In a bid to improve both the speed and success rate of germination, I've been sowing parsnips later and later over the years - usually about now, although this year I sowed about a week ago.
That still leaves plenty of time to grow large parsnips where I am - worth sowing 4-5 seeds per station to make sure you get at least 1 plant per station given that even at this time of year they take 2-3 weeks to appear, after which re-sowing might well be a bit on the late side.
Take suitable precautions against slugs and snails - some apparent 'no-shows' are quite likely to be due to their nocturnal feeding excursions.
