What happens to a plant when it has too much potassium?
Certified GKH Gardening Expert
While an abundance of potassium is usually not toxic to plants, too much potassium can inhibit the absorption of other nutrients, which may lead to the nutrient deficiency. The signs of which depends on the type of nutrient the plant is lacking, but includes stunted growth and yellowing of the plant. Here is more info: https://www.gardeningknowhow.com/garden-how-to/soil-fertilizers/plants-potassium.htm