Common rose problems and diseases to look out for and possible solutions

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Common rose problems and diseases to look out for and possible solutions

Common rose problems and diseases to look out for and possible solutions

Last Updated on June 19, 2020 by John

Roses are very popular grown, and gardens and formal rose borders all over the UK. Unfortunately, some varieties are particularly prone to rose problems, especially diseases such as Black spot, mildew and rust. That said it’s important to know what the common problems are so you can look out for them, their symptoms, and any possible solutions to help prevent them and combat them.

Rose leaf problems

Powdery mildew on rose bush

Powdery mildew

There are situations where the leaves develop a powdery, white growth. This is the manifestation of a fungal disease called powdery mildew. While you might notice it on the leaves, it can also impact the stems, the flower buds, even the flowers. This is often the result of over-watering or wet conditions and should be treated immediately.

We recommend removing effected leaves and spraying with a fungicide.

Rose Black Spot causes

Black Spot

If your leaves have dark spots and leaves are falling off, this is Rose black spot . Black spot is a common fungal disease which is quite damaging. It usually manifests in black or purple spots that get bigger with time eventually lined with a yellow perimeter. If left untreated, it will spread to the other leaves, causing them all to die back and fall off. You can treat this with a Fungicide and remove any damaged leaves or stems to prevent the spread.

Learn how to treat black spot in this guide by clicking here.

Rust

Rust fungus on rose bush leaves

If you notice small yellow spots on your leaves with orange pustules as pictured above, this is Rose rust. This is also a fungal infection, but with this, the fungus produces the orange Spore pustules throughout the summer. If left untreated, these orange pustules will be replaced by black pustules later in the season. Again the treatment is to spray with a fungicide and the prevention by way of removing any damaged parts of the plant. Be careful too, when removing damaged parts because you don’t want to accidentally spread more of the fungus by rupturing the pustules.

Sawfly

Sawfly on roses which strip leaves off stems

When the leaves start to roll downward into the shape of a tube, the culprit is a pest called the sawfly. This needs to be treated immediately as the larvae of the sawfly will eventually eat the plants and can strip roses down to bare stems very quickly.

This needs to be treated by spraying with a pesticide such as RoseClear.

Leaves turning yellow and falling off – read our guide now

Recommended fungicides to treat most problems

Sale
Scotts Roseclear Ultra Gun, 1L
  • Systemic insecticide and fungicide with 3-in-1 action
  • Kills systemically and on contact
  • Kills aphids
  • Controls blackspot, powdery mildew and rust
  • Protects for up to 21 days to prevent further attacks
FungusClear Ultra 225ml
  • Systemic protection and control of blackspot, powdery mildew and rust
  • Use on roses and other flowering or ornamental plants
  • Protects new growth and protects plants for over 3 months, when used at intervals recommended in usage instructions
  • Use between March to September
  • Apply using a garden pressure sprayer washed before and after use
Sale
Provanto 86600250 Fungus Fighter Plus, Fungicide Protects For 3 Weeks, 1L, Ready-To-Use
  • Controls box blight
  • Controls blackspot, mildew, rust and leaf spot on roses and other ornamental plants and selected vegetables

Aphids leading to honeydew

Aphids on rose bush leaves

When the leaves have become sticky and shiny with black growth on top, you have a problem that needs to be treated two-fold. Firstly, this is indicative of an aphid infestation, usually, greenfly or blackfly, and the aphid infestation needs to be treated with an insecticide (bug killer). The sticky deposit that’s left behind is honeydew, but the black growth you might see on top of the leaves is mould. All of the affected leaves should be properly remove and discard so that they don’t spread the mould throughout the rose bush.

Sale
RoseClear Ultra Concentrate 200ml
See availability from the best retailers

Leaf-cutter bees

If you notice oval pieces or very neat semi-circles removed from the edges of your rose bush, this is a sign of leaf-cutter bees. The females will cut away the small pieces to make their nests. Rest assured this is the only pest problem for which no control is necessary, as these cuts do not damage the plant in any significant fashion.

Flower problems

rose flower problems

Rose blindness

The rose flowers themselves can succumb to problems the same as any other part of the bush. If you notice that most of your shoots have failed to produce flowers, it’s often the result of Rose blindness.

If you are dealing with rose blindness, the best treatment is to cut back the blind stems by half, give your plants adequate fertilizer to stimulate more growth, and wait for the next season.

