The earliest sowings can be made under cloches from the end of February, but more reliable results will be had by waiting until mid-March or April.
Mark out your rows by stretching a taut string between two canes and drawing a hoe along the line to create straight drills. Make them about 1cm deep and, if you are sowing more than one row, space each one 30cm apart. Do this on a still day as the papery seeds are easily blown away by sudden gusts of wind.
Place one seed every 2cm along the drill. Alternatively, position three every 15cm – a process known as ‘station sowing’. If the weather is dry, irrigate the rows using a rose-fitted watering can before you start to sow. Cover the drills back over with sieved soil and water for a second time. Mark the ends of each row so you know exactly where the seedlings will appear. This will make it easier to weed around the crop.
You will only need to make one sowing but if space on your plot is at a premium, cultivate radishes or another quick-grower such as cut-and-come-again salad leaves between the rows of parsnips to make maximum use of the ground. These will be long gone before the slow-maturing plants need the extra room.
Parsnips don’t germinate in a hurry, so patience is a virtue here. Expect the first shoots to push through in about two weeks and the final seedlings to make an appearance after another two.
Keep the seedbeds as weed free as possible – remove unwanted plants by hand to avoid disturbing the soil along the rows. Once the seedlings are about 2cm tall you can start thinning the plants to their final spacings. If you have station sown your seeds then take out all but the strongest seedling at each position. Alternatively, if one was sown every 2cm, remove excess plants to leave a seedling every 7cm then, once they have grown on a little, every 15cm or so. Do not be tempted to re-plant your thinnings as they will be unlikely to grow properly.
Early parsnips started off under cloches can have their coverings removed once they have grown a couple of adult leaves. Watering during the early stages encourages even germination and successful establishment of young seedlings. Once they are growing they are a very easy crop to look after.
Keep the young parsnips consistently moist and avoid the roots drying out at all costs or you may attract canker.
You can apply a mulch of grass clippings or similar between the crop to keep the moisture locked in. At all stages keep rows weed free. It’s safest to pull unwanted plants by hand, though light hoeing is also possible as long as you take care not to clip the parsnips’ roots. Damage that creates a wound will leave them vulnerable to canker entry. Any catch crops should be removed as soon as the leaves begin to close over. This will give them enough space as they grow on to maturity.
Although some parsnips can be lifted as early as late summer it is best to harvest after the foliage begins to die down at the beginning of November.
Wait for a few frosts before you begin lifting the roots. This causes the starch to convert to sugar, dramatically improving their flavour. Only lift what you need at any one time, leaving the remainder in the ground.
To unearth a root, insert a fork or spade some distance from the parsnip and rock it back and forth to loosen the soil. They have a firm grip, so you may find you have to literally dig them out to a depth of up to 45cm. Once the first parsnip is out of the ground it is easier to work your way along the row to extract the others.
In very cold parts of the country it’s prudent to lift a few roots early on in the winter and store them under cover in case the ground becomes frozen solid. Trim the tops off the lifted roots then wash and dry them before packing them into wooden boxes of dry sand. Keep these in a cool, dark and wellventilated place such as a garage or shed and eat within a few months.