08 Apr, 2021

There are two kinds of blight commonly around Early Blight (Alternaria Solani) and Late Blight (Phytophthora Infestans). Most blights are caused by bacterial or fungal infestations, which usually attack the shoots and other young, rapidly growing tissues of a plant.

Blight diseases primarily affect Tomatoes and Potatoes. With early blight, several treatment options are available, while with Late Blight it’s best to pull your potatoes or tomatoes out and dispose of the plant material (don’t put it in your compost). Early and late refers to when they are more likely to appear, however the two can appear at the same time.

Early Blight can cause leaves to distort and often have dark brown or black spots with a circular ring around them, eventually the lower leaves wither, turn crisp and die. Long thin or spot like markings can be seen on the trunk which have a yellow halo.


Rotate your crops. Plant potatoes and tomatoes in different beds to avoid increased risk of getting blight and other problems.

This fungal disease thrives in wet conditions, so it’s important to keep foliage dry. Try to prevent the leaves from being wet for too long. Water at the base of the plant when possible.

Healthy plants are less likely to be affected, so feed and water plants regularly to avoid them becoming stressed.

Reduce the humidity around the plant by watering in the morning and ensuring that there is good air flow around each plant.

Improve air flow around the plant by leaving sufficient space between each plant, removing laterals on tomatoes, and keeping beds weeded.

Natural Treatment

Early intervention is critical, so act quickly as soon as there are signs of Blight.

Remove and destroy any infected parts of the plant, do not place into your compost.

Spray with Grosafe FreeFlo Copper Fruit & Vegies. Apply at 7 – 10 day intervals depending on weather conditions. Increase volume as crop matures: Ensure coverage of upper and lower leaf surfaces. Repeat spray after 13mm of rain or irrigation has fallen.


Early intervention is critical, so act quickly as soon as there are signs of blight.

Remove and destroy and infected parts of the plants, do not place into your compost.

Spray with Yates Liquid Copper as soon as symptoms appear. Apply every 10-14 days, good coverage is essential.

When using sprays and chemicals always read the label and follow instructions carefully.

Share this post