How to clean the leaves

1 Squeeze a lemon into roomtemperature water – approx 1 tbsp per 100ml – stir and pour into a sprayer. Rainwater is best, but filtered or tap water also works.

2 Spray the liquid evenly over the leaves from 10cm away. Look for stains on the top side of the leaves from previous mistings with tap water.

3 Use a cloth to gently rub the leaves. The limescale should come away, as well as any dust. Rubbing too hard may damage the leaves, but if it proves hard to remove, repeat the cleaning process instead.