Spring Yellow Onion Long Tosca

Allium cepa - Long 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.

We know several types of onions - winter, shallots, pearl onions or the aforementioned kitchen onions. 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 bulbs are forming. In wet weather, we don't recommend watering in the evening. There is a risk of downy mildew infection. We don't recommend growing onions in the same bed for 4-5 years to limit pest and disease infestation.

• Direct sowing: spring sowing begins from March to April. Rows should be 20-30 cm apart, sowing depth 15-20 mm. Sowing of winter varieties is done from August 20th to the end of the month. Onions should develop 3-4 leaves before winter. Winter varieties are harvested from May to June.

  Planting sets: onions are not peeled. Before planting, they must be treated with e.g. Rovral 50WP or Rovral FLO. Planting is done at the end of March. We plant in rows 25-30 cm apart. Distance in rows should be 10 cm, planting depth 4-6 cm.

• Onions thrive best on 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 fertilization with farmyard manure. Before sowing or planting, fertilize with 80g N, 30g P and 100g K. In the 2-3 leaf development phase, 30g N in nitrate form. During the first fertilization - before sowing - we apply the most nitrogen, but the lowest proportion of P2O5 and K2O. Onions are demanding in sulfur, which we apply in the form of potassium sulfate. We can use special fertilizers designed for sulfur-loving plants.

• Plants are attacked by onion flies, which lay eggs at the neck of plants. Hatched larvae devour the plant. We eliminate them with Diazinon or Sumithion preparations. Onions grown from sets are sensitive to leek moth infestation. It lays eggs on the leaves of emerging onions. These then curl and the plant gradually dies. We prevent this pest at planting by covering the bed with non-woven fabric. If we haven't applied fabric, one of the preparations Sumithion, Karate or Dragon will help.

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

• We harvest onions when the tops begin to turn yellow. The stems begin to bend toward the ground. Then we pull the onion out by the tops and can leave them to dry in the bed for one to two weeks.