a better way to spray
This might be a better way to spray your flowers. It seems to work for me.
This time of year, the red spider mites move in on the dahlias in a serious way. Thrips can so mess up gladiolas that the flowers won't even open. Earwigs can destroy buds during any month of the growing season. Any bugs on any flower can wreck its cosmetic value. And, cosmetic value is all that a flower has going for it (poor thing ;o).
Flowers present a special problem for insecticide use. We worry about "leaf burn" when spraying plants in bright sunlight. The problem must be worse with every foot in altitude. And, I've seen a fruit tree drop every leaf when sprayed with soap at the wrong time of day. But with a flower - you burn the petals - - easily! It isn't such a great trade-off to rise to your plant's defense only to lose the flowers that you were hoping to enjoy. And, just about any spray that I've used has burned flowers.
My past technique has been to spray as close to sunset as I can schedule. What I've been doing lately is to spray right at mid-day . . . !!
The difference is that the plants are well-watered, dried a little, and then sprayed.
It takes me quite a few hours to complete my irrigation chores. It usually doesn't take long for the plants to dry during the growing season - - then I spray.
The flowers have had almost zero burn doing things this way.
I'm not talking about "hosing them down" first. I've done that for years - washing the spider mites off dahlia plants and then spraying. I suppose it helps the burning some. But, I'm talking about a thorough soaking of the soil as you are probably doing once or twice a week, anyway. Spraying immediately after with no concern about where the sun is in the sky has worked for me.
Just my 2ÃÂ¢ on the subject . . .