I could see how that would work for the subsequent year's harvests if allowed to self-seed but with seeds/plants you've sown the first year? I don't see how that would be possible.

FataMorgana

Yeh i agree with that, but it's a first year crop

What i mean is that i plant a row of curly and a row of flat next to eachother and the curly one comes out looking very flat!!

You can tell it's not flat parsley, but it really can't be called curly parsley.

Call it an heirloom semi-curled leaf parsley and sell it for double.