Epson salt – tell me more. is that to guard against wilt? Every year my plants hit the wall and turn yellow from the ground up no matter what I try.
Long story short, it adds magnesium to the soil, which is necessary for photosynthesis and fruit production. Soils with a high pH (basic) are most at risk of a magnesium deficiency because they are high in calcium and potassium, which rob magnesium from the soil.