Lesson 7ª








Begonias (V)


You should water the Begonia every other day. For the best results, you should try and water them in the morning, preferably before 10 in the morning. You should do this so that the plant is protected during the hottest part of the day.

Plagues and common illnesses

Begonias are always susceptible to certain plagues and illnesses. The fact that they are in pots and that they grow in a prepared earth mixture decreases the risk.

a) Plagues

a.1. Nematodes

They are microscopic animals that usually invade the roots. You will find dark stains on the leaves, which slowly cause the leaf to blacken and dry out. The plant stops flowering and its appearance deteriorates. On the roots you will find small cysts.


It is best to get rid of the plant and prevent the presence of nematodes using a mixture of disinfected earth.

a.2 Flees

They are insects with a coffee colour or green appearance. They appear on the buds or underside of the leaves. They feed on the sap from the plant. They cause stains, the plant to deform and the leaves to turn yellow.


When it is not too serious we can apply a hyssop with alcohol or soapy water to clean the effected parts. If the situation is serious, we should use a chemical that the garden centre recommends to us.

a.3 Scales

This plague is less frequent. They are like brown or grey coloured blisters which stick to the stems and weaken the Begonia as they feed on the plants sap.


Clean the plant with soapy water or alcohol. We can also use some chemical products that exist in the market to eliminate them.

b) Illnesses

b.1. Botritis

It is an illness that attacks the leaves, stems and flowers that penetrates through the wounds caused by pruning. The plant begins to turn yellow. This illness favours humidity and low circulation of air.


We should isolate the plant so that it doesn't infect others. Eliminate the infected parts. Apply a fungicide to prevent any more outbreaks. You should avoid humid places and places where the air flow is weak.

b.2. Rotting stem or crown

This illness occurs when you water the plants too much. You will notice the plant wilting.


You should avoid watering the Begonia too much. However, make sure you water it enough. If there are parts of the plant that we can rescue, elminate the dammaged parts and apply a fungicide or sulphur to the cuts. Make sure you re-plant the Begonia.