Gardening

Diseases of the rose bush: control and treatment


The rosebush is surely one of the most beautiful flowering shrubs, but also one of the most susceptible to diseases.

Fragile, perhaps, but not indomitable!

Regular and often natural care can eradicate or prevent many diseases and parasites in the rose bush.

Aphids and rosebush

Aphids are one of the main pests that disrupt the growth and often the flowering of the rose bush.

Here are some solutions to deal with aphids on the rose bush naturally:

The ladybug :

By consuming the larvae of aphids, the ladybug naturally participates in the fight against aphids. This method is used more and more by professionals of green spaces and it is 100% organic.

Nettle manure:

This is a great way to control aphids in a 100% organic way.

Here is how to make your own nettle manure

Soapy water:

Based on black soap or Marseille soap, melted in water and sprayed on the plant, the soap prevents aphids from adhering to the leaves.
150 gr of grated soap and 1 tbsp of oil are melted in 1 liter of water, which are then sprayed on the plants.

Find all our tips for controlling aphids

Rose rust

It is the most common fungus in the rose bush.

It takes the form of orange / rust colored pustules under the leaves giving small yellow-red / brownish halos on the top of the leaf

Effective treatment products often sold against diseases of roses can be used on all plants.

  • It is a fungicide that can be used both preventively and as a cure.
  • As soon as the first signs appear, it is imperative to remove all affected leaves and burn them.
  • Prune your rose bushes well and give them space to let the foliage breathe

Find all our tips for effective rust control

Rose chlorosis

This is one of the major problems affecting the rose bush and which results in leaves of the rose bush turning yellow, resulting from a discoloration of the foliage.

Rose chlorosis is linked to soil, often too poor, heavy and limestone which prevents the shrub from getting the iron it needs from the earth.

the external signs are therefore clearly visible and the treatment fairly easy to implement.

  • Bring a voucher compost at the plantation

Every winter, bury horse manure in the ground. If the disease is there, there are commercially available anti-chlorosis treatments that allow the rose bush to assimilate the iron it needs

Powdery mildew and rose bush

Also called powdery mildew, powdery mildew is a fungus that takes the form of a white felt forming a thin film on the leaves and on the stems.

It develops especially when the climatic conditions are hot and humid

The most favorable months for development are the months of April-May when the temperatures rise and the humidity of March / April is still very present.

It is also found in early fall, when the nights get longer and the humidity stagnates again.

  • Ventilate your roses well to prevent humidity from stagnating.
  • Powdery mildew spreads when the roses are too tightly packed and / or the foliage is not breathing ...
  • Immediately remove affected parts.
  • Burn the leaves and infested parts of the plant.
  • Avoid excessive watering.
  • Optionally spray a fungicide
  • Milk. Mix 1/2 liter of milk with 4.5 liters of water (total 5L) and spray every week until completely gone!

Find our tips for effectively combating powdery mildew

Black spots on rose leaves

When your rose bush shows black spots on its leaves, it is probably because he has black spot disease, Marsonia.

The rose leaves turn yellow and black spots then spots appear all over the foliage.

Like most fungi, heat and humidity help them grow.

  • As soon as the disease appears, remove and eliminate all affected parts
  • The disease can stay from one year to the next if everything does not go away
  • Also clean all your pruning tools (secateurs, branch cutters, etc.) used on your diseased rose bush
  • Do not water the foliage
  • Spray nettle manure or horsetail
  • Also spray Bordeaux mixture as a preventive measure from budding then renew when heat and humidity reappear

Note that there are now varieties of roses resistant to Marsonia.

Video: Gardening Tips: How to Cure Fungus on Roses (October 2020).