While most rose bushes love the sun, the intense afternoon heat can be a major stressor for them, especially when bud and bloom rose bushes (those growing, budded, or blooming in their nursery pots) are planted during the hotter period of the growing season. Keeping roses healthy during hot weather is important to having beautiful roses.
Protecting Roses from Hot Weather
When the temps are in the mid to high 90s to 100s (32-37 C.) and up, it is important to try and keep them not only well hydrated/watered but also to provide them some form of heat relief. When the foliage looks wilted, it is a form of natural protection that will usually come out of it during cooler times of the evening. In places such as Tucson, Arizona, where there is little time for such “relief breaks” from the intense heat, it is important to try to create a means for such “relief breaks.”
Relief breaks can be provided for your rose bushes by creating shade during those hottest times of the day. If you only have a few rose bushes, this can be done by using umbrellas. Buy some umbrellas that are made from as light colored a fabric. Reflective silver or white is best though.
If you can only find darker-colored umbrellas, you can turn them into shade-making, sun-reflecting palm trees of sorts! Just cover the umbrella of any color with aluminum foil with the shiny side up or cover the umbrella with a white fabric. Use Liquid Stitch or another such sewing compound to attach the white fabric to the umbrella(s). This will help them to reflect the sun’s intense rays and improve the quality of the heat-relieving shade. Silicone caulking works well to adhere the aluminum foil to the umbrella(s) if aluminum foil is used.
Once we have the umbrellas ready to go, take some ½ inch (1 cm.) diameter, or bigger if you like, wood doweling and attach the doweling to the handle of the umbrella. This will give the umbrella enough height to clear the rose bush and create the palm tree effect of shade for the rose bushes concerned. I use a long enough piece of doweling to get 8 to 10 inches (20.5-25.5 cm.) of it into the ground to help it stay put in light winds. The doweling may not be needed for other plants that need some relief, as just the handle of the umbrella can be stuck in the ground. The shading will help give the rose bushes and plants the relief break needed and the light color of the umbrella covering will help reflect the sun’s rays, thus helping to reduce any further heat build-up.
There are other ways to create the same type of relief shading; however, this information should give you an idea of what can be done to help those rose bushes that are struggling with the intense heat.
Again, be sure to keep them watered well but not soaked. During days when things cool off, wash down the foliage well when watering the roses, as they will enjoy it.
Many rose bushes will stop blooming when under heat stress, as they are working hard to keep the needed moisture flowing to their foliage. Again, it is a natural form of protection for them. The blooms will return when the weather goes into a cooler cycle again. I have used the umbrella shade method myself and have found them to work extremely well.