If you are going away and will be unable to attend to your baskets / window boxes for 2 – 3 days MAXIMUM here is what you should do.

Soak you baskets / window boxes of flowers in a basin of  LIGHTLY suddy water ( NOT ANTIBACTERIAL OR SCENTED) After a soak time of about 12 hours, bring the baskets / window boxes of flowers indoors to a cool room. This will protect them from the effects of sun and wind while you are away. Upon your return, rehang your baskets / windowboxes and water them well.