 You don't water in the evening because there are too much chances that that water is going to sit there and create disease for the plant. So therefore, your best time to water is early in the morning, usually around 5 o'clock up to about 8, 9 o'clock at the absolute most. If you can keep it before that, it's even better. The other thing you want to do is make sure you have plenty of bark, wood chips, or gravel, or compost, or other materials that are on your planter beds to make sure that the evaporation loss is not high.