How Long Is the Growing Period of Napa Cabbage? Harvest Time and Fertilization Methods Explained
Napa cabbage is a vegetable native to China, also known as heading cabbage and hearting cabbage, and it is cultivated throughout both northern and southern regions.So how long is the growing period of napa cabbage? When is it harvested for market? How should it be fertilized?
How long is the growing period of napa cabbage?
1. The growing period of napa cabbage is about 55 days.
2. Napa cabbage is a biennial plant, but when sown in early spring it can also flower and set seed in the same year, behaving as an annual. The growth and development cycle of napa cabbage is divided into two stages: vegetative growth and reproductive growth.
(1) Germination stage. Under suitable conditions it takes 5-7 days.
(2) Seedling stage. It takes about 16-20 days.
(3) Rosette stage. Early-maturing varieties take about 15-20 days, while late-maturing varieties take about 25-28 days.
(4) Heading stage. Early-maturing varieties take 25-30 days, while mid-to-late-maturing varieties take 25-50 days.
When is napa cabbage harvested for market?
Depending on the variety and region, the planting and harvest times of napa cabbage differ.
1. Spring cabbage: sown in autumn, the seedlings overwinter and the mature plants are harvested the following spring; when sown in early spring, the seedlings are harvested. Those sown in cold frames in early spring or sown after the Spring Equinox can also be harvested as mature plants.
2. Summer cabbage: mainly grown for harvesting young plants, it can be sown at any time from early May to early August and harvested continuously.
3. Autumn and winter cabbage: raised as seedlings and transplanted, mainly harvested as mature plants. In South China, sowing takes place successively from September to December, with harvests staged until February of the following year; in the Jiangsu-Huai region, sowing takes place successively from early August to mid-October, and the harvest is completed before the soil freezes.
How should napa cabbage be fertilized during its growing period?
1. Applying seedling-promoting fertilizer during the seedling stage. From the unfolding of the cotyledons to the emergence of true leaves and up to 8-10 leaves, about 15-20 days constitute the seedling stage. Growth is relatively fast at this time, and it is also the period when root and leaf cells and tissues differentiate most rapidly. Although the nutrient demand is not great, a deficiency greatly affects the later yield. Therefore, after thinning to a stand, 10 kg of ammonium nitrate should be applied per mu.
2. Key topdressing during the rosette stage. After napa cabbage enters the rosette stage, the root system develops extensively, growth increases sharply, and nutrient uptake is high. The leaves that produce nutrients during the heading stage have basically fully grown by this stage, so vigorous growth during the rosette stage plays a decisive role in the growth of the head. This stage is the key period determining how well the head forms later. The rosette stage generally lasts 20-25 days; apply 15 kg of ammonium nitrate per mu, together with a certain amount of phosphorus and potassium fertilizer, to promote the growth of the outer leaves and lay the foundation for good heading.
3. Topdressing during the heading stage. The heading stage accounts for 1/2 of the growth period and 2/3 of the total growth, and it is the critical period for head formation in napa cabbage. If fertilizer runs short at this time, it directly affects the tightness of the head and affects yield and quality. In the early heading stage, the outer leaves near the heart leaves continue to grow, and it is also the period when the 1st to 5th heart leaves grow fastest; at this time, generally 15 kg of ammonium nitrate is applied per mu. In the mid-heading stage, the outer leaves almost stop growing, and 10 kg of the quick-acting fertilizer ammonium nitrate is applied per mu. In the late heading stage, because of short daylight and low temperatures, plant growth is slow and nutrient uptake is low, so the effect of topdressing is not obvious, and little or no topdressing may be applied.