Five Most Wanted

Any gardener looks forward to the promise of beautiful flowers and shapely lawns, but all too often these can be spoilt by diseases, fungal or infectious. So we’ve prepared a ‘most wanted’ roster of some of the most commonly occurring, and also of the fastest degrading afflictions that can affect your ecosystem.

Having read this and next week’s article, you’ll be able to identify and (hopefully) treat these ailments before they’ve a chance to permanently damage your plants.

picture of powdery mildew

Powdery Mildew

Powdery Mildew is a fungal affliction which can affect a myriad of garden-variety plants including vegetables and flowering species, it basically consists of a fungal film that spreads across the leaves, stems and other foliage of the plant. Fortunately, however, the ‘dew comes in a variety of different types and while one might devastate your tomato crops, the same strain will have no effect on your cabbages or delphiniums. The most recognisable symptom of this affliction is the titular powder that will surface all parts of the plant and as such one of the most effective control methods is simply to isolate the foliage and remove it from the plant.

picture of rose blackspot

Rose Blackspot

The Black Spot, as much feared by rose gardeners as it was by pirates, is another fungal disease which causes initial discolouration and finally wilt and death in the foliage of most English roses however, floribundas and some species of climbers are known to be most susceptible. Unfortunately the disease is very diverse and thus able to rise to the challenge of chemical control as such, the best method is remove the affected foliage and destroy it.

picture of rust fungus


Rust is one of the most common-place diseases that gardeners must combat due in large part to its genetic diversity, a variety of different strains means that this fungus is able to adapt to a large collection of hosts i.e. allium, bluebell, chrysanthemum, hollyhock, poplar and roses. As the name would suggest, rust fungi occur in the form of orange-brown cysts that degrade the structure of the plant; there are several fungicides available developed to combat this very eventuality.

picture of clematis wilt

Clematis Wilt

Given that another of our other editorials this week is centred on the cultivation of Clematis, it is prudent that we include one of its nemeses here so that you might spot and treat before it has a chance to lay tracks.  CW is a fungal infection whose severity largely depends on the species of your Clematis; the large flowered climbers tend to be the most susceptible while the smaller, earth-bound species, and the spring and autumn flowering climbing types are known for their resilience. When looking for Clematis wilt the most obvious will be the black discolouration it causes in the leaves and stems of the cultivar. Unfortunately there are no quick-fix chemical control options, protection comes during the planning stages by ensuring that the plant is planted deeply (about 15cms lower than the soil level in the pot) and that the soil is well mulched.

picture of box blight

Box Blight

Box Blight is associated, as the name suggests, with Buxus topiary  and hedging plants and its most common symptom comes in the form of brown and eventually bare patches amid the foliage. The most effective treatment is, unfortunately, to remove the plant altogether in order to prevent it spreading to other plants.

Next week’s column will include another list of common garden diseases and potential buffers for them, in the meantime have a thorough examination of your own plants and make sure they don’t suffer from any of those mentioned here.

By Josh Ellison

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