Looks like fertilizer residue. Are they recently purchased? Or have you fertilized them?

Yes, may be the fertilizer as I added slow release and recently watered with liquid ferilizer. This is last years plant. I'll back off the feeding for awhile. Thanks.

Use a damp cloth if you want to remove it. If only on the leaf edges, it can also be guttation in very humid locations (the leaves exude water droplets from the leaf edges and after the liquid evaporates, you see some mineral residue). The leaves look quite healthy!

You don't need to remove :-)) Rain or irrigation will wash it off and it does no harm to the plant. Nursery purchases often show this residue.

Oh, my God. You have not met one of my neighbors. That level of "leaf destruction" is not perfection and would not be tolerated in her garden. Hee, hee, hee. She extracted a one-year old rose and replaced it with a new specimen of the same variety due to too much fungal issues!?!?! I told her Molineaux here gets black spot (I have one) but she likes the color and scent.