There was a need to re-plant a line of lavender earlier this year.  I spotted some lavender planted with what looked like petunias(hard to spot as I was driving at the time) so I thought that I would give it a go.  The new plants were very small when I planted them in April so adding a petunia plant between each lavender fill the space quite well.  As I type this I can see the plants and they are really doing their stuff and look just wonderful.  The colours of the petunias work so well with the blue of the lavender.  The under gardener wants to do the same again next year but I think it will not work .  I can now see how people with plenty of money to spend could rip it all out and do it just the same again next year.  I, on the other hand, cannot so next year it will just be a line of now larger lavender plants.