I share your thoughts exactly. Should not skip tea during Veg or latest by late stretch. Some plants may not need it but won't harm them if they get it. They'll thrive in fact. But those that do need it and don't get it will freak out and very difficult to shake the deficiency once it starts. Only for larger plants though I've noticed. Small roots in big container with more soil than it needs usually don't need much till harvest in most organic soil recipes.People usually don’t realize it and doesn’t take high amounts but def can’t cut to 0 N in flower! My lowest yielded lately was 1oz in 3gal and was cuz I forgot to do tea all thru veg til like 1/3 way into flower so got really N def! On other hand frosted cookies had many a totally dead leaf from N def but still got nice 30g in half gallon bag and it’s some super potent lemon lime pine trees!
For my grows, i noticed it's always a magnesium + slight nitrogen (if any) deficiency if I don't give tea early. Even with tea, i add some epsom salt. The yellowing between veins from bottom to top with purple stems are a dead giveaway. Rust spots only appear when I ignore the deficiency and let it progress, leading me to believe it's a Mg induced Ca deficiency and not really a Ca def. That explains why it never improves with CalMag but does so with epsom. My experience so far is not to treat a Mg deficiency with CalMag cos too much Ca actually locks out Mg too.
But yeah, teas are a life saver for organic grows for sure!
