u/melissaphobia

I’m new to growing roses this year. I bought 3 varieties from David Austin and planted them in planters on my roof deck. Two are doing pretty well as far as I can see. The desdemona has this red new growth that makes me wonder if it’s Rose Rosette, but I’m not sure . Since I’m a newbie I figured I’d ask you guys what you think this is and what I should do.