You can start harvesting them anytime now, just taking what you need, and take the opportunity to make a batch of lovely Lemon Vinegar - add a small handful of lemon balm or lemon thyme to the lemon zest. Herb Jellies - either mixed flavours or single variety will be invaluable during the winter months for flavouring casseroles and roasts. Jar into small jars and make a variety to be most versatile.
My most favourite way to preserve the scent and flavour of fresh herbs is to make Herb Salt. Again, very useful - the most useful ingredient - in the kitchen. I keep a jar beside the hob and use it everyday. You will need:-
Around 100-150g/4-6oz mixed herbs of choice, picked over and stalks removed
500g/1lb rock salt
Mixed Fresh Herbs
I used parsley, mint, sage, basil, thyme and coriander
is hard and gritty - used in salt grinders
Process to combine
Spread out onto silicon baking paper or greaseproof paper on tea trays or baking sheets and leave to air dry overnight. This just allows any excess moisture to evaporate.
Finely mixed - pick out any large bits of leaf that have missed the blades
Spread on paper lined trays to dry overnight