Common plant diseases

Mosaic virus tends to spread during hot weather. Two of the most common strains are:

• Tomato mosaic virus – affects tomatoes, peppers, potatoes, apples, pears and cherries

• Tobacco mosaic virus– affects beetroot, lettuce, tomatoes, peppers, cucumbers, petunias and tobacco.

• Mottled yellow and green leaves 

• Curled and distorted leaves 

• Stunted plant growth

• Lower yields

• Malformed fruits

• Remove and safely dispose of infected plants – there is no chemical cure available, so early diagnosis is key. 

• Avoid planting susceptible plants in affected areas for at least two years after infection, as the virus can live in dry soil for a long time. 

• Research resistant varieties before investing in new plants.  

• If you are a smoker, wash your hands thoroughly before touching plants vulnerable to tobacco mosaic virus – dry tobacco is also a carrier.

Fusarium wilt is caused by a soil-borne fungus that spreads during the hotter temperatures of summer months. Plants at risk include tomatoes, beans, peas, asparagus and dianthus.

• Wilted leaves 

• Stunted growth 

• Root rot 

• Blackened stem rot

• Remove and destroy infected plants. 

• Be sure to dig up the entire plant with all of its roots.

• Avoid planting vulnerable species in the affected soil for five years after infection. 

• Research disease resistant varieties before planting a new crop.

Verticillium wilt is a fungal disease caused by soil-borne pathogens that restrict water flow in the plant's vascular system. Over 300 species of trees, shrubs, vegetables, field crops and herbaceous ornamentals are susceptible to this disease. 

• Wilting 

• Yellow leaves 

• Foliage falling off prematurely

• Stunted growth

• Prune diseased branches and foliage to help keep symptoms in check. 

• Remember to always sterilise cutting tools between use to avoid spreading the disease. 

• Remove and destroy all affected annuals and perennials.

• Research resistant or tolerant species that can be planted instead.