· Brooks Wilson's Answer
· Hi Joan,
Your problem could be leaf roller caterpillars. Cannas are largely free of pests, but the plants sometimes fall victim to Canna leaf rollers. It is the larva that is known for chewing straight rows of holes on canna leaves. Most types feed as solitary caterpillars, but some feed in groups. Solitary types feed on leaves by rolling, folding, or tying them together before eating them. during the day, they reside on the underside of leaves, and they are active at night. Infested leaves appear shredded from the cocoon-like web made by the leafroller. Young leaves are so damaged, they cannot open and may die. Infested plants are unable to bloom and appear quite ugly. Unless monitored for signs of caterpillars, it is easy to miss the first generation because the caterpillars are already inside tightly rolled leaves below the visible growing point. Second and third generations are more obvious because damage is easier to see and more extensive.Affected leaves can be cut off and destroyed or unrolled and cleaned (by removing the caterpillar), though some gardeners prefer to use an insecticide.
If it's not leaf roller caterpillars It may as Stephen mentioned be too much water or it could be root bound, meaning it's out grown the container.
Hope this helps you out.