What do you want to spray them with?
Black Spot. This fungus disease is most common in humid and rainy conditions; the fungus spores germinate in water. Once a plant is infected, the fungus will remain in the canes through the winter and reappear on the next season's growth. Many of the HT's have poor resistance to it, but it is controllable with good sanitation in and around your bed. Same with powdery mildew. If you live in a humid area, it goes with the turf.
Normally, it's suggested to use fungicides to control. I don't use chemicals, I do however, use sanitation practice, pick roses that are highly resistant, and work on improving the health of the soil in my beds. I only have 3 HT's left, they were all Mother's Day gifts many moon ago and are about 25 years old. Which is the only reason they are still here. I have gone almost exclusively to rugosas and antique roses. They are just a lot easier to care for and I love the fragrance and the hips. I do use a cup of corn meal around the base of my roses first thing in the spring. That does seem to help, how it works, I have no clue, but the worms love it, I also periodically dig in a banana peel around the bushes. The worms love those too, so the soil is very rich and friable.
Hope that helps.