Basically, plants grow well in tap water. Salt water has a higher concentration of salt which means there is a water loss from the plant to the soil in the process of osmosis. Same goes to sugar water as there is a higher sugar content in the soil after pouring the sugar water for the plant. The process osmosis will further dehydrate the plant and no allow the plat to grow IN THIS CASE ONLY. Hot water and cold water is not very 'healthy' for the plant too. Therefore, the plant grows best in tap water.
