"If it's above 7 [pH]
, the iron and nutrients aren't doing the tree ant [sic]
good". This paints with a brush much too broad, and is a little closer to true for plants in potting media than for plants like Gigi N's, which are growing in mineral soil/ the landscape.
Nutrient availability by pH in plants grown in potting media:
Nutrient availability by pH in plants grown in mineral soils:
One thing we CAN say is that dosing with iron sulfate or an iron chelate like Sprint 38 w/o good reason can limit uptake of potassium, phosphorous, calcium, zinc, copper, and especially manganese.
Al
