Le Clos by Dr. Chris Robichaux

Roses are one of our most popular ornamental plants. And home gardeners should learn about and be aware of recommended management practices for roses.

Roses come in many types, but basic care is the same for most. Keys to success with roses include correct sunlight conditions, ideal soil pH, proper pruning, regular fertilization, proper mulching, disease management and insect control.

Roses need full sun in order to perform the best, grow the best and bloom the best. This means eight hours or more of direct sun daily. Less than eight hours is not sufficient for ideal performance. Many of us underestimate the amount of sun that our landscape receives.

Soil pH is important. Ideally, soil pH should be in the 6.5 range. This is considered slightly acid. Do not guess on soil pH – soil test. You can lower soil pH with sulfur products and raise it with lime products. But always do this based on the results of a soil test.

What about pruning? Mid-February is the time to prune most rose varieties. They should also be pruned in early September. Heavy pruning is done in February with light pruning in late summer. Hybrid tea roses need to be pruned more heavily then floribunda, grandiflora and landscape shrubs roses.

Fertilization is very important. This is especially true if you don’t follow some of the other management practices and care considerations more carefully.

To maximize spring growth and first flowering in April, fertilize roses in late winter to early spring. Use a slow-release fertilizer. You can also fertilize again lightly in early summer and again after late-summer pruning.

Mulch roses with 2 to 3 inches of pine straw. You can use other mulches, but pine straw seems to be best. Refresh the mulch layer as needed. Mulch suppresses weeds, minimizes soil temperature fluctuations and conserves soil moisture.

Disease and insect management is important when growing roses.

You should follow a preventive fungicide application program to control blackspot fungus on hybrid tea, floribunda and grandiflora roses. Usually landscape shrub roses, like the Knock Out variety, do not need fungicide applications. It is important to control blackspot in spring. If the disease gets started, it is very hard to get under control later in the year.

Major insects affecting roses are thrips and aphids.

To minimize care needed in the rose garden, plant low-maintenance roses like the Knock Out varieties – the double red and double pink flower forms are especially nice. Also try the Louisiana Super Plant, smaller-growing Drift roses. These are 2- to 3-foot-tall plants and come in a variety of colors.

We should consider old garden roses for more use in Louisiana. And we also should include Earth Kind rose varieties in any home landscape planting featuring roses. Some of the favorite Earth Kind varieties include Belinda’s Dream and Duchesse de Brabant.

Picking the right varieties and following these recommended practices will help your roses be successful long-term in the landscape.

For more information, contact Dr. Chris Robichaux, county agent/area horticulturist, St. Martin/Iberia parishes, at 332-2181 or 369-4440.