Question
my client cannot bend down. I would like to raise a small area(6' x 4') for her to
plant sturdy roses. If i raise it 3 feet surrounded by fencing wood what type of
rocks/sand/soil should I fill it with?
Also you recommend Austins or Rosa fortuniana grafts, where can I find them
and for how much?     We live in Hollywood, Broward Co. Her rose garden against      
a north facing on the south side would get east and midday sun.

Answer
One foot on the bottom can be anything that will drain well such as coarse sand plus soil. The next foot can be any type of garden soil as this is where the anchor roots will be. The last foot is the depth where the feeder roots reside and they need the best soil you can get. Don't waste the rich soil near the bottom it is up near the feeder roots that you want the best. Also sprinkle handfuls of bone meal on the top and dig it in. 3 feet by 6 feet of soil is very heavy so make sure the fencing is strong. if you garden in any place where there are nematodes in the soil then fortuniana is the best understock. However if isn't necessary for any other type of soil. Google Neilsons Roses in Florida and they have a list of the nurseries that sell the roses on fortuniana.
Austins love a warm climate and will do very well for you even Austins that don't do well in cooler climates.