Kangkong, a green leafy plant with narrow or broad leaves, is native to southern China and Southeast Asia. Narrow-leaved upland kangkong and broadleaved lowland kangkong produce 5- to 6-inch leaves. Only young kangkong shoots are eaten, either steamed, sautéed in oil or canned. Since kangkong is bland on its own, spices are added to enhance its flavour. While kangkong is an important vegetable in many Asian countries, it is not common in the United States. Kangkong is a perennial but grows year-round in tropical climates. However, growing it as an annual decreases the chance of pests and diseases.
Plant kangkong in the late spring. Choose an area with full sun and well-drained soil. Create straight-line furrows 1/3- inch deep with the spade. Space the furrows 6 to 8 inches apart. Kangkong grows in a wet or dry habitat, but dry sowing is easier in most places.
Sprinkle the seeds into the furrows about 2 to 3 inches apart. Cover the seeds with compost.
Give the kangkong 1 to 2 inches of water a week. Add extra water to the kangkong if it starts to wilt by midday.
Mix 0.907 to 1.36kg. of compost with 0.113kg. of nitrogen fertiliser. Spread the mixture around the kangkong when it is about 5 to 7 inches tall. Use 1 to 2 inches of the compost and nitrogen mixture around the kangkong. Mulch over the mixture with an organic mulch about 1-inch deep.
Harvest the kangkong 30 to 45 days after planting. Cut the entire plant to the ground with a sharp, straight-blade knife and allow it to grow back if you want multiple harvests. Uproot the kangkong if you don't care about more harvest. To uproot it, life the kangkong out of the ground by hand.