Roses are among the most recognisable ornamental plants in the garden, but growing healthy, repeat-flowering bushes takes more than choosing a beautiful variety. They need suitable sunlight, healthy soil, consistent watering, good airflow and timely pruning. In South Africa's summer-rainfall regions, including the Highveld, warm weather and summer showers can encourage strong growth while also creating conditions for fungal diseases.
Deep red roses are especially striking because of the pigments that develop in their petals. Their colour is influenced by genetics, pigment chemistry and environmental conditions. A richly coloured bloom is beautiful to look at, but it is not by itself proof that a plant has ideal soil nutrition or is free from stress.
With a few practical habits, gardeners can encourage healthy foliage, strong stems and repeated flowering while reducing common problems such as black spot, poor growth and premature wilting.
Written by Kutlwano Mokoena
Founder of Evergreen Hideout Agricultural Services (NPO: 2024 / 380375 / 07). Focused on plant health, practical garden management and sustainable growing methods.
Quick Rose Care Summary
Good spacing, morning watering, regular inspection and removal of infected leaves help reduce the risk of black spot and other rose diseases.
Roses need a balanced supply of nutrients. Potassium supports water regulation and general plant function, but excess fertiliser can damage roots and disrupt nutrient balance.
Removing faded flowers from repeat-flowering roses can encourage another flush of blooms and keep the bush looking tidy.
🌹 First Encounter: A Bloom in the School Garden
I first noticed this deep red rose in October 2025, at St Francis Primary School in Soshanguve. I was walking through the school grounds, checking on the vegetable garden beds we had been working on, when I came across the school's flower garden. It was being looked after by one of the school gardeners, a cleaner who also cared for the ornamental plants around the campus.
The rose bush was growing near the edge of the flower garden, and it had produced a beautiful bloom. Its petals were a deep, velvety red, appearing almost black in the shadows. They were densely layered, giving the flower a full, rounded appearance. I stopped to admire it because the colour and shape made it stand out from the surrounding plants.
What I observed: The bloom looked fresh and well formed. I could not see obvious damage on the flower, and there were no visible signs of wilting or pest activity on the bloom itself. It reflected the care being given to the flower garden. I asked the gardener about their routine and was told that they watered deeply once a week, pruned regularly and kept the area free of weeds. They relied on water, compost and regular attention rather than chemical sprays.
🌹 Personal Connection: Roses have always been part of my life. Growing up, my father was a street vendor. He sold flowers on the streets of Pretoria to support our family. I remember watching him leave early in the morning with bundles of roses and returning late at night with empty hands and tired shoulders. He did not just sell flowers; he brought colour and beauty into people's lives, even when we had very little ourselves.
Seeing this deep red rose at St Francis Primary School took me back to those days. To me, a rose is more than a flower. It represents resilience, hard work and the quiet dignity of making a living. My father taught me that flowers have value beyond their appearance. They carry emotion, memory and connection. That lesson has stayed with me in everything I grow.
The encounter stayed with me for three reasons:
- The value of consistent care: The gardener's routine showed how regular watering, pruning and weeding can help maintain an attractive flower garden. Good results do not always require complicated equipment or expensive products.
- The importance of observation: A beautiful flower is worth appreciating, but it is also useful to look at the whole plant. Healthy leaves, strong stems and new growth give a better picture of the rose's condition than petal colour alone.
- Respect for the gardener: I made a point of thanking the school gardener for their work. Their quiet dedication to the flower garden, often overlooked, reminded me that every garden, no matter how small or ornamental, can add beauty and value to a community.
📍 Location: St Francis Primary School, Soshanguve, Pretoria — flower garden
📅 Date: October 2025
🌤️ Conditions: Warm spring morning, with a rose in bloom
🌱 Encounter context: Walking through the school grounds and observing the flower garden maintained by a school gardener
Pruning and Airflow: Keeping Rose Bushes Healthy
Roses benefit from good air circulation, especially in areas that experience summer rain, high humidity or long periods of wet foliage. When a bush becomes overcrowded, leaves can take longer to dry after rain or watering. These conditions can encourage diseases such as black spot.
One useful approach is to maintain an open, balanced shape. Some rose varieties naturally develop a vase-like structure, while others grow differently. The aim is not to force every rose into exactly the same shape, but to remove weak, dead, damaged or crossing stems and prevent the centre from becoming excessively congested.
When pruning:
- Remove dead, damaged or diseased stems with clean, sharp secateurs.
- Cut out weak or crossing growth that rubs against other stems.
- Keep enough space between branches for light and air to reach the foliage.
- Remove fallen leaves and infected plant material from beneath the bush.
- Avoid unnecessary heavy pruning during periods when the plant is under heat or drought stress.
Black spot, caused by the fungus Diplocarpon rosae, is a common rose disease. It produces dark spots on leaves, often followed by yellowing and premature leaf drop. The disease spreads more easily when foliage remains wet for extended periods, particularly when rain or overhead watering splashes spores between leaves.
Watering at the base of the plant, allowing foliage to dry quickly and keeping the area beneath the bush clean can help reduce disease pressure. Good airflow does not guarantee that fungal disease will never occur, but it makes the growing environment less favourable for infection.
