Q.Leaf curling on Yellow Canna lily
We have orange, yellow and red canna lilies. TGIF orange are showing lots of new growth but the red is showing none and the yellow is showing new leaves but they are curling (horizontally not vertically).
Insects can cause stunted growth on plants. Curled leaves are usually a sign of an insect invasion such as by canna leaf rollers, which curl the foliage around themselves and feed inside. More information on leafrollers and treatment options can be found here:
Canna plants can also become infested with aphids, which can cause leaves to discolor, distort and curl. More information on aphids and recommended treatments can be found here: https://www.gardeningknowhow.com/plant-problems/pests/insects/homemade-aphid-control.htm
For more information on the care of canna lilies, please visit the following link: