An excellent tried and tested variety, Parsnip White Gem has shown that it can be grown successfully in virtually all soil types. Parsnip White Gem also has a very good canker resistance which results in lots of fine, medium length, smooth skinned, high quality, fine flavoured parsnips.For long parsnips you need a deeply dug soil which has been manured for a previous crop. However, they will do well on ordinary well drained and cultivated soil. Sow seeds April to June, 1cm (½ inch) deep in drills 30cm (12 inches) apart. Sow clusters of 4 seeds every 20cm (8 inches) and thin out to the strongest seedlings after germination. Germination is very slow and it is helpful to sow a pinch of lettuce seeds between each cluster of seeds. They will mark the row and can be cut before the parsnips need the room.Germination is very slow and it is helpful to sow a pinch of lettuce seed between each cluster of seeds. They will mark the row and can be cut before the parsnips need the room. Harvest the roots from autumn onwards, leaving them in the ground until required