How To Grow Asparagus (from Crowns)

Asparagus (Asparagus officinalis) is a perennial vegetable renowned for its tender spears and unique flavour. Cultivating asparagus is a long-term investment, with plants lasting up to 20 years. The key to a rewarding harvest lies in initial patience. Allow new plants a few years to establish themselves before harvesting the first spears. This patience ensures a robust foundation for the asparagus bed, paving the way for years of delicious yields.

Planting

Asparagus is a coastal plant, keeping that in mind, choose a well-drained, sunny location for your asparagus bed. Asparagus thrives in slightly acidic to neutral soil with good fertility (a PH of 6.5 - 7.5 is ideal). If you live near the coast, seaweed makes an ideal mulch for covering your bed over the winter.

As asparagus is a long term perennial crop, you should choose your planting site carefully. It needs a dedicated permanent bed. If you have heavy soil, it's best to make a raised bed to improve drainage.

Prior to planting, clear all weeds from the bed and enrich the soil with well-rotted compost or aged manure.

Plant asparagus crowns in early spring, digging trenches about 30 centimeters deep and 45 centimeters wide. Space the crowns 30-45 centimeters apart to ensure proper growth.

Set the crowns in the trenches with their buds facing upwards, spread roots out evenly, but carefully as they break easily.

Fill in the trench with soil, covering the crowns and leaving the bud tips just visible.

Water well then mulch with a layer of well rotted manure or compost.

Let the crowns develop plenty of ferny foliage so they can establish.

General Care

Asparagus prefers consistently moist soil. Water regularly, especially during dry spells.

Keep the asparagus bed weed-free, as weeds can compete for nutrients and hinder growth. Mulching helps in suppressing weeds.

For the first two years, to encourage lots of foliage, you can feed the plants with Vinasse or OPF 7-2-3. On the third year this can be done after harvesting has finished. The ferny foliage needs to grow big so the plant can put plenty of energy back into the roots for next years shoots.

Harvesting

Avoid harvesting asparagus during the first two years to allow the crowns to establish a strong root system. This patience ensures a more robust harvest in subsequent years.

Cut spears when they reach 15-20 centimeters in height using a sharp knife. Harvest for about 8-10 weeks during the spring, stopping when the spears become thinner.

Trim down the asparagus foliage to 10cm above soil in late Autumn after it yellows. Then cover the bed in a mulch.