The rose-growing mistakes that could be killing your flowers

Fix these three rose-growing mistakes and fall in love with your flowers all over again

If you have roses in your garden, no doubt you’ll already know how fussy they can be. But if you’ve been really struggling to keep your flowers happy, the solution might be simpler than you think. We’ve spoken to garden experts who have revealed three major (yet common) rose-growing mistakes many of us are making. 

Roses’ regal beauty and unmatched elegance is fragile, and sometimes it can feel like a balancing act to keep them thriving. From managing pest control to nourishing your plants, sometimes it’s tough to know the right way to look after roses.

Pink roses growing in gardenCredit: Serhii Brovko/Shutterstock

If you’re guilty of making any of the three following errors, then here’s where your fraught relationship with rose growing ends. Get ready to fall in love with these flowers all over again.

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1. Giving them the wrong companions

Some plants are toxic to roses

You may want to think about what other plants you have close by to give your roses a better chance of thriving. For example, it’s a bad idea to plant them with anything that attracts aphids, such as salad plants (lettuce and arugula) as these will spread to your roses.  

Other no-nos are plants that grow aggressively, such as ferns and bamboo, as these will compete for nutrients – not good given that, according to David Austin Roses,Roses are greedy feeders and do not like too much root competition. You should also avoid planting roses near any members of the nightshade family, such as tomatoes, potatoes or peppers, as they can produce toxins that are harmful to roses.

Salvia nemorosa with pale pink rosesCredit: Klever ok/Shutterstock
Salvia nemorosa works to keep black spot away from these pale pink roses.

So what are good companions for roses? “Plant them with the compact salvias, such as S. ’Nachtvlinder’ and other jamensis or gregii hybrids, which helps hugely in keeping them blackspot and mildew-free,” says garden expert Sarah Raven, who notes that salvias make great companion plants for roses.  

Why? Salvias release a natural fungicide that helps keep blackspot at bay, and they can encourage beneficial insects to the area, some of which can help control pests, like aphids – protecting roses in the long run.

2. Not being proactive in tackling pests and disease

Remain vigilant: observe, identify early and treat

Fungal rose disease Black SpotCredit: Piaffe Photography/Shutterstock
Hybrid tea, patio and climbing roses are particularly susceptible to black spot.

Sometimes, through no fault of our own, we don’t pay roses quite enough attention. 

 “What you don’t want to do is ignore the garden,” says Guy Barter, chief horticulturist of the Royal Horticultural Society.  Doing so might mean you end up finding lots to deal with, not to mention, scrap plants.  

 “Vigilance is the main thing, where you might want to order some biological controllers which are little insects you buy to control unwelcome visitors.” 

Robert Silver, founder and CEO of ProGardeningBlog, highlights how not addressing issues immediately can cause problems later down the line. “Most gardeners make the common mistake of forgetting to protect their roses with appropriate insect and disease management treatments.  

“Neglecting these problems could be harmful to the plants. Aphids, mites, and several diseases, including powdery mildew and black spot, can all affect roses. The roses may suffer significant harm, including defoliation, stunted development, and even death if these issues are not swiftly resolved.   

“Maintaining the well-being and vitality of roses requires regular observation, early identification, and proper treatment techniques such as organic sprays or methods for integrated pest management.”  

When treating roses, try to use organic remedies where you can, but always look to be proactive. 

What are the symptoms of common rose problems?

The RHS explains on its website that rose aphids are a common problem and shares some key symptoms to look out for. 

  • Check flower buds, shoot tips and young foliage for clusters of pink or green insects 
  • Infested flower buds and leaves may contain empty, white cast aphid skins on them (this is because aphids moult their old skins). 
  • Aphids excrete a sticky honeydew that can cover flower buds and foliage. 
  • A black, sooty mould might be growing on this honeydew. It will look like brown-black powder on upper leaf surfaces.

Spider mites can infest roses, particularly liking the warm and airless conditions of greenhouses and conservatories, according to Harkness Roses. In gardens, they might appear because the use of insecticides has killed their predators, the company says. 

  • Your roses may look like they’re covered in fine spiderwebs, which protects the mites’ and their eggs. 
  • Leaves will likely discolour and turn limp and pale before falling, Harkness Roses says.

This common issue is caused by a fungus and can affect all areas of the plant above the soil. 

  • Signs include the powdery white fungus growing on the leaves (all surfaces can be affected) and shoots, the RHS says. Mildew may also be found on all other parts of the aerial plant (stems, flowers etc) and will be thicker on the stems surrounding the thorns; this growth will brown with age. 
  • Affected leaves may discolour to yellow, red or purple. Very infected leaves may curl and distort. 
  • Some flower buds may not open properly if they’re very infected. 

Another fungal disease affecting roses is blackspot. It’s a serious threat to these plants – so much so that many growers breed resistance into certain strains of the disease. Sadly though, new strains emerge all the time, so gardeners must remain vigilant.  

  • Look at the leaves, which will develop purple-black patches that get bigger. 
  • Affected leaves will likely drop off the plant and may even turn yellow around the spots – so be sure to look at the ground around each plant too. 
  • The RHS says sometimes leaves will drop without any yellowing, but still with spots. 
  • Carefully inspect leaves on the plant for smaller spots; these leaves may not be affected enough to drop but are still diseased.  
  • Small, black scabby lesions may also appear on young stems, according to the RHS. 

3. Not giving them sufficient nutrition, at the right time

Fertilisation can boost growth, foliage and flowers

Gentle Hermione David Austin RosesCredit: David Austin Roses
These Gentle Hermione roses by David Austin Roses have a strong myrrh fragrance.

“One common mistake is not providing sufficient nutrients to roses through fertilisation,” says Silver. “Insufficient nutrient supply can lead to weak growth, pale foliage, and reduced flowering. It is essential to choose a suitable rose fertiliser and apply it at the right time and in the recommended quantities.”  

Ensuring roses enjoy all the necessary elements they need will give more vibrant blooms and a healthier rose will also be better protected to fight off disease and withstand environmental stressors throughout the seasons. Silver notes how applying fertiliser too early in the season may lead to excessive foliage growth, inhibiting flower growth in the process.  

“On the other hand, late fertilisation can prevent roses from properly hardening off before winter, making them more susceptible to frost damage,” he warns. Be sure to check the instructions for your variety of rose. “It is important to follow the recommended schedule and fertilise roses during their active growth periods for optimal results” adds Silver. 

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Camille Dubuis-Welch

Written by Camille Dubuis-Welch she/her

Updated:

Camille is a freelance writer based in north London with her cat and two friends. Cam has been in love with everything interior design and garden-related since before she can remember and is the former deputy editor of realhomes.com, where she got to collaborate with some very inspiring DIYers and focus on small-space improvements.