I did not think that it was worth the space, and would not grow it again. The roots were quite small compared to parsnips and not as tasty.
The seeds are a lot smaller than parsnip seed and they also have the notorious parsley slow germination - and sowing earlier to make up for it doesn't really help because earlier is colder.
If you grow in modules and plant out in April you can end up with a root as big as a medium parsnip - but not in poor soil. Parsnips don't care but H-parsley needs better soil - also if they don't get it they grow slow and tough.
I tend to grow 12 H-parsley plants and use them all in roasts - but I sow a whole load of parsnips - dead easy - and in a good year I dump the surplus (or make wine).
At least 50% of people I know prefer it to parsnip if grown well.
The tops/leaves can be a bit coarse - so OK in stews but not really for salad use.
Cheers.
