Spring onion yellow Tosca

Allium cepa - Tosca

Onion is an ancient vegetable originating from Central Asia, known even to the ancient Egyptians and Sumerians. It contains many elements - iron, zinc, magnesium, phosphorus, potassium, sodium, calcium, copper, sulfur and even a little iodine. It also contains folic acid, vitamin C, E and a range of B vitamins.

There are several types of onions - winter onions, shallots, pearl onions and the aforementioned kitchen onion. Just choose and start growing!

How to Grow Onions

• Requires a sunny location, but not direct sunlight. The soil should be permeable, well-worked with sufficient nutrients. Shade doesn't suit it. The plant has the greatest watering requirements after sowing and when the bulb is forming. In humid weather, we don't recommend watering in the evening. There is a risk of attack by onion downy mildew. We don't recommend growing onions in the same bed for 4-5 years to reduce attack by pests and diseases.

• Direct sowing: spring sowing starts from March to April. Rows should be 20-30 cm apart, sowing depth 15-20 mm. We sow winter varieties from August 20th to the end of the month. The onion should develop 3-4 leaves before winter. We harvest winter varieties from May to June.

  Sowing sets: onions are not peeled. Before planting, they must be soaked in e.g. Rovral 50WP or Rovral FLO. We plant at the end of March. We plant in rows 25-30 cm apart. The distance in rows should be 10 cm, sowing depth 4-6 cm.

• Onions thrive best in permeable, nutrient-rich sandy-loam soils. Optimal pH 6.5.

• Onions have a short growing season and therefore don't need many nutrients. They don't tolerate direct manure fertilization. Before sowing or planting, fertilize with 80g N, 30g P and 100g K. In the 2-3 leaf development phase, 30g N as nitrate. During the first fertilization - before sowing - we apply the most nitrogen, but the lowest proportion of P2O5 and K2O. Onions are demanding on sulfur, which we apply in the form of potassium sulfate. We can use special fertilizers designed for allium plants.

• Plants are attacked by onion flies, which lay eggs at the neck of plants. The hatched larvae devour the plant. We control them with Diazinon or Sumithion preparations. Onions grown from sets are sensitive to attack by onion thrips. They lay eggs on the leaves of emerging onions. These then curl and the plant subsequently slowly dies. We preventively control this pest during planting by covering the bed with non-woven textile. If we haven't applied textile, one of the preparations Sumithion, Karate or Dragon will help.

  In humid weather, there is a risk of attack by onion downy mildew. It manifests as yellowing of leaves and brown spots. Leaves die and the onion rots. We eliminate the disease with Novozir or Kuprikol.

• We harvest onions when the foliage begins to yellow. The stems start to bend to the ground. Then we pull the onion out by the foliage and can leave them to dry on the bed for one to two weeks.