Amount of Water

• The amount of water that a rose bush needs is variable. If it's raining on a regular basis, your rose bush will need less water from the water hose or irrigation system. However, if it hasn't rained in several days, give the rose enough water to replenish its reserves. On average, a rose bush grown in a low-humidity, high-heat area will require 6 to 9 gallons of water a week; 1 inch of water or rain yields approximately 3 gallons of water. Use this guideline to determine how much water your rose has received from rain and how much you need to add to the mix.
  
  

The Soil is Important

• Roses don't like wet feet because they are not capable of growing in swampy areas. Even if a space does not appear swampy, if the drainage is poor, then the water cannot move away from an area and the rose may drown. Well-drained soil is highly crucial to the survival of your roses. If your soil is hard and compact or poorly drained, add organic matter to increase its health. On the other hand, roses don't like to be extremely dry either. Without adequate water, they will wither away and die. Adding a layer of mulch over the soil decreases excessive evaporation of the water and increases the health of your rose.
  
  

Recognize When to Water

• Roses that are beginning to wilt need water immediately. However, you shouldn't wait until your roses are wilted before watering, as it causes undue stress to the plant. Fully hydrated roses exhibit lush foliage with perky flower petals. When the water levels of the rose are depleted, the leaves may turn a slight bluish color with a dull sheen, and flower petals will begin to fall off before the flower is fully formed. Check the soil moisture to determine if your rose has enough water. Soil that is overly dry indicates that the rose needs water. If the soil is dry, the rose cannot extract water from it to survive.
  
  

Methods of Watering

• Always water your roses in the early morning or late evening to avoid excess evaporation of the water. During these times, the roses are also open to accepting water and will be able to use more of it. Use a water hose, soaker hose or irrigation system to water your roses, avoiding spraying the leaves and flowers of the rose. Black spots, water-damaged petals and wilted flowers can often be attributed to spraying the rose bush with the water hose, as opposed to watering at the base of the plant.