Do nutrient deficiencies cause leaf discoloration?

Nutrient deficiencies can turn healthy leaves into fragmented patches resembling a canvas. Calcium deficiencies produce interveinal white patches, which are white ghostly designs between the veins. Magnesium deficiencies cause foliage to yellow, where the margins of the leaves go yellow first. I misdiagnosed a client's hydrangea because I mistook these signs as sunburn incidents. Soil tests showed that some nutrients were locked up by pH.

Soil testing prevents errors in diagnosis. Someone I know poured Epsom salts on their roses and did not get better, they created worse iron deficiency. Lab analysis will test for 14+ nutrients and that's where educated guesswork can start and stop. For around $25 I can have my local extension service conduct an analysis and provide a report on the results. Then I will source those nutrients on their recommendations instead of guessing what I think I saw.

Use gypsum in wet soil for calcium. Gypsum works to build soil structure and will not change the pH. For magnesium applications, foliar sprays are more effective than soil drenches. I always mix 2 tablespoons of Epsom salt with a gallon and spray it on the leaves in the morning as the sun is coming up. You then apply every three weeks until the veins green up.

Initially stop repeat issues, targeting your use of balanced fertilizers. "Complete" formulas should include sufficient secondary nutrients. I predominantly use 5-5-5 combined fertilizers for most ornamentals. For edibles, you can just apply compost as a side dress midway through the season. You will see your plants' leaves broadcast when they are healthy with non-inhibited growth.

Read the full article: White Leaf Spots: Causes and Solutions