Lavenders are short lived shrubs and this year I am replacing mine as they are now woody and scruffy. I am staying with English lavender and 2 of the 3 I will be planting are:
Lavandula angustifolia 'Munstead' is an evergreen dwarf shrub with compact growth, the foliage is silvery/grey in colour and is scented.
Lavandula angustifolia Hidcote is an evergreen dwarf compact shrub its foliage is silvery/grey in colour and has a good scent.

I have a number of different lavender hedges and so do my neighbours and we find the one with the best soft bushy habit is Munstead.

The key to keeping lavenders looking good and not leggy is hard pruning after flowering.

This is the RHS's advice on pruning lavenders

"Lavenders should be pruned every year to keep them compact. On established plants use secateurs to remove flower stalks and about 2.5cm (1in) of the current year’s growth, making sure that some green growth remains. At Wisley, pruning is undertaken in late summer after flowering, although spring pruning is sometimes recommended in books. Lavender does not break readily from old wood and neglected specimens are best replaced. "

While I agree about the pruning Anchorman,I found that no matter how well they are pruned, after about 7 years most will become woody and scruffy, which is about their life span anyway.

I do recognise that given time they must become leggy because they get bigger every year but maybe super careful pruning, very close to what is possible to allow new growth ,would extend their lives a bit?

Do you find these leggy plants actually die? The ones I've seen seem to grow fine but just have horrible leafless central portions.

Speaking only about English lavender, yes I would say they do die. but first its this bare central bit that goes then the whole plant. They are poor soil plants which must shorten their lives.

the lavender growing through the fence in my front garden is really compact and bold but i doubt theyve ever pruned it. mine in the back garden i pruned early spring with little knowledge as i mangled it a bit with the trimmer so its defo hardy lol, its leggy but still bushy and growing. im going to take that advice and give it a careful hard prune after flowering and hope it looks better next year. :o)

Anchorman advice on pruning it is good, just dont cut into the old wood Leigh.

No i wont, ill be very careful and nice to it now i owe it lol :-)

Every year I only take the tip flowers off when past blooming and my lavenders dont get woody.

And take tip cuttings to too make new cuttings.

The varieties of Lavender mentioned are great and the advice given is spot on.

If you want to try another plant like it then Rosemary is great. It is easy to keep bushy and dense and trim and really easy to propagate a new hedge as they grow roots in water. You can also use it in the kitchen (am not actually a fan of the taste).

Thankyou everyone for so much help and information. I want to go out dig up the old and plant Lavanda Angustifolia Munstead now!! maybe I will. I shall remember good advice on pruning I think I did not cut old plants back enough, but also they are about 6years old.

An alternative I read about was the Cat Mint because it has similar flowers. I stop cats rolling on mine, and I have two, by putting hanging baskets over them. The growth comes through the baskets and grows quite bushy but the cats cannot harm it.

I have lots of cat mint, it self seeds easily, so have it everywhere. My cat just presses her face in it and goes into a sort of trance but thankfully no rolling. Thanks for suggestion.