is important not to tear the rosettes, but to cut it. This will allow the plant to produce new young leaves.
GUIDEBOOK SERIES ON TUNNEL CULTIVATION
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