Asparagus is one of those crops which cost a lot in supermarkets so is more cost effective to grow it yourself. It’s not a simple crop to grow, requiring a permanent spot, good soil preparation, space and regular maintenance, but once established they can produce a crop for up to 20 years. You don’t get an a instant harvest either and will have to wait two years before you pick your first spears but after that, you can expect 20 to 25 spears per plant per season especially if all male varieties are grown.
How to Plant Asparagus
Site required for Asparagus
Asparagus will grow in any soil as long as the drainage is adequate, although they perform much better on light sandy soils with a pH of neutral to slightly alkaline. The site should be sunny, sheltered from strong winds and incorporated with lots of compost. Avoid ground that has been previously planted with asparagus or potatoes as this can encourage pests and diseases. All perennial weeds must be removed.
Cultivation of Asparagus
Crowns are planted in early April in pre-prepared trenches as soon as possible after purchase. These trenches should be 30cm (12in) wide, 20cm (8in) deep with an 8cm (3in) mound running along the bottom of the trench for the roots to be spread over. Space crowns 30cm (12in) apart and cover with about 5cm (2in) of soil, filling in the trench in autumn after the season has finished. Each row should be 45cm (18in) apart.
Caring for Asparagus
Hand weed regularly to avoid damage from hoes, water in dry weather and remove berries to prevent self seeding. Once the ferny foliage has turned yellow in autumn cut it down to 3cm (1in) above ground level. In the spring, before the spears appear, make a ridge of soil over the row and apply a general fertiliser at 100g/m2 (3oz/yd2), this treatment can be repeated after harvesting in.
As described above harvesting should only take place two years after planting. After the initial planting of the crowns, spears will shoot but they should not be cut, instead they should be left to develop into the foliage. This should be repeated the following year; it’s only in the second year after plating that your spears can be cut.
The first year of harvest is only about 4 weeks long from late mid April to mid May. The second year of harvest (third year after planting) has a longer period from late April through to early June. Once the spears are 10 to 15cm (4 to 6in) high they can be cut using an asparagus knife by severing the plants 8cm (3in) below the surface of the soil. Stop harvesting the spears in min June and allow them to develop into foliage to provide the plant with energy for the next growing season. Spears do not store well.
Allow the fern emerging from the remaining spears to grow unchecked until the autumn. Strong, healthy fern growth is essential to the long term welfare of the plants. Do not be tempted to cut it for household display with cut flowers! A light dressing of a high nitrogen fertiliser is beneficial in June or July.
In early autumn, as the fern yellows and dies back, the bed can be cleaned up ready for the onset of winter. Cut the dead fern back to within 3in of soil level, and destroy it. Never leave it on the bed itself. Remove any weeds, taking care to avoid deep cultivation, which may damage the roots or crowns. The following spring before growth restarts, mulch the bed if possible with well-rotted organic matter and a further dressing of a well-balanced compound fertiliser.
In the Kitchen
Asparagus has so many uses, but many people eat it in its simplest form – lightly steamed or boiled and served dripping in butter. Hollandaise sauce is a classic accompaniment, and asparagus also makes a superb soup which can be served hot or cold. Or serve the spears warm and wrapped in slices of smoked salmon. They are also wonderful chopped in an omelette or in a soufflé.
Pests and Diseases of Asparagus - Asparagus Beetle, Violet Root Rot, Spindly Spears, Slugs, Frost, Rust, Wind Rock