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 July

What To Do In The Garden In July

After all the dry hot weather that much of the country has experienced over the last few weeks, the lavender in David Coton's garden is at its most colourful and scented, he's cutting the flowerheads to make lavender biscuits or drying them for pot pourri. Here are more jobs you can do in the garden during July.

Author: David Coton

Written by David Coton.
Published on Sunday, 25th of June, 2017.

What To Do In The Garden in June

What To Do In The Garden in June

At this time of the year you'll find a fabulous selection of summer bedding at our Garden Centre in Birmingham. David Coton will be planting the bedding in containers this month to achieve a wonderful display of colour and here are some other jobs to do in the garden in June.

Author: David Coton

Written by David Coton.
Published on Wednesday, 17th of May, 2017.

HTA Plant Show 2016

HTA Plant Show 2016

As GardenSIte's plant specialist I always keenly anticipate the HTA National Plant Show. This is my chance to visit nurseries, find out what's trending in the horticultural world and source new stock, all from under one roof.

Author: David Hall

Written by David Hall.
Published on Friday, 24th of June, 2016.

Hampton Court Palace Flower Show 2017

Hampton Court Palace Flower Show 2017

After last night's Preview Evening, Hampton Court Palace Flower Show opens today (4 July), and David Coton is again impressed with how much there is to see for all the family.

Author: David Coton

Written by David Coton.
Published on Tuesday, 4th of July, 2017.

comments powered by Disqus

RSS

View RSS Feed

Author

David Hall David Hall

View Profile

Follow Us!

Recent Articles

GIMA Results 2017

GIMA Results 2017

Robert Hall was delighted to present Westland Horticulture with an award for Best Consumer Product Packaging for their product Westland SafeLawn at the GIMA awards 2017 and who went on to win its top award the GIMA Sword of Excellence.

Author: Robert Hall

Written by Robert Hall.
Published on Monday, 17th of July, 2017.

GardenSite Donates Products To Love Your Garden

GardenSite Donates Products To Love Your Garden

Many of you will have seen the latest episode of the popular ITV series 'Love Your Garden', but did you spot the three items that Robert Hall from GardenSite donated to help transform a Salford garden from wasteland to English cottage garden?

Author: Robert Hall

Written by Robert Hall.
Published on Thursday, 6th of July, 2017.

Party Night with Forest Garden Products at Hampton Court

Party Night with Forest Garden Products at Hampton Court

Robert Hall was recently invited to the party night at Hampton Court as part of Forest Garden Products demonstration event. There they presented their exciting new gardening products, some of which are available now to purchase on GardenSite and others coming relatively soon ready for the next season.

Author: Robert Hall

Written by Robert Hall.
Published on Tuesday, 4th of July, 2017.

Review of Barlow Tyrie Equinox Range of Garden Furniture

Review of Barlow Tyrie Equinox Range of Garden Furniture

Robert Hall, Senior Partner at GardenSite has been selling Barlow Tyrie furniture since 1952 and so has had his fair share of experience of Barlow Tyrie's products, including the popular Equinox range. Robert shares his review of the Equinox garden furniture range for those interested in knowing a little more about this collection before purchasing.

Author: Robert Hall

Written by Robert Hall.
Published on Tuesday, 4th of July, 2017.