The transplanting should be performed on cloudy or rainy days, when the soil is very damp. The rows are of 30 x30 cm spacing. Mint requires considerable amount of water during the entire period of growth, except at harvest time. It cannot withstand a long period of drought. It is, therefore, recommended that mint be grown in the rainy season unless supplemented water can be provided.
Rainy season has certain effects on the growth of the mint plants and the yield of oil.
Luxuriant growth is expected but the oil percentage of the fresh material is relatively low. On the contrary, mint grown in the dry season through irrigation yields low fresh material but high percentage of oil. Other than rain water, several systems of irrigation are practised in mint cultivation in Thailand, viz. Furrowing, flooding, watering through the use of special equipment, pump, or sprinkler. Although mint requires a considerable amount of nutrient, chemical fertilizers are not commonly applied by the mint growers since they are costly and the response is comparatively low.