Q: I sprayed my canna lilies with insecticide every two weeks to control leaf rollers. Is there something better I could be doing? 

A: The cigar-rolled leaves of a canna infested with leaf rollers are really ugly. In addition to spraying, make a note to remove all foliage after the first frost this fall, since the last generation of leaf rollers overwinters in the dead leaves. As soon as you see leaf damage in spring, start unrolling the leaves and destroying the leaf roller caterpillars inside. Both operations will disrupt their life cycle and reduce numbers in summer.