Early morning is the best time to water your garden, followed by evening after the temperature falls. This is because the midday heat of the sun will evaporate water poured onto the surface before it has a chance to be absorbed into the soil. Morning is better than night because your plants will draw on the water that you add to the soil throughout the day. When you water at night, the water may sit there until the plants "wake up" in the morning and are ready to use it. This is ok, but not ideal as the water that sits can sometimes cause moisture to build up or the leaves of plants to wilt.