Grow asparagus by planting one-year-old plants or crowns in spring, at 10 cm deep and about 35-40 cm apart, in single or double rows, with rows spaced 30 cm apart. The crowns are fleshy and must never be allowed to dry out before planting. Dig a small trench with a central, mounded ridge along the flat base, spread out the roots evenly over the ridge and cover them with soil to the level of the crowns. Fill the rest of the trench with soil gradually as the stems grow, always leaving 8-10 cm of the stem exposed.
You can also grow asparagus from seeds. Sow seeds 2.5 cm deep and 7 cm apart, in situ in spring and plant out the largest plants the following spring or sow seeds indoors in modules in early spring at 13-16 Celsius degrees (55-61 F) then plant out in permanent position in early summer.
Asparagus don’t need much attention except that it needs to be free from weeds and when the foliage turns yellow in autumn you need to cut the stems back to about 2.5 cm above the soil.
Harvest asparagus in mid spring, when the spears are about 15 cm high and fairly thick. Cut at an angle, taking care not to damage the nearby spears. You can preserve asparagus by freezing.