The rose season is coming to a close. As winter approaches, activity in the garden begins to “wind down.” Activity in the Lowcountry rose garden does not cease with the approach of winter as it does in more northern climates — it just becomes less labor intensive. The rose garden is about to enter a state of semi-dormancy.
The roses will continue to grow, although at a slower pace than during the warm summer and fall, until the first freeze hits followed by several more hard freezes.
Late fall is the time to encourage the formation of hips on your roses. The blooms should be allowed to remain on the plant, removing the petals after the bloom is spent. The formation of hips signals the plant to slow down growth and prepare for semi-dormancy. Cutting a rose has the opposite effect — it signals the plant to produce new growth, which will be soon be frozen as winter approaches.
Diseases and Pests
Disease and pest problems will persist as long as it is relatively warm and active growth continues, probably into late November and early December. It is crucial to continue a routine weekly spray program and to control insect and spider mite infestations.
Plants weakened by disease or pests will not survive the freeze/warm-up cycles in December – February typical of our winters.
Once the colder weather arrives, the weekly spray regimen can safely be downsized to a monthly spray program. In our garden, after the plants are as dormant as they are going to be, we clean the beds to remove old leaves and debris. We spray once or twice with a lime sulfur spray to kill any fungus spores that can overwinter, soaking the plants and the grounds in the beds thoroughly.
Watering requirements diminish during this time of year, but adequate water is still essential to the health of the roses. A dehydrated plant is more likely to be damaged during the winter’s freeze/warm-up cycles than a well-watered, thriving plant.
An application of 0-20-20 or 0-20-0 may be made in late November or early December to harden off the plants and promote root development without encouraging new tender growth above ground.
Do not apply lime or sulfur without first getting a good soil test! Check the pH if your roses are not growing well.
Some of the fertilizing programs result in rather stable pH values, but the effects of variable weather conditions and absorption of fertilizers often bring unexpected results. This summer, we found some of our miniatures not performing to expectations. We ran pH tests and found a very low pH in one bed. By testing the soil around each bush, we were able to apply the right amount of lime to get them growing again.
New beds should be prepared now so they will be ready for new roses next spring. Any organic matter added now will decompose and settle, leaving an enriched soil for the new roses. The recipe of 1/3 sandy loam, 1/3 clay, and 1/3 organic matter is ideal for rose growing.
Lowcountry gardens generally do not need the winter protection that northern gardens do. But some rose varieties are winter tender and may need a little protection when hard freezes are expected. Keep a pile of mulch nearby for the special winter protection of varieties such as: Color Magic, Kardinal, Paradise, Flaming Beauty, Herbie, and others. St. Patrick is reported tender by some, but I have not had any problems with the variety during the winters I have grown it.
After a couple of hard freezes during the winter months, roses may be safely transplanted to other locations.
Miniature rose bushes that have become non-productive and woody from old age may be dug up, divided and replanted as separate bushes.
Some new and exciting varieties are on the market this year. Assess the performance of each rose in your garden now, and plan to replace those that have not met your expectations in the garden or in exhibition.