growing parsnips

I love parsips but haven't tried growing any. When is the best time to sow?

Mine normally get sown in about early April.  The soil is too wet and cold before then to make good germination, and they catch up happily enough with earlier-sown ones.

I was toying with trying parsnips next year, but my ground is clay with lots of stones. I know that's not ideal conditions for parsnips, but will they just grow misshapen under those conditions, or not at all?

I grow mine in flower buckets in a mix of home-made compost with sharp sand and get great results. If you want to grow them in your clay soil take a crowbar or similar and ram it into the ground then wiggle it about to give a cone-shaped hole approx. 3-4 inches across at the top. Fill this with sand/compost mix and sow a couple of seeds to each hole. Thin out to the strongest seedling.

I know it sounds a faff but having stony clay soil is no reason not to grow parsnips 

why not get some free flower buckets from asda they are about 18" deep and maybe 10/12" dia fill them with your own custom made dirt, and off you go 3 or 4 per pot

I have finally nailed straight parsnips.

I pre-germinate the seed and plant them in kitchen roll tubes filled with compost.  When the first true leaf opened they were planted into a deep raised bed.  I like to cram mine in and were planted no more then 20cm apart in all directions.  Dug up my first 2 today. 
 
The first snapped off about 18 inches down but was HUGE.  The second came up easily and was 2 feet long from crown to tip and dead straight.  Again it as a whopper. 

Last year I was plagued with fanged roots, but signs this year are more encouraging.

I know you can leave snips in over winter, but what happens to the foliage? Mine are looking good but all the (high and dense) foliage has flopped over into my leeks in our raised bed after recent frost - should I just leave it, tie it up, cut it back??!   :blink:

Ah, good tip, hadnt thought of that!  I doubt they will be getting much goodness from the foliage where they are - feels like its been dark here for about a week now, and they are in a pretty shady patch    Surprised I've got anything at-all actually!