Our climate is very mild (average high/low for July was 22°C/18°C) but I make a point of watering plants in pots in the morning (like 8am which is early for me). I water them carefully and thoroughly early in the day (done before noon guaranteed), so that by the afternoon they have lost all the extra moisture through gravity, and the first night the soil is on its way to drying out again.
Whether that time is actually better would be subject to experimentation that I have not performed.
I am curious to hear everyone's opinions on this.
My thinking is that given the cooler temps in the night (and >90% humidity most nights here in July) I'd like the container plants not to be sitting in water at that time.
For plants in the ground I have the exact opposite approach, which is to water at twilight and hope that I lose less of my effort to evaporation that way (drainage in the actual soil around the plants being nearly perfect, as it is mostly sand and rock).
