This is one of life's good things.
I have lavender in pots, but my main lavender event comes in the form of twelve L. angustifolia 'Hidcote' plants that edge the ends of my flower beds.
... That fuzzy softness...it needs off-setting with a tidy lawn (or better still, stone or brick).
L. angustifolia is fully hardy, and covered in deep purple, two-lipped flowers (which you can see are not out yet). The is the perfect time to harvest some stems for drying, (although do leave some for the bees - lavender being ultra-rich in nectar). To dry, just gather a handful, and tie the ends of the stems with a rubber band. Hang it in a cool dry place, upside down for a couple of weeks, and then you can make lavender bags, or get creative in the kitchen.
Here's my lavender sugar (same concept as vanilla sugar) for which I plucked about a tablespoon of lavender buds and added them to a jar of caster sugar. I'll leave that to infuse for a couple of weeks and then make biscuits or ice-cream, or something.
If you want to grow lavender in a container (and look how delicious it is with terracotta), choose a large pot, because you want to allow your plant to grow into a great big wafty hummock, and make it a beautiful one too, because lavender is no flash-in-the-pan plant, and then just mix up some peat-free multi-purpose with John Innes no 2 and keep it watered (though not fed).
Of course, angustifolia is not the only lavender - there is L. x intermedia (often known as English lavender), which is rather smaller, and with rather more rounded leaves, and then there is L. stoechas (or French lavender) which has those funny bunny-eared bracts, - deeply chic, but do watch out, because it is only borderline hardy, and a hard wet winter will nuke it good and proper.
It's nice to sprinkle dried lavender on the floor, or on a table near a lighted candle for scented winter evenings, although with the extended winter we have just endured, I have been using Charlotte and Co's exquisite scented candle from their collection of lovely lavender things, which took me straight to summer whenever I used it. I also have their pillow spray, to which I have become rather addicted, because I am convinced it helps me get to sleep faster, and dream about good things.
I rather long to be a person who wafts around in a silken dressing gown....perhaps this is my little piece of that...silken..ness.
But back to reality...I can't post on lavender without sharing how I prune. This is pretty much the only plant in my garden (bar box) that I am fiercely strict with when it comes to chopping. The problem is that if you don't do it, then you lose that gorgeous mound-thing and you pretty much have to start again with a new plant.
So...when the flowers are over and the bees have had their fill, I cut them all off, (down to the top of the leafy bit of the bush).
Then, at the end of September I chop the whole thing down brutally to about one-third it's original size:
...just like this. You will hate yourself, and it will feel terribly wrong, but it's not wrong, it's right. This way your plant will never get leggy or woody. It will always be like a soft, purple pouffe.