Tomato blight identification on fruit and what to do. Time-lapse

Tomato blight is weather-dependent and can be devastating during wet summers. Watch out for signs on outdoor tomatoes, which are most at risk; glasshouse tomatoes are less likely to become infected though the spores are carried in the wind and will enter through open windows and doors.

Tomato blight on leaf

Tomato blight on leaf

Early Blight can affect the foliage, stems and fruit of tomatoes.

Symptoms: Dark spots with concentric rings develop on older leaves first. The surrounding leaf area may turn yellow.

Affected leaves may die prematurely, exposing the fruits to sun scorching.
Management: Early Blight fungus overwinters in plant residue and is soil-borne. It can also come in on transplants. Remove affected plants and thoroughly clean fall garden debris. Wet weather and weak stressed plants increase the likelihood of attack. Copper and/or sulfur sprays can prevent further development of the fungus
Late Blight is caused by a fungus, Phytophthora infestans. It’s the same disease that led to the Irish potato famine almost 150 years ago.

The disease is not directly harmful to people as it only infects potatoes, tomatoes, and some related weeds, but it is not advised to eat the infected fruit or tubers.
It is important to catch any tomato disease early, before it spreads to all of your tomato plants and possibly other plants in the same family, such as potatoes, eggplants and peppers.
Look for brown, rapidly spreading patches on leaves and stems. The fruit, too, may show firm, quickly spreading brown patches followed by rotting. Infected parts die rapidly.
Destroy infected plants; but do not compost them as the plant residue is soil-borne and will spread the disease to your next years crop.
Late blight needs living plant tissue to survive, so infected tomato plants should be destroyed as soon as the disease is identified. In small gardens, this means removing plants in trash bags and sending them to the landfill;

By Time-lapse by Neil Bromhall

I have made an on-line interactive plant finder, identifier and pruning guide web site. which I hope you find interesting.

It has over 3,600 garden plants, 10,000 photographs plus time lapse sequences and each plant has in-depth plant care and illustrated pruning advice.

The plant database is continuing to grow.  If you have good quality photographs of garden plants that are not not already on the database I’d like to hear from you with an interest of adding it to the collection.

Contact me on

2 Responses to Tomato blight identification on fruit and what to do. Time-lapse

  1. […] Margherita last night. The problem, Ann said, is blight. It hits your plants unless you cover them. Neil Bromhall’s blog here on WordPress explains blight […]

  2. hillwards says:

    Hi I found this entry when trying to identify what was eating the lower leaves on our tomato plants, which show similar discolouration. Fearing blight, we rushed to cut off the affected leaves, but further investigation revealed that these markings actually indicate magnesium deficiency rather than anything more sinister. Spraying the foliage with epsom salts or seaweed feed every couple of weeks should help redress the balance. The problem can be made worse by modern tomato feeds which are apparently rich in phosphorus, which the plants take up in favour of magnesium. I realise this post is a couple of years old, but I hope this information is helpful!

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