Modern asparagus is derived from Asparagus officinalis. Native to Europe, it originally grew in coastal sand dunes. Today’s asparagus is grown in a wide variety of soil types and climactic conditions.
Asparagus is a herbaceous perennial plant that can live and produce for many years. Each winter, the foliage dies down. The crown and roots survive until the warmer weather returns and the plant starts to grow again.
New shoots are produced in spring from the energy reserves held in the crown. If allowed to develop, the spears grow into 1.5m tall, attractive fernlike fronds. The fronds produce energy, which the plant uses to increase the size of the crown. The energy is stored in the crown once again for survival through the next winter.
The main requirements for asparagus cultivation are well drained soil and good sunlight. Asparagus responds well to soil enhanced with organic matter and prefers a slightly alkaline pH of 6.5 – 7. Asparagus are partially tolerant of salinity and are marginally tolerant of exposed positions.
Plant dormant crowns in late winter. To plant, prepare a trench about 35cm deep and lay 10 – 15cm of compost or well-rotted manure in the bottom of the trench. Back fill this with existing soil for another 10cm to cover the compost or manure and create a slight mound in the centre of the trench. Place the crown onto the mound so that the roots are spread out and point down at around 45 degrees. Backfill with soil enriched with compost so that the crown is buried to a depth of 7.5cm. Space the plants 45cm apart. Mulch well with lupin mulch to retain moisture and water in well.
Harvest the spears very sparingly in the first year to allow the crown to develop. In subsequent years, harvest only those spears that are thicker than a pencil and about 20 – 25cm tall. Cut with a sharp knife just below ground level and eat fresh or cooked. Allow thinner spears to develop into fronds, particularly later in the season.
Asparagus should be fertilised with a high nitrogen fertiliser in spring prior to spear emergence and again at the end of harvest. Keep the area weed free and well mulched. At the end of the season cut and remove old brown fern spears, add a thick layer of compost and keep moist but not wet over winter in preparation for the following season.
Please note that this is intended as general information only. Please ask one of our qualified horticulturists for more specific advice for your situation.
Want to keep a copy of this information for yourself? Download a copy to your computer.
Why not try growing some Asparagus for yourself?