Not sure how I do this

[Jasmin82]

I have a couple of culinary plats (mint and lemon balm). On the care instructions it says to trim them regularly to encourage new growth. How do I do this? Do I just trim off some of the leaves? And how do I know for certain when to trim as it says to harvest as required?

Hmmm, with my Lemon Balm, I cut it right back after when it's flowering as it then gets luggy and dry looking. There is plenty of growth near the ground that then grows back more lushly which I will cut back to a couple of inches again before it starts growing in early spring. If mint would actually grow in my garden I would treat it the same, although I think my children would have probably eaten it all before it for a chance.

Mint dies off in the winter and then grows back from the base in the spring, so shoots should be visible, if not quite big by now.
I usually just take a handful of the the top couple of cms for cooking or putting in drinks.
By the time you need more, new sprigs will have grown, as it is fast growing.
If put directly into a flower bed it will spread quickly. It’s best to keep it in a large pot or sink the pot into the ground.
Lemon balm self seeds everywhere, so trim after flowering.

Thank you. I've got both of them inside as if I put them outside, the dog would dig them back up!

Here are a couple of tips on mint, from link below:

Pinch back or harvest the tip of each stem every one to two weeks during the growing season. Pinch back to the second or third leaf set from the tip beginning when the plant grows to 6 inches or taller. Frequent pinching encourages branching, resulting in a fuller plant.

Cut off the flower buds before they open. If allowed to bloom, mint growth becomes open and leggy, while prompt removal helps the plant stay compact. Prune the flower throughout summer as the buds appear.

homeguides.sfgate.com/make-mint-plant-fuller-80816.html