Asparagus is usually supplied in the form of bare root crowns - one year old plants. Dig over the ground in the autumn, removing stones and weeds. Dig in well-rotted manure. A week prior to planting, apply a scattering of general fertiliser granules over the ground and work in. Rake over the ground. To plant out asparagus crowns, dig out a hole 20 cm in depth and 30 to 35 cm wide. In the centre of the trench, create a mound 10 cm high. Place your asparagus crowns along the row of the mound, leaving spaces of 30 cm between the rows. Allow the roots to be arranged either side of the mound, and cover the row of crowns with soil to 5 cm. Gradually fill the trench with further soil as the asparagus stems grow upwards, always leaving the very top of the plant shows so that the trench slowly fills. Leave a space of at least 25 cm between rows.
To grow from seed, plant and grow on in a seedbed for a year. Plant out in April. Soak the seeds in water for two hours, then plant in rows 5 cm deep and 30 cm apart. Thin out the seedlings to be 5 cm apart once they germinate, then 30 cm apart once they are well established and 10 to 15 cm high. One year later, the crowns you will have grown in your seedbed can be transplanted to their final growing positions as per the instructions above.