all my plants fan leaves are turning a dull yellow color and eventually dying off. What is causing this?
a pic will help but if its at the bottom ist a N deffecieny this can be from rootbound (pot to small), overwatering, and third N deffeciency in the soil. Try pot size before dumping too much ferts in unless if its a massive pot. Rule of thumb is 1 gal of soil per foot of vertical growth.
HIGH All, Other symptoms of Nitrogen deficiency include red stems and petioles, smaller leaves, slow growth. Fertilize with a HIGH N fert and if it is the problem you should see some recovery in 3 or 4 days. Here's what Mel has to say "Although some deficiency symptoms start on the lower, older leaves, others start at the growing shoots or at the top of the plants. This difference depends on whether or not the nutrient is mobile and can move from the older leaves to the active growing shoot. Deficiency symptoms of mobile nutrients start at the bottom of the plant. Conversely, deficiency symptoms of immobile nutrients first appear on the younger leaves or growing shoots at the top of the plant. N, P, K, Mg, B, and Mb are mobile in the plant. Mn and Zn are less mobile, and Ca, S, Fe, and Cu are generally immobile. This is what he said "Deficiencies of mobile nutrients (N, P, K, Mg, B, Mb) begin in large leaves at the bottom of plants. Shortages of less mobile nutrients (Mn, Zn, Ca, S, Fe, Cu) usually begin in young leaves near the top.