Introduction
Parsnips (Pastanica sativa) belong to the Apiaceae family which also includes carrots, celery and parsley. Parsnips are biennial but are grown commercially as an annual. The edible portion is the enlarged fleshy tap root.
There is good demand for parsnips throughout the year, especially in cooler months. Production is mainly from Wanneroo, Carabooda, West Gingin and Myalup.
Soil, climate and rotations
Parsnips have an effective rooting depth of 35 to 45cm and grow well in deep, sandy soils. A soil pH of 6.0 to 7.0 is adequate for growth. Acid soils should be limed before planting and heavy soils and stony soils are not suitable.
The optimum temperature range for growing parsnips is 16–20oC and the foliage may be scorched above 30oC. Roots are not harmed by frost but cold weather may result in loss of roots due to flowering or ‘bolting’.
The optimum rotation is to include one crop of parsnips in the rotation every four years to avoid diseases such as Rhizoctonia and canker. Do not include too many crops of carrots, celery and parsley in the rotation as these are in the same family as parsnips.
Parsnips are often grown following a well fertilised leafy crop such as brassicas or lettuce.
Varieties
For many years, the major varieties in Western Australia have been the open-pollinated varieties Melbourne Whiteskin and Hollow Crown. Another open-pollinated variety, Dusk, is supposed to be easier to establish in summer when parsnip germination can be a problem.
Newer F1 hybrid varieties that promise better disease tolerance are now also available. Check with seed companies for current varieties.