black spot
Black spot is a fungal disease causing black/purple spots on leaves, a loss of vigour, leaf loss and leaf yellowing.
Make sure to prune roses annually and collect any dead leaves below the plant, as well as remove any affected leaves or stems. Disinfect secateurs between plants when pruning to reduce the transfer of spores.
dieback
Dieback is exactly as it sounds – the browning dieback of stems and shoots on the rose. It can be down to poor pruning, where the stub of a stem suffers dieback, or from stress, such as underwatering or waterlogged soil, or frost damage.
Prune any stems affected by dieback as soon as you notice them. To help prevent dieback make sure any old or damaged stems are removed when pruning.
flower balling
Also known as bloom balling, this is a problem that can occur in periods of wet weather followed by sunshine. Flower heads fail to fully open and turn brown and soft – this is because the petals have become stuck or ‘balled’ together after becoming wet or damp and then being dried by the sun.
Remove these failed flowers as soon as you see them. Good air circulation around the plant helps (don’t crowd roses when planting).
rose rust
Rose rust is another fungal disease brought on by warm, damp conditions and it shows up as bright orange and then black pustules on the underside of the leaf.
If you notice it early enough you can remove the affected leaves and dispose of them (but not on the compost heap). If the plant is severely affected with lots of die back, it may be too late to save the rose and it will need to be dug up and disposed of.
The spores can lie dormant on dead leaves, so collect any leaves below the plant, as well as remove any affected leaves.
rose replant disease
Replant disease occurs when you replace a rose in soil where another rose was previously grown. The new rose can fail to establish or put on growth and the roots may rot.
To reduce the risk of this you can swap the soil for fresh soil (by digging it out and replacing it) from elsewhere in your garden. Using mycorrhizal fungi is also thought to help.
powdery mildew
This is a fungal disease that shows up as a powdery coating on the foliage, starting with the young rose leaves before spreading to older leaves and then the flowers.
You can remove any affected leaves and try an organic solution such as homemade comfrey tonic to keep mildew at bay.
The best way to avoid powdery mildew in the first place is to ensure good air circulation around the roses, a good watering regime and a preventative spray of comfrey tonic.
aphids
Aphids, also known as greenfly or blackfly, can be found on a range of plants, including roses. They cluster on shoot tips and new buds, and suck the sap of the plant, leading to a loss of vigour and distorted growth. You may also spot ants, which protect the aphids and deter their predators.
A solution of a drop of washing up liquid in water in a spray bottle can help with minor infestations. And you can also encourage predators, such as birds and ladybirds, to the garden to help control aphids. You can also wipe them off using your fingers.
how to get rid of greenfly on roses?
Aphids can be a common problem for roses and you can see them clustered on flower buds or young growth. You can clean them off using your fingers to keep the numbers down. A garden with diverse insects should help too, as ladybirds love to feast on them.
why do roses droop and wilt?
Roses thrive in a sunny position with regular watering. Drought or waterlogged soil can cause roses to wilt.
why have my roses stopped blooming?
Many roses are not repeat-flowering – most ramblers, for example, flower just once. A rose in a shade will also struggle to flower.
why are my roses turning yellow?
It could be that it’s not getting enough sun or is affected by black spot. If there is no evidence of fungal disease or pest attack then there may be a lack of nutrients in the soil – use rose tonic to improve the situation.
why are my roses losing their leaves?
This could be due to fungal diseases. But roses are mostly deciduous and will lose their leaves in winter.