Something’s clearly not right with the leaves of this hydrangea. Several of them are all glued or stuck together at the top.
If you look at this photo of the peeled opened leaf cluster, you can see several holes that have been chewed in the leaves, as well as small black dots. That’s caterpillar frass (the polite term for its excrement).
And here, just barely visible, (look for the tiny black head) is the creature known as the hydrangea leaftier.
It doesn’t affect all hydrangeas. As the title of my post indicates, only smooth hydrangeas are susceptible. If you’re not sure what smooth hydrangeas are, they are ones with names like ‘Annabelle,’ Invincibelle Spirit and Incrediball. The botanical name is hydrangea arborescens.
How do you treat these? It’s very simple. You prune them off as soon as you see them. Since this type of hydrangea blooms on new wood, the sooner you catch them, the better it is.
Insecticides are unlikely to work because the insect is so deep inside the leaf pocket so don’t waste your time.
The sooner you get them, the fewer you’ll have. So keep your eyes open if you have this type of hydrangea. A little preventative pruning goes a long way to keeping them happy!