Cotton ...
I am gardening in non-fertile soil and found that I needed to add chelated iron to my feeding program. The iron helps the plant form chlorophyll which helps the foliage to grow more densely and I found the actual leaves were larger so that there was more leaf surface for photosynthesis. All good.
I grow 100+ roses in high heat and once established, only water each rose deeply once a week. The roots follow the water. With deep roots that have access to moisture that doesn't evaporate quickly, the plant is more heat resistant.
The first year you may see your rose kind of wilting in the afternoon. That is just because in high heat, the transpiration rate ...loss of moisture through the leaves ... is too great for the young root system to send enough moisture up during the day to keep up with the moisture loss through the leaves. Generally, by the second or third year, you won't see this happening with your roses.
Good luck.
