2 months ago I took 10 suckers from an old fig tree root, and planted these out. The smaller ones are doing just fine, the bigger ones however.... 5 of the plants are about 4-5 feet tall and had roots about 2 feet long. They keep on trying to set new leaves, but before unfolding, the leaves start to wilt at the tip, and in a couple of days these wilt into a hard little dried leave shell. When I peel the dead leave off, a new fresh and green leaf is underneath. The cycle then continues. It has been 2 months now, the plants keeps on producing new leaves, but none of these unfolds. Any ideas as to what might be wrong?