Getting the best from container roses.
With the right care, roses thrive in containers and can be the best option in difficult gardens where root competition, shade or restricted watering are an issue. The advantage of containers is that the water goes directly to the roots. Where water is limited, using grey water every day will suffice, as long as the container is flushed with fresh water once a week. The right kind of care means planting the rose in a large enough pot (minimum size 35cm diameter), with good potting soil (not garden soil), watering it daily and feeding it regularly. There needs to be good air movement so don’t place a container directly against a wall, especially a wall that catches hot noonday or afternoon sun.
Use Ludwig’s potting mix (which contains controlled-release Vigolonger) or a commercial potting soil mixed with an organic material like palm peat that conditions the soil and retains water. Do not apply any fertiliser to the newly planted rose – it needs to settle into its new home first.
Roses in pots need to be watered every day in summer and every 2 – 3 days in winter. To aid water retention mix water-absorbent gel or coir (coconut fibre) into the potting soil. If you don’t have the time to water every day, install an automatic or semi-automatic watering system with pipes leading into each pot. If you water by hand use a hose with a fine nozzle as this will prevent the potting soil from becoming compacted.
To keep growth lush fertilise every two weeks by sprinkling a granular fertiliser such as Ludwig’s Vigorosa 5-1-5 (25) over the bushes, at half the recommended rate. (Don’t just put it in a heap next to the stems.)
Spray regularly to prevent black spot and downy mildew. For insect control apply Koinor as a soil drench at the beginning of the season or spray regularly with Ludwig’s Insect Spray. In wet weather spray once a month with Chronos or the combination spray Rose Protector, which is also available in ready-to-use spray bottles.
When to repot?
If the initial potting soil has the right texture the roses can grow in it for many years. Just renew the soil each year after pruning by scooping out as much of the soil as possible and adding fresh potting soil. If the rose starts to lose its vigour it is an indication that you need to repot completely.
Pro tip: If the base of the roses looks bare, fill in with low-growing, shallow-rooted spring and summer annuals like pansies, dianthus, petunias, impatiens and alyssum.