Mammoth Sunflower Leaves Turning Yellow

Hi there, mine do that too. Happens every year. It doesn't bother me. Once they get really gross looking, I trim them off. The sunflowers don't seem to mind at all! Hope that makes you feel a bit better :)

Hi, i had the same problem and the problem was that the plant had an huge root system and was pot-bound, and that caused my plant to die. When i removed it from the pot there was virtually no soil left it was all roots, i threw away the whole thing...
Sunflowers need space, next year i'm planting dwarf variety in pots, mamoth are really more for gardens... I hope this helps....