By Yrp
United Kingdom 
I have a patio where every year I grow flowers and herbs. I noticed last year when we were bakc from holidays the plants, specially the petunias look very sad, despite someone watering them every two days. So, appart of watering them I started spraying them with a steamer. This revive them and look great for the rest of the season. I have started doing that now maybe too prematurely and some of the leaves (not flowers yet) are starting to show white spots. Have I start doing this too soon (I stopped now) or it is unrelated?
Thanks
23 Apr, 2015
Answers
Are the white spots fluffy and sitting on the surface of the leaf? Or within the leaf tissue, like a small burned or whited out area? A photograph would be very useful - if the spots are the first type, some treatment is probably required.
Either way, don't use this method - the only reason your petunias responded well last year was because of the particular circumstances, that is, they'd gone short of water while you were away. That might mean the person who was watering didn't do it often enough or didn't give a good soak each time, or it was hot and windy and they needed watering daily, if not twice daily.
Given they're not yet at the stage where they might dry out, just water normally.
23 Apr, 2015
I've never heard of anyone using a steamer on their plants. You may have scorched them. Did you harden them off before putting them out? There are still pockets of frost around. Anyway I bet they are germ free if nothing else! :)
23 Apr, 2015