Katuk is native to the lowland, rainforest understory of the warm tropics and is a familiar plant in home gardens from the wetter parts of southeast Asia
This perennial plant is popular for its edible leaves and young shoots as well as for its ability to survive under hot and humid conditions even occasional flooding. If shoots are planted close together with additions of manure and some shade, the bushes will form a hedge of edible leaves for year round consumption by families or for commercial sale.
Katuk will tolerate acidic soil, heavy clay soils, shade and frequent pruning of its young shoots. Shoots can be regularly pruned close (6 in;15 cm) from the ground; young shoots are tender and tasty. Since the preferred crop is the foliage, the plant requires nitrogen fertilizer to promote rapid regrowth after harvest. Mycorrhizal fungi form a beneficial fungus-root association enabling the plant to extract phosphorus from the soil more efficiently.
Harvesting and Seed Production
Katuk can be propagated from cuttings or from seed. Make an 8 in (20 cm) cutting from the part of the stem where the bark is intermediate between green and brown. If propagating by seeds, please note that germination is very slow (as log as several months), so plant the seeds and wait patiently. Germination time of Katuk seeds is variable. Seeds can be harvested and kept dry and cool when in storage.
Pests and Diseases
Katuk has minimal pest and disease problems. Minor pests include the Chinese rose beetle (Adoretus sinicus) and slugs. In northern Thailand, there are reports of root rot under excessively moist conditions and suspected nematode problems. Slugs that girdle the stems and kill the plant can be a problem in rainy climates. The beetle eats the leaves of young Katuk but the bush is not greatly affected and continues to produce leaves.
Cooking and Nutrition
A ½ cup (100 gm) serving of fresh Katuk leaves supplies 22% of the daily requirement for vitamin A and is a substantial source of vitamin C (138% of daily requirement). It also has value as a source of calcium and iron; elements often lacking in diets that do not contain enough milk. The new growth as well as the flowers and small fruits are all used for food. The fact that the greens retain their color and firmness when cooked make them valuable for sale to restaurants.