|I just recently transplanted two palms. Both were|
|I suspect that transplanting in mid-summer, even with addition of iron, was very stressful to your palms. As long as you water them deeply once or twice a week, they should establish and grow well. In the meantime, expect more fronds to yellow as they struggle to survive the summer and to grow new roots. Cut away the yellowing and dead fronds to make the plants look more attractive during their adjustment periods.
Good luck with your palms.