So, POD hasn’t been entirely happy with the whole alternating weeks of fish emulsion/worm casting tea fertilizing routine. All sorts of secondary deficiencies have been cropping up in POD’s ever-suffering tomatoes. Like magnesium (helped by the addition of epsom salts) and calcium (maybe, or maybe not helped by egg shells) deficiencies, and who knows what else.
A desperate plea was recently lodged with a charmingly hairy farmer guy at Greensgrow. He was incredibly helpful. He suggested this stuff: