Care and Cultivation of Asparagus
What to do First
Unpack your crowns immediately. Trim off any broken or damaged roots and, if they look dry, soak them for an hour or so in a bucket of water. Aim to plant out as soon as possible. If it is necessary to delay planting for any reason, crowns can be kept for a few days in a cool but frost-free place, such as a shed, if covered with damp material, such as newspaper or sacking. They must not be allowed to dry out.
Soil Preparation and Planting
Asparagus does best in an open and sunny site but where there is some shelter from strong winds. As it is a long-term crop, it pays to prepare the site well, ideally in the autumn before planting. Dig over the ground thoroughly and remove all perennial weeds.
A rich but well-drained soil is necessary for good results, so incorporate plenty of well-rotted organic matter, such as farmyard manure or garden compost. If the soil is heavy, dig in plenty of sharp sand or horticultural grit and, if it is very acid, add lime. Immediately before planting apply a dressing of a balanced compound fertiliser, such as Growmore.
To plant crowns, dig a trench about 20cm (8in) deep and wide enough to take the roots when spread out flat. If you are planting more than one row, space them 90cm (3ft) apart. Now create a mound about 7cm (3in) high along the bottom of each trench. Set the crowns 40cm (16in) apart on this mound, with their roots spread out, and then cover them with 5cm (2in) of soil, firming them in as you go. Make sure they don’t dry out while you are doing this.
Aftercare and Harvesting
As the plants grow, gradually fill in the planting trench, aiming to fill it completely by the autumn of the first year. Hand weed the beds regularly and water well in dry weather. Provide support for the stems in windy areas and, in the autumn, cut down the foliage when it has turned yellow. A mulch with well-rotted compost or manure at this time is beneficial. In March each year, before the new shoots (‘spears’) start to appear, give a further dressing of Growmore.
Do not cut any spears in the first year to allow the plants to establish. In the second year a small number of the largest ones may be cut in April/May but a full crop should not be taken until the third year.
Spears should be cut when they are about 10-12cm (4-5in) tall. Cut them with a sharp knife about 7cm (3in) below the soil surface. Stop cutting in early June and allow spears produced after this to develop into foliage. Cutting later than this will weaken the plants and reduce the crop in the following year. A well tended asparagus bed may well crop satisfactorily for 15 to 20 years.