I have already pulled out my Silver Beet because of mould on the leaves - I now have mould on my Dahlias, and a friend mentioned that there is an organic solution to eliminate the problem. Could you please tell me what the solution is? I think she mentioned either baking soda or baking powder - I'd be foolish to assume which she said.
Thank you in anticipation
The silverbeet probably had downy mildew whereas Dahlias probably have powdery mildew - both of which are dependent on the conditions the plants are growing in, and what parts of the plant are affected.
Powdery mildew is most prevalent in hot, dry weather, while downy mildew likes rainy weather and coolness. Powdery mildew appears on the upper surface of leaves while downy mildew occurs on the underside of the leaves.
Powdery Mildew Spray
An effective spray for powdery mildew:
1 litre of water
1 t baking soda
2-3 drops of dishwashing liquid (eco brands preferable)
Mix above ingredients and shake thoroughly. Spray on affected plants to wet mildew thoroughly. Repeat after a week. You can also add 1 t cooking oil for a more effective spray.
The best defense for downy mildew is prevention by the use of compost ‘tea’, good air circulation, morning watering.
In a 10 litre bucket, put 5 litres of compost. Fill the bucket with water. Leave to steep for a few days. Spray liquid onto plants.
Sulphur sprays are also effective in both cases - flowers of sulphur or lime sulphur