Asparagus Growing Guide
Asparagus spears are a delicious and juicy crop that, once established, provide reliable harvests every spring for up to 20 years. It is typically planted as one-year-old crowns but can also be grown from seed. The plant requires a dedicated bed with free-draining soil and a sheltered site. Harvests occur for about eight weeks in spring and early summer, with an established plant producing around 10 spears per season. After harvesting, shoots develop into tall ferny stems, which are cut down in autumn to re-sprout in spring.
This guidance applies to the crop in general. Individual varieties and local conditions can differ.
Planting information
Sow seeds indoors in February at 13-16°C in modular trays or small pots with moist, peat-free seed compost, one seed per pot. Keep seedlings warm, well-watered, and in a bright location. Harden them off after the last frost for transplanting in early June. Alternatively, sow seeds outdoors in March or April in drills 2.5cm deep, allowing 30-45cm between rows. Thin outdoor seedlings to 15cm apart and protect from slugs and snails. Replant young plants in March of the following year to achieve final spacing. Plant asparagus crowns as soon as they arrive, ideally in March. One-year-old plants grown from seed can be planted similarly. Dig a hole for each crown, about 30cm wide and 20cm deep. Make a mound about 10cm high in the center of each hole, place the crown on top with growing points uppermost, and spread the roots evenly. Gently cover the roots with soil, leaving just the bud tips visible. Water plants well to settle the soil, then mulch with a 5cm layer of well-rotted manure or garden compost.
Harvesting information
Do not harvest newly planted asparagus for the first two years (three if grown from seed) to allow plants to establish. In the third year, harvest spears from mid-April for six weeks; in subsequent years, harvest for eight weeks. Cut individual spears with a sharp knife 2.5cm below the soil surface when they are no more than 18cm tall or about finger thickness. Harvest every two to three days in warm weather to ensure best quality and encourage new shoots, as they grow quickly and can become woody.