Watering window boxes twice a day?

I haven't planted mine out yet, a task for this weekend.

Your DH is right Callistemonwatering in sunlight can singe the leaves badly so always better the do the last water when the sun has gone down,at the moment I water my baskets and tubs early morning and after 7pm and they look good and healthy.

You have to be careful not to get water on the leaves if you water in sunshine.

Apparently, according to DH.

I need to do the afternoon watering because the plants are actually collapsing at that time. If I left it until the evening they probably wouldn't recover.

I only water pot plants once a day of every other Day be careful you don’t over water the top compost can look dry

I agree water them in the late evening then they will be damp all night.

Everything is very dry with the warm weather and a breeze.

Pelargoniums don't mind being dry, one reason why I like them. I think fuschias and verbena prefer more moist soil.
Can you leave the 2nd watering until a bit later after the sun has gone down?

I'm hoping we will get some rain soon, preferably overnight.