21. Water during the early parts of the day; avoid watering when it's windy
Early morning is generally better than dusk since it helps prevent the growth of fungus. Early watering, and late watering, also reduce water loss to evaporation. Watering early in the day is also the best defence against slugs and other garden pests. Try not to water when it's windy - wind can blow sprinklers off target and speed evaporation.