That 'Pine Cone' is Alive (And It's Killing Your Tree)
Brown 'cones' on your Arborvitae? They are Bagworms. Learn why sprays fail on adult bags and how to save your trees before they are stripped bare.
You look at your Arborvitae or Juniper tree. It looks a bit brown. You see dozens of little pine cones hanging from the branches. You ignore them.
Big mistake.
Those aren't pine cones. Those are Bagworms.
The Camouflage Master
The Bagworm is a caterpillar that builds a silk case around itself and sticks needles/leaves from your tree onto the outside. It is perfect camouflage. It lives inside that bag, sticking its head out to eat your tree needle by needle.
Why the Tree Dies
A heavy infestation can strip a tree bald in weeks. Since evergreens (like Cedars and Cypresses) don't regrow their needles easily, one season of Bagworms usually kills the tree permanently.
The Timing is Critical
If you spray them now (when the bags are big and brown), you are wasting your time. The caterpillar has already sealed itself inside to turn into a moth. The bag is waterproof.
You have to hand-pick them.
Grab a bucket of soapy water. Pull every bag off the tree. It takes forever, but it saves the tree. Next year, spray in late spring (May/June) when the baby worms are tiny and haven't built their armored bags yet.