Good news! Yes, Gardena and Hozelock are cross compatible with one another.
This means if you own a Hozelock hose and wish to buy Gardena accessories to fit it, or vice versa, you can do so without risk of them not fitting.
Sometimes a great way to save money is by purchasing items cheap in the sale (I know I have bought hosepipe bits and bobs at the start of Autumn cheap!)
So if you see any reduced Hozelock or Gardena products and don’t own the other brand, you can be confident that they will fit each other fine!
It is important to buy fittings from the UK and not to import them from the USA as potentially there may be some compatibility issues. The sizing of USA fittings are different to UK ones.
Rejoice in the knowledge that Gardena and Hozelock are indeed interchangeable!