I once sowed parsnips in November and they emerged in March, very nicely.
But you need weed-free soil/compost as the crop seeds are sitting there so long, there is no chance of hoeing or raking.
I am not convinced that the sewing method gives stronger seedlings, since I observe how strong my plants are, from indoor propagation.
But some plants you buy are not strong as they come from heated greenhouses and are grown in compost with artificial fertiliser.
