Well, you asked the right person. I grow roses & perennials very successfully now, but it has taken alot of work. We would take a 4' x 8' section, dig out the sand to about 3' deep, haul it away, then bring home compost by the yard & mix it in thoroughly. We've done this section by section until we got the whole area inside the fence done. Each year I've had to add more compost as it does settle into the sand underneath. Lots of work, but well worth it!!

John----Where do you live? Proper root stock might have a LOT to do with your roses.

My home and yard sit on sandy glacial moraine. Unamemded soil is just plain yellow sand with little if any organic material. By using organic fertilizers, lots of horse manure, not picking up lawn clippings, and lots of mulch, I've managed to create a sandy loam that goes down 6-8 inches. I've not hauled in any soil from elsewhere. Each planting hole is amended with compost, manure, leaves, dead birds, rabbits, pets, (BTW my little black kitty that got run over is buried under a rose bush in my garden.) road kill, or anything else that will decompose and enrich the soil.
(If I had my way, I'd wish to be buried in my rose garden in a biodegradable container so I could go back to nature as is intended in the circle of life.)
Water drains quickly so I water early day, beginning at 4 A.M., in each of eight zones. I also have a fertilizer injector attached to the watering system that injects a dilute fertilizer each time I water. A little fertilizer often is better than a lot all at once. It keeps a steady supply of nutrients available all the time for even growth and constantly replaces those lost through leaching out.
If you have fast draining sand, you need to water deeply and often, and supply slow release fertilizers such as manures or organic types like Mill's Magic that will add to the composition of the soil and not leach out like chemical types do. Organics increase the water holding capacity of the soil as it enriches it. They must be added often as they tend to be less effective as they break down and release their nutrients. I don't rake up or burn leaves. I mulch them in the yard and leave them for the worms to work into the soil. Running over large piles of leaves with my garden tractor's mulching blades cuts the leaves into very fine particles which quickly disappear into the grass. I try to get as much of this into the rose beds as I can. I try to use my brain instead of my back and let Mom Nature help me by encouraging what happens naturally if we don't interfere in the processes.

Raised beds of good soil might be an option as well if you don't want to dig up what is already there.

If you are in Florida, Florida has a type of nematode that damages rose roots. To deal with that, Florida rosarians use a different type of rootstock that that used in other parts of the country.

dust to dust eh?
There is a certain beauty in that idea Karl.

ken, i'm lake front in hamburg, michigan. JOHN