Potassium is a very important element in all plants. It helps to produce and form colourful flowers and quality fruit and also helps thicken plant cell walls, which improves disease resistance.

Deficiencies can often be noticed in the older leaves (lower leaves on the plant) becoming a dull greyish-green colour with yellow spots appearing on leaf tips and margins. Quite often leaves will look scorched and may die and plant stems can become weak.