LSU AgCenter Horticulturist
If you’ve been keeping up with your roses, you took care of fertilizing and trimming them in late summer during August or, at the latest, September. Undoubtedly, your repeat-blooming roses like Knockout and Louisiana Super Plant drift roses are looking gorgeous right now. They put on quite a display each fall.
Roses come in many colors, shapes and sizes. From ever-blooming roses to trailing roses to highly fragrant hybrid tea roses and those prized for their large beautiful flower heads, there is a type of rose for anyone.
With this last push of colorful blooms during fall, it’s time to stop and smell the roses. At this point, there is not much more that you should be doing with roses other than preparing them for winter.
Go ahead and put away the pruners and fertilizer. As the danger of the first frost or freeze approaches, it is not a good practice to prune or fertilize roses. New tender flushes of growth stimulated by pruning or fertilizer will by susceptible to severe damage from cold weather.
Although roses are winter-hardy in Louisiana, you can do a few things to ensure they stay healthy and that you have the most productive and beautiful flush of blooms in early spring. Roses will not go into complete dormancy in our USDA hardiness zones, and our low temperatures usually do not require freeze protection. However, your rose shrubs can still benefit from applying 2 to 4 inches of mulch to help protect the crowns of the plants.
Mulch not only helps retain moisture, but it also helps reduce weeds in garden beds and insulate the soil to keep it warm during the colder winter months. The fall is our driest time of year; be sure to water shrubs in extended periods of drought.
Fall is a good time to be proactive against insect pests and fungal diseases. Apply a dormant oil to kill any insect pests. You can also continue with your fungal spray regimen. Copper fungicides work well and can be applied to control black spot, downy and powdery mildews on roses.
Another good practice is to rake any leaves that may fall after freezing weather in the winter. This will help prevent the further spread of fungal diseases in the future.
In late winter, at the end of January and early February you can resume rose care practices such as pruning. Remove diseased canes and those that are weak. Additionally, you can trim back those gangly, lanky branches you’ve been aching to clean up. Cut branches you intend to remove completely at the base of the plant.
Trim the entire shrub back by one-third to one-half. This will encourage a new flush of foliage for spring. Water roses at the base of the plant to prevent getting water on the foliage. This will help reduce fungal disease.
What you can do this time of year is plant roses. In fact, the cooler weather makes it so much nicer to perform the more vigorous task of digging and planting. Although many nurseries are gearing up for Christmas trees, many still carry a nice selection of roses. Newly planted roses should be fertilized only with phosphorus to encourage new root growth and development. This will help plants establish during the winter months.
Be sure to water newly planted shrubs in well, avoiding water on the foliage as usual to help prevent fungal disease. You can fertilize roses in early spring when new leaves begin to emerge. Use a fertilizer with ratios such as 5-10-5, 4-8-4 or 4-12-4 as a maintenance fertilizer for roses. Spread the fertilizer evenly around the roses and lightly work it into the soil. Gently water fertilizer in.
Roses are a true delight, bringing joy and beauty to our homes and gardens. With so many cultivars, it is one of the most highly cultivated flowering shrubs in the world.
For now, just sit back and enjoy the fall rose show.
Roses put on a beautiful display each fall in Louisiana. Photo by Olivia McClure/LSU AgCenter
Although roses are winter-hardy in Louisiana, you can do a few things to ensure they stay healthy during the upcoming winter. Photo by Olivia McClure/LSU AgCenter
Some rose bushes may look spindly this time of year, but it’s best to leave them alone as cold weather approaches. Wait until late winter to prune. Photo by Olivia McClure/LSU AgCenter
Pollinators like this bee enjoy roses. Photo by Olivia McClure/LSU AgCenter