A Guide To Common Plant Diseases

It’s always disappointing when your carefully tended plants fall victim to a mystery ailment. But this needn’t result in its demise as David Hall finds out. Firstly identify the complaint, treat it and then eliminate the cause.

Created by David Hall on Friday, 21st of August, 2015.


There are diseases specific to particular plants and varieties but here’s a selection of the more common complaints that affect the majority of plants at one time or another. If fungicide should be used I’ve recommended an organic version.

Bacterial Or Fungal Leaf Spot

Leaf spot is self explanatory, they merge into areas of dead tissue and will affect many different plants, causing the leaves to die. Rose growers know it as Black Spot. If caught early it is not fatal for the plant, remove the affected leaves, including any that have fallen on the ground, and burn. If appropriate, spray with a fungicide (dispersible sulphur) and hard prune in the autumn, destroying the cuttings.

Blight

A fungal disease causing yellowing leaves and black spots to appear. Blight spreads quickly amongst the foliage, so deal with this problem immediately, destroying the affected leaves and spraying with Bordeaux mixture.

Clubroot

Mostly affecting brassicas, this is a soil fungal infection that distorts and stunts roots, so inhibiting the plant’s growth. It is very difficult to control. There is no cure but preventative measures include improving drainage and adding lime to reduce acidity.

Downy Mildew

Plants in a cool and humid environment develop yellow / brown patches on their leaves and a mould on the underside that will turn black. This type of mildew will attack and eventually kill the plant. Remove and burn affected parts and ensure good air circulation. Mulch, hand water and avoid nitrogen rich fertiliser.

Grey Mould (Botrytis)

Thriving in damp air, this very common fungal condition presents itself as blemishes followed by grey mould on all parts of the plant. Rot may set in and badly infected stems will kill the plant. Destroy any infected parts both on the plant and ground, and then ensure that air circulation around the plant is improved and humidity reduced. Avoid over watering and nitrogen rich fertilizer.

Powdery Mildew

Leaves are covered with a grey coating usually on the upper surface, the plant’s vigour will be reduced but it should not be prove fatal. It will affect many plants growing in a dry soil. Remove and burn affected parts and spray with dispersible sulphur. Avoid overcrowding around the plant. Mulch, hand water and avoid nitrogen rich fertilizer.

Rust

A fungal infection when leaves and stems develop brightly coloured patches or pustules, causing them to wither and in some cases the plant to die. Again this is a disease that affects a wide range of plants. Remove the affected foliage and destroy,. Allow better air circulation and spray with dispersible sulphur. Rust may be an indication of other problems, so check over the plant.

Silver Leaf

Caused by a fungus that blocks water circulation in trees, the branches will eventually split and die. Look out for a leaves with a silvery appearance, although be careful that it isn’t, ‘false silver leaf’ caused by cold or drought. If it is Silver Leaf, cut off the branches and destroy.

Sooty Mould

This is a fungus and the name derives from its colour. It builds up on the secretions left by aphids. It may restrict growth but is not serious. If you control the aphids the sooty mould will disappear.

Related Articles

What To Do In The Garden In December

What To Do In The Garden In December

Whether it's a bleak December or the more mild weather we are becoming used to, you can still spend useful time in the garden. David Coton suggests the jobs that can occupy the shortening days.

Author: David Coton

Written by David Coton.
Published on Monday, 20th of November, 2017.

What To Do In The Garden In October

What To Do In The Garden In October

In October, David Coton is getting the garden prepared for the onset of colder weather but, at the same time, the arrival of spring bulbs in the garden centre is a reminder that you should also now be planning ahead for next year.

Author: David Coton

Written by David Coton.
Published on Monday, 2nd of October, 2017.

VegTrug - The Easy Way To Grow Your Own Vegetables

VegTrug - The Easy Way To Grow Your Own Vegetables

At GLEE this year David Coton visited the VegTrug stand to find out how their specially designed space saving planters can encourage us to grow more of our own food without the use of pesticides.

Author: David Coton

Written by David Coton.
Published on Thursday, 14th of September, 2017.

What To Do In The Garden In September

What To Do In The Garden In September

The record breaking temperatures over August bank holiday will have got many people out into the garden and, although autumn is only just around the corner, David Coton can suggest these September jobs.

Author: David Coton

Written by David Coton.
Published on Tuesday, 29th of August, 2017.

comments powered by Disqus

RSS

View RSS Feed

Author

David Hall David Hall

View Profile

Follow Us!

Recent Articles

What To Do In The Garden In January

What To Do In The Garden In January

Although the days are short and the view from our Garden Centre is frosty and overcast, Andy Taylor suggests various jobs that can be done in the garden during the month of January.

Author: Andrew Taylor

Written by Andrew Taylor.
Published on Friday, 29th of December, 2017.

GardenSite Donates Christmas Tree To Arthur Terry Winter Concert

GardenSite Donates Christmas Tree To Arthur Terry Winter Concert

Showcasing young musical talent, this year's Winter Concert at Arthur Terry School was an outstanding success and took place against the stunning backdrop of a Christmas Tree donated by GardenSite.

Author: David Coton

Written by David Coton.
Published on Thursday, 21st of December, 2017.

New Street Station Christmas Tree And Selfie Competition

New Street Station Christmas Tree And Selfie Competition

It was quite an honour for GardenSite to be asked to supply the Christmas Tree to Birmingham New Street Station this year, and to celebrate we're offering a Champagne High Tea to the winners of a seasonal selfie competition.

Author: David Coton

Written by David Coton.
Published on Tuesday, 19th of December, 2017.

Garden Storm Damage And What You Should Know

Garden Storm Damage And What You Should Know

With Storm Caroline reeking havoc many people are likely to be contacting their insurance companies at some time regarding damage caused to sheds, greenhouses, fences and other garden property. Robert Hall explains how GardenSite.co.uk can help with an independent insurance quote and claim.

Author: Robert Hall

Written by Robert Hall.
Published on Thursday, 7th of December, 2017.