When is best time to water garden?

Best watering time in general is early morning or mid afternoon. This means that less water is lost through evaporation in the morning (and is therefore available to the plant).

Watering mid afternoon ensures that the soil is only slightly damp in the evening and not wet (also not over midday). Wet soil and foliage at night provides the ideal environment for fungal growth (particularly in hot or humid climates). Lawns and grass are particularly susceptible to this.