My lavender is getting very tatty looking what would be the best way to revive it?
do not cut back to hard as it will kill the lavender.clip back the straggly flower stems but not into the hard wood.
Make sure that you trim it back to leave a few new little green leaves near to the main stem. If you cut it back more than that the branch that you have trimmed will die.
I like the Italian method. Cut just below the flowers after flowering is over. Leave the plant to overwinter. In spring, just as the plant is coming back to life, cut again down to the first sign of new growth, taking all last year's growth. This prevents floppy, woody plants. Once they get floppy and woody it's hard to resurrect them.
Don't ever cut into old wood.
I read on the site a while back that if it's very bad, you can dig it up and replant it deeper into the soil so that the woody bits are covered and its new growth will form a nice clump again. Of course it will always get woody again after a few years but it does work and you would continue to prune it every year but never cutting into the old wood as already mentioned.
You'd need to be careful digging it up. Lavender is notorious for not liking its roots disturbed.
Thank you all for your very helpfull advice.I think that i will try trimming it back and if it looks no better next year i will try the burying way.Any other advice would be welcome.