Watering and Potassium Nutrition
Roses need a dependable supply of water, particularly during active growth, flowering and hot weather. In the Highveld, summer temperatures can rise quickly, while rainfall may be irregular. A rose growing in well-drained soil still needs enough moisture to support leaves, stems and developing flowers.
Rather than following a rigid watering schedule, check the soil around the root zone. If the upper layer has dried and the soil beneath is beginning to lose moisture, water deeply. The aim is to moisten the root area without leaving the plant sitting in waterlogged soil.
Mulching with suitable organic material can help reduce moisture loss and moderate soil temperature. Keep the mulch slightly away from the main stem to avoid holding excessive moisture against the base of the plant.
Potassium is one of the essential nutrients roses need. It supports water regulation, enzyme activity and several processes involved in healthy growth. However, potassium is not a colour enhancer that can simply be added to make red petals darker. Rose colour is strongly influenced by the variety's genetics and the pigments produced in its petals.
Good nutrition comes from balance. Too little potassium can affect plant growth, but excessive potassium fertiliser can interfere with the uptake of other nutrients. Use a suitable rose fertiliser according to its label, and avoid adding extra nutrients unless there is a reason to believe the plant needs them.
Compost can improve soil structure and contribute organic matter, while a soil test can help identify nutrient shortages or pH problems. Healthy roots and balanced soil conditions are a better foundation for flowering than repeatedly applying individual minerals.
Deadheading and Encouraging More Flowers
Deadheading is the removal of flowers after they have faded. For many repeat-flowering roses, removing spent blooms helps keep the plant tidy and can encourage another flush of flowers. It also prevents the plant from putting energy into developing rose hips and seeds when the gardener would prefer more blooms.
For a vigorous repeat-flowering rose, follow the spent flower stem down to a healthy leaf and an outward-facing bud. Make a clean cut just above the selected bud, leaving enough stem to avoid damaging it. A slight angle can help water run away from the cut surface, although the most important points are using a clean tool and making a neat cut.
The traditional five-leaflet guideline can be useful for some rose types, but it is not a strict rule for every variety. The best pruning point depends on the plant's growth habit, strength and the position of healthy buds.
Not all roses need frequent deadheading. Some varieties produce attractive rose hips, while others naturally shed their faded flowers. If you want to enjoy the hips or grow a variety that flowers only once, leaving some spent blooms in place may be preferable.
After pruning, keep an eye on the new growth. Healthy shoots, good leaf colour and developing buds are useful signs that the plant is responding well. Avoid excessive pruning or fertilising in an attempt to force continuous flowering, as roses also need time to maintain their roots and build strong stems.
Frequently Asked Questions
Q: Why are my red roses turning purple or fading?
A: Rose colour can change with variety, flower age, temperature and light conditions. Some red roses appear darker in cooler conditions and lighter or more purple as the flower matures or experiences heat. If the plant also has poor growth or discoloured leaves, check its watering, soil condition and general health rather than assuming the colour change is caused by a nutrient deficiency.
Q: Can I use greywater on my roses?
A: It depends on the water source and what it contains. Greywater from laundry or cleaning may contain salts, detergents and other substances that can build up in soil or affect plants. Avoid water containing bleach, disinfectants, strong cleaning chemicals or unsuitable laundry products. If greywater is used, follow local guidance, use only suitable products and do not apply it directly to edible parts of plants. Fresh water is generally the safer choice for regular rose irrigation.
Q: How often should I water roses in summer?
A: There is no single schedule that suits every garden. Soil type, rainfall, temperature, plant size and whether the rose is growing in a pot all affect its water needs. Check the soil around the roots and water deeply when it begins to dry. Container-grown roses usually need more frequent checks than roses planted in the ground.
Q: How can I reduce black spot on my roses?
A: Improve airflow through the bush, water at soil level where possible and avoid leaving foliage wet overnight. Remove infected fallen leaves and badly affected plant material. Choose varieties with good disease resistance when planting new roses. These practices help reduce disease pressure, although they cannot guarantee that black spot will never appear.
Q: Does every rose need to be pruned into a vase shape?
A: No. Different rose groups have different growth habits and pruning requirements. The goal is to remove unhealthy or overcrowded growth and maintain a shape that suits the variety. Some roses benefit from an open centre, while others naturally grow as shrubs or climbers.
Conclusion: Beauty Grows Through Consistent Care
A beautiful rose is not simply the result of a striking variety. Healthy growth depends on the everyday work of watering, feeding, pruning, observing and responding to the conditions around the plant. In the Highveld, where warm weather and summer rain can bring both vigorous growth and disease pressure, these small habits make a real difference.
The deep red rose at St Francis Primary School reminded me that a well-kept garden does not always need expensive products or complicated methods. Sometimes it comes down to someone taking the time to water, prune, remove weeds and care for the plants consistently.
It also reminded me of my father and the roses he sold in Pretoria. Flowers carry memories, hard work and meaning beyond their appearance. Whether grown for a school garden, a home landscape or a commercial flower business, roses deserve the same thoughtful attention that makes any garden thrive.