Potassium is an essential element for plants and plays a variety of roles in its life cycle. It is known as a ‘macro’ element and is the ‘K’ part of the NPK ratio.
Potassium deficiency (also known as Potash deficiency) is a plant disorder caused because potassium ions are highly soluble and will easily leech from soils that are light and sandy or chalky/peaty soils that have low clay levels. Potassium supplies an environment for metabolic processes and as such functions as a regulator of various processes including growth regulation. Plants need potassium for protein synthesis, photosynthesis, activation of some enzymes and many other functions.
So how do you tell if your plant is lacking potassium? Here are some symptoms to look out for (remember with a potassium deficiency, symptoms will usually first appear on the older lower leaves):
Brown scorching and curling of the leaf tips, Chlorosis (yellowing) between the leaf veins, Purple spots may appear on the undersides of the leaves, development of the plant/root/seed and fruits are reduced and plants will be more prone to frost damage and diseases when deficient of potassium.
Most of the symptoms can also be confused with the symptoms of wind scorch or drought.
Potassium can also play a part in disease prevention and has also been implicated to have a role in the proper thickening of cell walls. Silica/Silicon, when adequate potassium is present, is incorporated in to cell walls, strengthening the epidermal layer which functions as a physical barrier to pathogens. Adding more potassium will not make it any more resistant to diseases, in fact having too much potassium can be just as bad as having too little.
At Straight Up Hydroponics, we have a range of products for treating a deficiency or for general fertilisation. Pretty much all base feeds and flower boosters contain potassium in some ratio or another as it is simply too important to not include. We stock, as purely potassium additives, RAW Potassium or Canna Mono Potassium. There are others available on our website! You can have a look at what we have available by clicking here!