Hi Einin Dee
Thanks for your comments regarding bloom life of Oklahoma in hot and humid summers. I also grow Oklahoma in Islamabad that has a climate similar to US zone 9b with an addition of monsoon season. During hottest part of summers, temperature in Islamabad can reach up to 45*C but generally stays like 39 to 43*C, During these hot days, my Oklahoma blooms lasted for 1-2 days which is a very good bloom life in such high temps. I am 100% organic. I think Malaysia temps during hottest months in Malaysia rarely cross 37*C and generally stay in the range of 32 to 34*C. I wonder what caused your Oklahoma blooms to scorch? Do you recall the temps in those days when it was occurring?
Below are 2 photos of the same bunch taken with a gap of 48 hours. As you can see, Oklahoma shows a very good bloom life in very high temps in which blooms of most other roses fry out.
best regards