I love eating rocket when I go to the restaurant but whenever I have tried to grow it, I ended up with horrible dandelion type leaves, too fiery for my taste. Which type should I be growing?
It sounds like you are growing wild rocket, and it is botanically different to salad rocket, being perennial compared to salad rocket is a biennial. Really they should have different common names.
Restaurant rocket is probably from young plants too and they are less fiery so if you want mild rocket, sow salad rocket every four to five weeks from late June, when it is less inclined to flower.