When is the best time to sow onions?

Onions can germinate normally at a temperature of 13℃-20℃, and the suitable temperature for plant growth is 10℃-25℃. Therefore, the climatic conditions in spring and autumn are more suitable for the growth of onions. Let’s learn in detail when is the best time to sow onions?

When is the best time to sow onions?

The best time to plant overwintering onions varies by region and is as follows:

Northeast China: For colder regions such as Heilongjiang, Jilin, and Inner Mongolia, it is recommended to plant before the White Dew solar term to ensure that the onions have enough growth time before the severe winter.

Liaoning area: The planting time in Liaoning area is around the White Dew solar term, and the climatic conditions during this period are suitable for the growth of onions.

In some areas of North China, such as Tianjin, Beijing, Hebei, etc., the best time to plant overwintering onions is around late September to early October.

In some areas of central China, such as Shandong and Henan, the time for planting overwintering onions is around early October.

Onion Planting Method

1. Soil Preparation

Choose loam plots with fertile soil, good drainage and strong air permeability to plant shallots, and avoid planting in poor or heavy clay soil. Before land preparation, if the soil is too dry, water it thoroughly.

Apply sufficient amount of decomposed organic fertilizer as base fertilizer, 1000 to 2000 kg of high-quality organic commercial fertilizer per mu.

2. Tillage and sowing

Deeply plow the soil and till it several times to ensure that the soil is level, break up large clods, remove small bricks and stones , and loosen the soil. It can be sown in rows or broadcast. When sowing, to ensure uniformity, mix the seeds with fine soil and spread them on the bed surface, then cover them with 0.5-1 cm of soil. Keep the soil moist during the germination period and cover it with plastic film to keep warm and retain moisture. Remove the plastic film in time after germination. Maintain proper plant spacing when sowing, sowing six or seven seeds at about 10 cm. If harvesting seedlings, there is no need to transplant; if you want the chives to grow larger, you can transplant them, keeping the row spacing at 40 cm and the plant spacing at 30 cm.

3. Watering and fertilizing

Onion vegetables have high demands for water and fertilizer, and are especially sensitive to nitrogen fertilizer. Appropriate application of nitrogen fertilizer can increase yield and enhance growth. Lack of nitrogen fertilizer will cause the onion leaves to turn yellow and the tips to dry. At the same time, in order to make the shallots stronger and the white part firm, it is also necessary to pay attention to applying phosphorus and potassium fertilizers.

4. Water and fertilizer management for onion seedlings

The management of onion seedlings is relatively simple. From the time the seedlings emerge to the 3-leaf stage, in order to cultivate strong seedlings and promote root development, do not water unless the soil is dry. Start watering and fertilizing after 3 leaves appear. Apply 5 kg of urea and 5 kg of potassium sulfate fertilizer, or 8-10 kg of nitrogen, phosphorus and potassium compound fertilizer per mu. Generally, apply 2-3 times until the plant grows five or six leaves and is about 30 cm tall. It can be harvested as green onions.

To sum up, the specific sowing time can be appropriately adjusted according to local climatic conditions. A simple way is to refer to the planting times of the past few years. If the planting results were good at a certain time last year and the year before, you can choose to plant in the same time period this year.