Can you post a picture?

for now it's too dark but I hope to post one in a couple of days. If I can't save my plants or ever use them again, it would be good to know what it is, so I can prevent such a thing from happening. Will attempt a photo tomorrow!

Mine is blooming now. Maybe yours is about to?

I've never seen any sort of insect issue on a rosemary....other than being visited by bees when in flower. In fact, cold tolerance aside, I can't think of anything at all that bothers this plant if planted in well draining soil and sufficient sunlight.

Wonder if it could be adventitious roots, though I don't remember for sure if they develop along rosemary stems.

I have never seen rosemary produce anything like adventitious roots.....even the prostrate forms.

Without a photo that illustrates clearly what is happening with your plant, all our comments are just speculation ;-)

Just remembered to ask my husband about this; rosemary used to be grown as shrub in the landscape at the university from which he recently retired. He said that adventitious roots were normal on woody stems and that he was often asked about it.

Of course, we have no idea if this is the case with Amanda's plant, since she's not attempted to get back to us. /:-(

Maybe it only does it in warm humid climates. I've never seen it here and Rosemary grows into large bushes.

But as you say, still no picture or further information.