Having recently dug out and replaced some very old, leggy,
too-big-for-the-space lavenders and replaced them with new plants -
these were small (8" dia) and cheap - I'm wondering what to do next to
accelerate their progress if possible. They're all doing fine, have
doubled their bulk since the two months they were planted and have
quite a lotof spindly tall flowers now. But there's no woody growth
here at all - I could easily cut back hard to less than their original
purchased size - it's all green.

With this starting point I'm wondering if there are any tricks to get
these up to a generous bush size ASAP? Cut off a lot after flowering?
Cut back minimally? Do it twice? (late august + spring perhaps?).

I've got 8 of these plants dotted around so I'm up for a controlled
experiment of alternatives if offered.
Grateful for any tips.