In the early nineteenth century the poet John Keats immortalised autumn as the ‘Season of mists!’. With this seasonal abundance of atmospheric moisture it’s easy to see why this is the time of year for fungal diseases. 


Fungi spread by means of tiny dust-like particles called spores. Spores fly through the air and, if the right type of spore lands on an appropriate plant, the spore may start to germinate and develop a fungus - only if there’s moisture around. Hence autumn mists, dew, and showers play an important role in helping the spread of fungal diseases. 

Here are some of the most common fungal diseases that are found in the garden: 

Powdery mildew 

Named after the powdery coating that spoils new shoots and leaves, powdery mildew affects plants like roses, cucurbits (pumpkin relatives), hydrangeas, azaleas, and apples.  

Yates Natures Way Fungus Spray provides effective control of powdery mildew and is suitable to be applied to vegetables, including tomatoes. For non-edible plants such as roses or sweet peas, Yates Rose Gun Spray Ready to Use is a good choice for treating powdery mildew on roses and other ornamentals. 

Leaf spot 

The most notorious leaf-spotting disease is black spot, the scourge of rose plants. The spores of this disease need to sit on a moist surface for about seven hours before they can germinate, so one of the best ways to prevent its development is to keep the leaves dry. Always water roses in the morning and allow the leaves to dry out through the day. From early spring, spray every two weeks with Yates Rose Gun Spray Ready to Use, alternating with Yates Liquid Copper Fungicide Concentrate. Prune to increase air movement through plants.

Root rot 

Often caused by a disease suffering under the unpronounceable name of phytophthora, this problem moves up from the roots to cause dieback in leaves and stems. It affects plants such as snapdragons, leucadendrons, loquats, passionfruit and many others. There is no current chemical treatment, but poor drainage can exacerbate the problem, so try to avoid growing susceptible plants in heavy or clay soils. Improve drainage by incorporating generous quantities of organic matter like Yates Dynamic Lifter Organic Plant Food and compost. Destroy infected plants.


Rust gets its name from the yellow/orange pustules that appear on the foliage. There are hundreds of different rust diseases and they affect a wide range of plants. Use Yates Rose Gun Spray Ready to Use to treat rust. 


Related products

Yates Nature's Way Fungus Spray

Protects against a very wide range of fungal and bacterial diseases. It is formulated from copper and sulfur, which are naturally occurring compounds.

Yates Rose Gun Spray - Ready to Use

A combination of systemic fungicide and contact insecticide. Kills pests and mites on contact and works from within the plant to control black spot, powdery mildew and rust on roses and ornamentals in the home garden.

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