How to Grow Asparagus in the UK

How to Grow Asparagus in the UK: Complete Growing Guide

Asparagus is a luxurious perennial vegetable that thrives in the UK climate. While it requires patience (no harvesting for the first two years), an established asparagus bed can produce delicious spears for 20-25 years with minimal care. This comprehensive guide will show you how to grow asparagus successfully from planting to harvest.

When to Plant Asparagus

• Dormant crowns: Plant in March-April (best time)
• Pot-grown plants: Can be planted April-May
• From seed: Possible but adds an extra year; sow in spring
• Male plants preferred: All-male F1 hybrids produce more spears and no seedlings

Soil Preparation

• Soil type: Light, sandy, well-drained soil ideal; won't tolerate waterlogging
• Dig deeply: Work soil to at least 30cm (12 inches) depth
• Remove weeds: Eliminate all perennial weeds - they're hard to remove later
• Add organic matter: Dig in plenty of well-rotted manure or compost
• pH level: Slightly acidic to neutral (pH 6.5-7.5)
• Raised beds: Consider raised beds on heavy or poorly-drained soil
• Permanent position: Choose carefully - plants will be there for 20+ years

How to Plant Asparagus

Planting Crowns (recommended method):

1. Dig trenches: Make trenches 30cm (12 inches) wide and 20cm (8 inches) deep
2. Create ridges: Form a 10cm (4 inch) high ridge along the centre of each trench
3. Space trenches: Allow 45cm (18 inches) between trenches
4. Soak crowns: Soak crowns in water for 30 minutes before planting
5. Place crowns: Sit crowns on ridges, spreading roots down the sides
6. Spacing: Space crowns 30-45cm (12-18 inches) apart along the ridge
7. Cover lightly: Cover with 5-7.5cm (2-3 inches) of soil initially
8. Gradual filling: As shoots grow, gradually fill trench over the season
9. Water well: Water thoroughly after planting

Ongoing Care

• Watering: Water regularly during dry spells, especially in first two years
• Feeding: Apply general fertiliser in early spring; mulch with well-rotted manure in autumn
• Weeding: Keep weed-free; hand-weed carefully to avoid damaging crowns
• Support ferns: Stake tall ferns in exposed positions to prevent wind damage
• Cut down ferns: Cut yellowing ferns to ground level in autumn (October-November)
• Mulch: Apply mulch after cutting down ferns to suppress weeds and feed soil
• Remove berries: Remove red berries from female plants to prevent self-seeding

Common Problems

Asparagus beetle: Orange and black beetles and grey larvae eat foliage. Hand-pick adults and larvae; spray with organic insecticide if severe.

Slugs and snails: Can damage emerging spears. Protect with barriers or organic pellets.

Violet root rot: Fungal disease causing purple fungal growth on roots. No cure; remove affected plants and don't replant asparagus in same spot.

Poor drainage: Causes crown rot. Ensure excellent drainage; use raised beds if necessary.

Harvesting Asparagus

• Year 1: Don't harvest - let all spears grow into ferns
• Year 2: Don't harvest - continue building root strength
• Year 3: Light harvest for 4-6 weeks (late April-early June)
• Year 4+: Full harvest for 6-8 weeks (late April-mid June)
• Spear size: Harvest when spears are 12-18cm (5-7 inches) tall and pencil-thick
• Cutting method: Cut 2.5cm (1 inch) below soil surface with a sharp knife or asparagus knife
• Harvest regularly: Check daily and cut all spears over 12cm tall
• Stop harvesting: Stop by mid-June to allow ferns to develop and feed roots
• Let ferns grow: Allow all later spears to grow into ferns for the rest of the season

Storage

• Fresh is best: Cook and eat within hours of cutting for best flavour
• Refrigerator: Stand spears upright in a jar of water in the fridge for up to 3 days
• Wrapped: Wrap in damp kitchen paper and store in plastic bag for up to 5 days
• Freezing: Blanch for 2-4 minutes (depending on thickness), cool, then freeze for up to 12 months

Recommended Varieties

All-Male F1 Hybrids (recommended):

• Gijnlim: Very popular, heavy yields, excellent flavour, good disease resistance
• Backlim: Early, uniform spears, very productive
• Mondeo: High yields, thick spears, good rust resistance
• Pacific Purple: Purple spears (turn green when cooked), sweet flavour, ornamental

Traditional Varieties (mixed male and female):

• Connover's Colossal: Old variety, reliable, good flavour
• Martha Washington: American variety, rust-resistant, productive