How big is your rosemary? I trimmed mine back fairly severely last year in early summer and it didn't appear to suffer at all. I too had some rough looking limbs that had pretty much overgrown its space so I just hacked away until I got it back under control. You might wait until mid-April until all danger of frost is past us.

Thx for the reply---mine look to be old growth---some of the biggest I have ever seen----some of the bushes are 3ft across and 2-3ft tall---at this point I think I will trim back and see what happens----maybe go for a replacement down the road if they don't come back---JE

Some of the branches I trimmed back had spread out larger than 3 feet, so I'd think you'll be ok. Mine weren't quite that large in diameter (the ones I cut), but the bush is still over 7-8 years old and I still get all the rosemary I need from it.

Thx ----I have had some die back due to age, drought and I don't know so i will trim 'em up and hope for the best---JE