In article ,
Dave Fouchey wrote:

That has been my experience too Paghat, in fact one of the last things
I do before winter is mow down my lavenders, they then explode out of
the ground in Spring, as mine are doing now. the Bronze Fennel on the
other hand always comes from new growth so I leave it up for winter
interest and cut it down in the spring.

Mow 'em down? I've never heard of such a thing! (I should try this...)
When they grow back, how big do they get?

We just planted Lavender down the walkway to our front door. We hope
they'll grow into nice, fat plants. I had several varieties at my old
home and one type of English Lavender (don't remember the variety) just
stayed beautiful, left untouched. It looked great in the winter, too.
The rest needed help, but I never knew you were supposed to prune them!