By Jennifer Pelham, UF/IFAS Osceola County Extension
Success with roses in the Florida landscape is not as difficult as it sounds. Believe it or not, you can grow beautiful roses with minimal effort. The key to success is the variety of roses you select. Old-garden roses and Knock-out® roses have proven to take the harsh Florida weather and thrive in almost every landscape. These roses are low maintenance and will retain most of their foliage and bloom throughout the year.
In Florida, most of us think roses are high-maintenance plants, with success only obtained when the plants are cared for properly. Many believe they require heavy grooming, routine fertilizer and weekly applications of fungicide to control the leaf disease. This is all true – for hybrid roses. However, it is not true for old-garden and Knock-out® roses and other cultivar of roses that are grafted on the ‘Fortuniana’ rootstock. Research has shown that roses grafted on ‘Fortuniana’ rootstock are more vigorous growers, produce more flowers, and live much longer in Florida than roses grafted on other rootstocks.
There are many varieties of roses on the ‘Fortuniana” rootstock to choose from. It all depends on your preference for flower color, fragrance, and shape. Roses prefer to be planted in direct sunlight for a minimum of six hours per day. They also like moist, but well-drained soils. Most soils in central Florida are sandy. Sandy soils do not hold much moisture; therefore, they should be amended with organic material.
Adding organic material such as compost, manure, or peat will increase the water and nutrient holding abilities of the soil. Soil amendments should be added to the entire planting bed not just to the planting hole. This is because the roots of the rose bush will grow quickly beyond the initial planting hole and will benefit from amendments. To amend the soil, add 2-4 inches of organic material and mix evenly to a depth of 12 inches.
Properly plant the rose bush by digging a hole as deep as the root ball or slightly shallower. Before placing the plant in the hole, loosen its circling roots. Be careful not to plant the rose too deep. Fill the hole with soil and apply a 3 inch layer of mulch (wood chips, bark, or pine needles) around each plant. Make sure to keep the mulch an inch or so away from the base of the stem. Irrigate frequently for 6-8 weeks to establish.
If you have established roses in your landscape, now is the time to prune them. Heavy pruning should take place in early spring. This includes shortening the main stems. Leave at least half the length of each main cane that is one to three years old. Also, remove branches that are dead, diseased, damaged, or spindly. This improves the overall form of the rose, controls the height and improves air circulation and light penetration within the plant.
For proper health, the roses should also be fertilized routinely. Select a fertilizer formulated for roses, preferably one containing micronutrients and slow-release or controlled-release nitrogen. Roses should be fertilized once a month from mid-February to mid-November in central Florida. Apply one cup of fertilizer per plant per application or ½ cup bi-monthly. Reduce this amount and frequency for smaller plants.