Water Spinach Sow from March to end of July in open ground. Plant out 25cm apart with 25cm between rows. Harvest when the plant is 30cm high, by cutting just above the ground. Let the plant regrow, as it can be harvested several times. Keep it well moist. You can cook or stir-fry the water spinach. The taste resembles spinach but with a more intense flavour. The young stems are also edible.