Peter from Redmond Oregon writes
It would not be necessary to add Epsom salt when fertilizing with Peter's Professional 10-30-20 because the product already contains magnesium in it. Magnesium is essential to plant development to help the plant produce chlorophyll. If you feel like you absolutely need to use Epsom salt, we would recommend to do a soil test first. Soils with a pH above 7 and soils high in calcium and potassium also generally have low magnesium levels. Calcium and potassium compete with magnesium for uptake by plant roots, and magnesium often loses. Sometimes, a soil test will show adequate magnesium levels in soil, but a plant grown in that soil may still be deficient because of that competition.
Answer last updated on: 09/19/2016
