By Kitty Belendez, Master Rosarian
Roses are NOT drought tolerant plants. They love water. But, how much water is enough? Well, that’s a tough question to answer. It depends on many factors: weather, soil, drainage, age of plant, size of plant, if the rose is grown in a container or in the ground, if mulch or polymers are used, and sometimes even the rose variety to a certain extent.
We’ve all read in books, guidelines for watering our roses, such as 2-inches per week, or one gallon per day, or whatever. Personally, those guidelines don’t make much sense to me because of where I live. My weather is too erratic, my soil is extremely sandy and therefore drains too fast. Also, I have many miniature roses in containers that are growing in a light growing medium that drains well.
The Weather Factor
Here’s a rule of thumb for how often to water your roses, assuming you have a light to medium soil.
90+ degrees: Every day
80 degrees: Every two days
70 degrees: Every three days
60 degrees: Every four days
50 degrees: Every five days
Now, this is also assuming there is no rain and it’s not windy. High winds can dry out the rose and the soil. In extreme wind conditions, you may have to water or at least mist your roses every day in 80 degree temperatures as they can quickly dessicate.
The Soil Factor
Sandy soils drain much faster than clay soils. Soils with a good blend of organic matter will drain somewhere in-between. Clay soils will need to be watered less frequently than the lighter sandy soils. If you have extremely heavy clay soil, it would be wise to replace the soil in the hole with planter mix when you are planting a new rose bush. So keep this in mind when trying to determine how often to water your roses.
Potted or in Ground
Roses grown in containers usually drain faster than in-ground roses, especially if you have used a light potting soil. Never place a potted rose inside a dish to catch water because roses hate standing in water. The water in the dish will rot the rose roots. During extremely hot weather, container roses usually need to be watered daily.
It’s well worth the money to get your garden set up with an automatic sprinkler system. Learn how to use the timer. Read the manual. Most are really not that complicated once you figure out which buttons to push. If it’s raining, turn the sprinklers to the off position for a few days. As the weather warms up, change the timer to come on more often and for longer periods of time.
The Mulch Factor
Mulch can aid in keeping your soil and roses moist. Several inches of mulch should be applied around your roses at least once a year. I prefer Kellogg’s Gromulch, but there are other brands available. You could use aged horse manure, but be careful of weeds if the horse was free to roam the fields.
Soil polymers such as Broadleaf P4 can aid in retaining water in sandy or very light soils. I wouldn’t recommend using polymers for clay or heavy soils. Potted plants with a light potting soil especially benefit from polymers. These polymers swell up and hold water for extended periods of time, which is especially beneficial in extremely hot climates.
The Bottom Line
Common sense is the most important factor in watering your roses. If it’s hot, they need more water. If it’s cold, cut back on the amount of water. You simply need to be aware of their needs at any particular time in the various seasons. Too much water can make the foliage chlorotic and rot the roots. Too little water will cause the rose to produce few blooms and might even kill your rose in the long run.