Sale
Rose Care Toprose Rose and Shrub Feed, 4 kg
  • Ideal balance of nutrients for roses and shrubs
  • Easy to apply: Simply sprinkle around your roses and lightly hoe into top soil
  • Contains long-lasting nitrogen for balanced growth
  • Also contains iron and magnesium that guard against premature leaf drop
  • Toprose is a boosted granular plant food for high results

Flower balling

If you have a double-flowered variety, but many of your flowers are turning brown and never opening all the way, it’s the result of flower balling. Flower balling is often caused by cold, wet weather and there is not really a solution to this but wait for better weather.]

Proliferation

Finally, if your plant is producing unopened flower buds inside of your original flower petals, this is a problem called proliferation. One of the most common causes is physical damage to the developing flower bud but if you plant continues to show this symptom instead of doing it once or twice it might be a virus infection in which case you will have to remove the entire plant.

Root Problems

Root decay is one of the biggest problems you will find in the root system of your rose bush. If you dig down to the roots and you notice that they are soft and brown, that’s the result of root decay often caused by a disease.

Honey fungus & Phytophthora root rot

One of the most common diseases is that of honey fungus, which is particularly problematic for plants that are grown in the ground. Phytophthora root rot is problematic for bushes grown in containers.

Waterlogged sites leading to root rot

Most roses are suitable for clay soil. However, if the roses are left sitting in standing water for too long, they get waterlogged, which causes root rot. Any drainage problems you might have in the containers can contribute to this problem. 

Improve drainage

The best way to resolve this issue is to make sure the soil is free draining by digging organic matter and grit into the soil to improve drainage and if growing in containers making sure the drainage holes are sufficient and you have crockery over the holes so they do not become clogged up.

Rose bush growing in container

Damage roots caused by hard frost

If you are growing in a container, a hard frost can also cause damage to the roots. To help thwart this you can wrap your containers in bubble wrap or Horticultural fleece when the weather is scheduled to get a little frosty.

Rose Sickness

If you recently planted new roses directly into the ground where other roses have previously been cultivated, and now the roots are not growing, it could be a problem called Rose sickness or replant disorder. When gardeners replant old roses with new roses, sometimes the new roses don’t thrive because they never quite get established. In more severe cases the new roses die back.

We recommend adding plenty of organic matter and farm manure to the soil and mixing in well to add vital nutrients back into the soil.

Stems and branch problems

Rose diseases on stem

Some problems are more visible than others. If the branches on your roses are starting to die off, a fairly common occurrence, there are a handful of causes.

Stem dieback

Firstly, this dieback could be a symptom or manifestation of root rot, as mentioned above. When the plant can’t take up water through its root structure, everything suffers, including the stems and branches.

Grey mould and Rose canker

In other cases, the dying branches could be a result of a fungal pathogen on the branches exclusively. Gray mold and Rose canker are quick to colonize on any rose branches that are not already strong. They target branches that have been damaged by pests, nutrient deficiencies, or have been physically damaged by poor pruning or cold weather. In fact, all of these potentially harmful conditions can cause dieback on their own, but it’s usually the manifestation of pathogens on those branches that make the problem severe.

To help prevent this ensure you spray aphids and pests with a pesticide at the first signs, prune roses correctly at the right time of year following our guide and ensure you deal with any nutrient deficiencies by improving the soil.

Scale insects that attack citrus including lemons

Scale insects

If your stems or branches are covered in small brown structures, you have scale insects. Scale insects are one of the most common insects to affect rose bushes along with greenfly. They’re flat, circular and you will see them visibly on the stems or branches. You can treat these with pesticides or by giving the plant a thorough wash.

Sale
Scotts Roseclear Ultra Gun, 1L
  • Systemic insecticide and fungicide with 3-in-1 action
  • Kills systemically and on contact
  • Kills aphids
  • Controls blackspot, powdery mildew and rust
  • Protects for up to 21 days to prevent further attacks

Crown gall

Some plants start to develop large swellings near the base of the stem. This is the sign of a bacterial disease referred to as Crown gall. While the first sign you notice will likely be at the stem of the base, the roots can be impacted by this disease as well so getting a commercial treatment to quickly and swiftly handle the problem is best.

Suckers from the base of rose

Suckers will develop below ground level with leaves that look slightly different than the rest of the plant. If your roots are injured suckers can develop, so it’s essential that to prevent suckers, you avoid damaging the root structure when you are digging or hoeing. If you do notice suckers on a grafted rose, you can dig down to the point of origin within the root structure and pull it away. Most people make the mistake of removing a sucker at soil level but, without removing it at the root level, it will simply regrow.

With so many types of diseases, pests, and environmental issues that can affect your plant it’s good to know how to identify the signs of problems for each part of your rose bush and subsequently how to treat or control it.

With this information, you will be able to cultivate a stunning rose garden, tackling any issues as they arise.

Last update on 2020-10-20 at 03:52 / Affiliate links / Images from Amazon Product Advertising API

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