Can I trim flowering herbs?

[AugustIsNeitherHereNorThereIFeel]

I had a herb garden built in my garden a few months ago. We thought we wouldn’t be able to use them this year, but they’ve grown tenfold and gone nuts.

I came back from holiday to them doubled up, and they are now flowering on the ends (especially basil and mint). I trimmed the coriander when flowering and it’s now dried up and died.

Any tips?

Once the bees have finished on the mint flowers, I would cut it back hard to the ground. If you do it in two halves you’ll have some to harvest whilst the other half regrows. Basil and coriander are annuals so once they have flowered they die. You may be able to salvage the Basil by trimming off the flowers now. I hope your mint is contained as it will take over if not.

You should always harvest the leaves from the top, and pluck off the flowers as soon as you see them, or keep pruning so they never appear. Once it starts flowering it will stop producing new leaves I think. So try and stop it happening if possible.

Coriander is an annual, it would die off after flowering anyway. It bolts (flowers then dies ) very easily this time of year. You have to keep sowing it successionally. Basil you can usually keep going a bit longer.
Mint will grow like mad more or less whatever you do.

Bit worrying that who ever built this didn't give you any guidance at all. If it were clients I worked with, they'd be given care guidance and info on what to expect

Basil won't cope with any cool weather either (let alone cold). It's one i only ever have indoors. I'd replace the basil and coriander with rosemary, thyme, chives and/or sage. They're all perennial and not too crazy - hopefully the mint is contained! I just get potted herbs cheaply from the supermarket and plant them out, splitting them if needed. You can also plant spring onions from the supermarket, if you just use the green part they will regrow.