My seedlings have nice, green leaves. . . . .but with purplish undersides!
How do I correct this deficiency??
I water from the bottom (they have 1+ sets of true leaves) with a complete water-soluble fertilizer (at half strength, this is ~ 7-17-13, with micro-nutrients included).
I let them "drink up" as much as they will, starting with 20 minutes. . thinking that that amount of time would do. It did, for a day or two: then purplish undersides again! Five days later, I bottom fertilized again, but this time let them "drink up" for 30 minutes. Same result: 1-2 days of normalcy, then back to purplish undersides!
I initially choose this complete fertilizer (Jack's Classic Bloom Bust4er) last year over MG Tomato Fertilizer for my mature tomato plants. . . after resolving nutritional deficiencies while "on" MG; once cured and fertilizers switched, my plants did not develop any more deficiencies. So this year, I compared the chemical analyses of MG Tomato and Jack's Classic: while MG offered higher N, it did not list the 2 crucial micro-nutrients but Jack's Classic did.
I'm wondering now if the seedlings need the higher N . . . more so than the micronutrients.
