Watering: Under normal conditions, roses need an inch of water a week. Sandy soil dries out more quickly than a clay or loam and thus needs more frequent watering, perhaps every 5 days instead of once a week. Adding organic matter, such as Leaf Gro, to a sandy soil can help it hold moisture so that watering is not needed as frequently. It is important to water deeply (12 to 18 inches) but as infrequently as possible to encourage deep roots. Roses with deep roots will be stronger, healthier, and more drought resistant than those with shallow roots. Water early in the day so that the leaves do not stay wet throughout the night, as this fosters disease, especially if you are using an overhead watering system rather than a drip system.