There are two types of kangkong. Mine is the Upland Kangkong (Ipomoea reptans), which has narrow leaves and adapted to moist soils whereas the low land kangkong (the most common type sold in the wet market) has broader, arrow, shaped leaves. It is adapted to flooded conditions and is harvested several times.
It is one of the most popular leafy vegetables in South and Southeast Asia. It is known by many names including swamp cabbage, water convolvulus, and water spinach. The plant has flowers that range in color from white to pink, and its stems come in shades of green and purple. The leaves are a good source of protein, vitamin A, iron, and calcium.
METHODS OF PLANTING
1. Direct seeding
2. Seedling production
Seedlings can be grown in divided trays or in seedbeds. You can make use of old plastic egg trays or if you have the cartoon egg tray that would be much better. Don’t forget to poke little holes at the bottom of each divided trays. The first method is preferred since there is less damage to the seedlings when they are pulled for transplanting.
If seedlings have been grown in shade, harden them off by gradually exposing them to direct sunlight during the 4–5 days just prior to transplanting. On the first day, expose them to 3–4 hours of direct sunlight. Increase the duration until they receive full sun on the fourth day. Seedlings are ready for transplanting about three weeks after sowing or when transplants have five to six leaves.
Kangkong is ready for harvest in 30–45 days after sowing or transplanting depending on variety and plant type. Plants may be harvested once or several times. For once-over harvesting, plants are uprooted. For multiple harvesting, stems or shoots 15–25 cm in length are cut close to the ground, generally on a weekly basis. Frequent harvesting delays flowering and stimulates growth of side shoots. When plants are not harvested, side shoots develop into longer vines.