Hi Mike, This may not be much help coming from "usually" cool Coastal MA but, I would think that getting them in the ground sooner would be better. Where you are only getting 2 plants, it probably wouldn't be too hard to put some screening from the sun if you should have a really bad spell. I'm a believer and a user of the sideways lawn chair with the back over the plant to shield it! I've done it with Rhodys that have been moved to a new location and haven't become acclimated to their new surroundings as well as hydrangeas. The chairs are so easy to move too as the sun moves. Not exactly the scientific approach but it does work. Your plants will need as much time as possible to get a good root system going for gorgeous flowers for next year! This is just my opinion, I'm sure there will be others who live in your area that may be more helpful!

Good luck,

Donna