Camellia leaf blight

Camellia leaf blight is a disease that can be caused by two fungal pathogens: Monochaetia karstenii or Pestalotiopsis species. The development of the disease is favoured by wetness on the leaves and any factors that weaken or damage the foliage.

You may see the following symptoms:

• Discoloured patches develop on the leaves. These soon turn brown, giving the lesions a scorched appearance
• Numerous tiny, black fruiting bodies of the causal fungus develop over the surface of the lesion (damaged area). In wet or very humid conditions these may be seen to exude a black tendril of spores
• Infected leaves often fall prematurely. The infection can spread down the petiole
  The stalk that attaches a leaf to a stem or branch of a plant. It allows the leaf to be positioned to receive the maximum amount of sunlight for photosynthesis. and into the branch, leading to dieback. Affected cuttings
  A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year. may decay completely

N.B. Camellia leaves may also develop brown patches as a result of frost damage in spring, or sun scorch during hot summers. In these cases the symptoms will often develop quite rapidly on several leaves at the same time, and fungal fruiting bodies won't be visible. See our advice profile on camellia problems for further details and photos.

The RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar

Gardeners often use the word variety when referring to a specific plant, but the correct botanical term is 'cultivar'. Whichever word you use, it means a distinctive plant or plants, given a specific cultivar name and usually bred to enhance certain characteristics, such as flower or fruit size, colour, flavour or fragrance, plant size, hardiness, disease resistance, etc. Additionally, it is worth knowing that, botanically, variety has another meaning - it refers to a naturally-occurring distinct plant that only has slight differences in its looks. For example, Malva alcea var. fastigiata differs from typical plants by having an upright habit. selection, garden hygiene

Regular cleaning and tidying not only keeps a garden looking neat, but can reduce pests and diseases too. Beneficial jobs include collecting fallen leaves, promptly removing diseased growth and debris, cleaning tools, and weeding. Still, too much tidying can discourage wildlife, so it’s a fine balance. and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner.

Non-chemical control

• Good hygiene can help, as do cultural control measures. These include removing affected leaves, twigs or cuttings
  A method of growing new plants from parts of an existing plant, such as sections of root, stem, leaf or bud. When prepared correctly and planted in the right conditions, they can produce roots and eventually become independent plants. There is a wide range of different methods for taking cuttings, depending on the plant and time of year. promptly and destroying them. Where possible, keep leaves dry to prevent dispersal and germination
  Germination is the process by which a seed develops into a new plant. It starts with the seed coat absorbing water, expanding and splitting, which allows oxygen and water into the seed so its food reserves can be broken down and used by the embryo for growth. The first root (called the radicle) pushes into the soil to anchor the new plant in place and start absorbing water and nutrients. The first shoot (called the plumule) then grows upwards, out of the soil, towards the light. of the spores
• If pruning out affected twigs or branches, disinfect the pruning implement between each cut

Fungicides

The RHS recommends that you don't use fungicides. Fungicides (including organic types) may reduce biodiversity

The variety of living organisms (plants, animals, fungi and microorganisms) in a particular environment. Boosting the biodiversity of your garden has many benefits, including supporting wildlife, improving soil health and reducing the likelihood of pest and disease problems. , impact soil health and have wider adverse environmental effects. If you do intend to use a fungicide, please read the information given in the link and download below to ensure that use, storage and disposal of the product is done in a responsible and legally compliant manner.

The products listed in the ‘Fungicides for gardeners’ document below are legally available for use by home gardeners in the UK. This information is provided to avoid misuse of legal products and the use of unauthorised and untested products, which potentially has more serious consequences for the environment and wildlife than when products are used legally. Homemade products are not recommended as they are unregulated and usually untested.

There is no information available on the efficacy of any home garden fungicide against camellia leaf blight.

Download

Fungicides for gardeners (Adobe Acrobat pdf document outlining fungicides available to gardeners)

Link

Chemicals: storing and disposing safely

Large numbers of spores are produced by the fruiting bodies. The spores are spread by water splash, and will germinate to create new infections if the leaf surfaces stay wet.

The fungi are generally regarded as weak pathogens, and are much more likely to colonise plant tissue that is damaged, dead or that has been weakened by stress factors.