What is the best month to plant kale?

Kale is a biennial herb and a horticultural variety of edible cabbage. One year after planting, the plant will form a rosette of leaves, and after experiencing the low temperatures in winter, it will be able to bloom and bear fruit the following year. Kale is rich in carotenoids . In addition, kale is rich in vitamin C, calcium, magnesium, iron and other minerals, so it is loved by people who pursue health and beauty. So what is the best month to plant kale?

What is the best month to plant kale?

The suitable sowing period for kale is from mid-July to early August, the transplanting period is from mid-to-late August, and the cutting period is from November to December. Sowing too early will cause yellowing of old leaves in the later stage of growth, increasing the difficulty of management and prolonging the management period; sowing too late will cause the temperature to affect the crown diameter of the leaf cluster and fail to reach the required specifications when it is transplanted.

How to grow kale

1. Seedling cultivation method

Kale can be sown in the open air, using two methods: making ridges and growing seedlings in trays. It is important that the seedbed is about 20 cm above the ground to facilitate drainage during the hot and rainy July-August months. Before sowing, an arch shed should be built and plastic film should be prepared so that it can be covered when heavy rain comes to prevent rain erosion and reduce the germination rate.

2. Seedling medium

40% peat soil and 60% perlite can be used as the substrate. Before sowing, spray the substrate layer thoroughly and scatter the seeds directly on the substrate, covering it just enough so that the seeds are not visible. No need to water again after sowing, and cover with a shade net.

3. Management during the seedling stage

After sowing, it is best to use spray equipment to water and keep the humidity of the seedling medium moderate to avoid affecting the germination rate. Seedlings will emerge after 3 to 4 days. Remove the shade net after 4 pm or on cloudy days. During the seedling stage, maintain the substrate pH between 6.2 and 6.5, and apply 50 to 75 ppm nitrogen fertilizer once a week. Generally, no watering is done before germination. The soil in the bed is kept moist during the seedling stage, and the soil is kept wet and dry before transplanting.

4. Cultivation management

(1) Colonization

Kale tolerates poor soil, but grows better in fertile soil. Choose sandy loam or loam that is rich in humus, loose and fertile, and make small raised beds of 100 to 120 cm. The planting time is determined according to the season.

(2) Watering

In the early stage of planting, water needs to be controlled and the humidity should be kept at around 70%. Sufficient water should also be supplied in the middle and late stages of growth, following the principle of not watering unless the soil is dry, and watering thoroughly when watering, to facilitate the expansion of the root system. Too much watering can cause root rot and fungal diseases, while too much dryness can cause the bottom leaves to turn yellow and fall off. After entering the peak flowering period, it is required to keep moist, and reduce the water supply before harvesting.

(3) Fertilization

Kale grows quickly and requires a lot of fertilizer. The plants begin to grow rapidly 5 to 7 days after planting and should be fertilized once a week. When the crown diameter of the leaf cluster grows to 20 cm, change to fertilizing once every half a month. At this time, less urea and more compound fertilizer should be applied. Top dressing should mainly consist of phosphorus and potassium fertilizers, with less nitrogen fertilizer. When closing the ridges, combine it with intertillage and apply 30 kg of diammonium phosphate and 15 kg of potassium chloride per mu. When bolting, apply 35 kg of nitrogen, phosphorus and potassium compound fertilizer per mu. During the flowering and podding period, spray the leaves with 0.5% potassium dihydrogen phosphate and 0.2% boric acid solution once every 7 days.

5. Light and temperature

Adequate light helps the leaves grow quickly and with good quality. The temperature during the growing period is controlled at 20℃ to 25℃ during the day and 14℃ to 16℃ at night. After transplanting, pinching the seedlings when they are 15 cm tall can promote branching. Put up a support net one week after pinching to prevent the flower stems from bending.

6. Pest and disease control

Aphids suck the sap from kale leaves, causing them to turn yellow, curl and become deformed. Prevention and control methods : Use 1500 to 2000 times diluted 50% anthelmintic wettable powder or 3000 to 4000 times diluted 10% anthelmintic, spray once every 7 to 10 days.

Cabbage looper is the main pest of kale. The control method is: after the seedlings are planted, spray them once a week with 1000 times diluted diazinon or 800 to 1000 times diluted chlorpyrifos.

The wilt disease is caused by the fungus Fusarium oxysporum, and the main symptoms are stunted and wilting plants. Prevention and control methods: Soak the seeds in warm water at 50℃ to 55℃ for 10 minutes to kill the pathogens carried by the seeds. Before sowing, disinfect the soil with 1000 times diluted potassium permanganate solution. In the early stage of the disease, spray 800 to 1000 times diluted 70% thiophanate methyl for prevention and control. Severely infected plants should be removed and burned to prevent infection of healthy plants.

7. Harvest

It takes about 55 to 65 days from sowing to harvesting, and 25 to 30 days from planting to harvesting. When 10 to 20 outer leaves have unfolded, the young leaves can be harvested for consumption. 5 to 6 young leaves can be harvested from each plant each time, leaving the heart leaves to continue growing and then harvested one after another. Generally, it is harvested every 10 to 15 days. If managed properly in late spring and summer and there is no cabbage worm damage, harvesting can be carried out until early winter. The flavor is better after a slight frost in autumn and winter. In the hot summer season, the leaves become hard, slightly more fibrous, and have a weaker flavor, so they should be picked earlier. The young leaves harvested in the cool seasons such as early spring, late autumn, and winter have better quality and flavor.

The above is the whole process of kale from sowing to harvesting. Kale is not only a healthy and delicious vegetable, but also has great ornamental value. It is often used in gardens, street flower beds and other gardening work.