Experts and BHG readers answer.
Leaf curl on fuchsias
It sounds as though your fuchsia may have fuchsia gall mite. This tiny pest, invisible to the naked eye, causes curling and distortion of growing tips on affected fuchsia plants. The mites can spread from plant to plant on hummingbirds, on the wind, or by catching a ride on passers by. It is most severe in cool or cold weather.
Control by cutting back and disposing of the distorted growing tips. Spray with horticultural oil or Sevin every 4 days for at least 2 weeks to kill the existing mites and any new ones which may hatch from eggs.