Hydrangea bushes have pod like problem for years now*

(Question)

I have sprayed them repeatedly every year and still only get 1 or 2 small flowers on my annabel bushes. I read somewhere to remove the pod and clean up the ground below, which I will try next year. What do they mean by “clean up the ground below?” Didn’t attach a picture because the pods have now gone end July, I have repeatedly fertilized but it doesn’t seem to do anything?

(Answer)

Thank you for contacting the Toronto Master Gardeners with your inquiry.

The pod-like structures that you see on your hydrangeas are caused by the hydrangea leaf-tier (Exartema ferriferanum) moth. This insect lays its eggs on the hydrangea branches in either the fall or the spring. Upon hatching, the small green black-headed caterpillars sew two terminal leaves together with silk thread, forming the pod-like enclosure that you observe. The catepillars feed inside this enclosure for approximately 10 days before pupation occurs. The moths make their appearance a week later. There is only one generation per year. While the damage does not threaten the plant’s life, it may cause the flower buds to abort.

Please refer to one of our earlier posts for suggestions on how to deal with this pest:

Hydrangea Leaf Tier