Roses do best with uniform soil moisture throughout the growing season. The general rule of thumb suggests that one inch of water be applied per week during the growing season. The amount and frequency of application will depend on soil type. Sandy soils will need more frequent irrigation than heavier clay soils. Hot temperatures would call for more frequent irrigation, also. The use of soaker hoses in rose beds is highly encouraged. Water can be delivered in adequate amounts while keeping the foliage dry, preventing disease.
The use of mulch around roses to help retain soil moisture is a practice that is highly encouraged. Mulch will also help keep soils cool and help retard weed growth. Materials such as wood chips, straw, or dry grass clippings make good mulches. More decorative materials such as shredded hardwood bark or cocoa bean hulls could also be used. Mulches should be applied about 2-3 inches deep and replaced as needed. Because organic mulches tend to bind up nitrogen as they decompose, additional fertilizer may be needed to prevent nutrient deficiencies.