Asparagus

Sun

Full sun; tolerates light shade but produces fewer spears.

Water

Water deeply during dry spells, especially while plants establish and while summer foliage is growing. Avoid persistently wet soil.

Soil

Deep, fertile, well-drained soil, ideally sandy loam with a pH of about 6.5-7.5. Improve heavy soil or use a raised bed.

Height

4-6 ft (1.2-1.8 m)

Spread

2-3 ft (0.6-0.9 m)

Flowers

Late spring to summer; small, dangling, greenish-yellow flowers. Female plants may produce red berries.

Foliage

Fine, feathery green growth on upright, branching stems; turns yellow before dying back in autumn.

Growth

Fast seasonal growth once established; allow two full growing seasons before regular harvesting.

Care needed

Medium

• Plant dormant crowns in early spring, spreading the roots out and following the supplier's planting-depth guidance for your soil.
• Keep the bed weed-free by hand; avoid deep hoeing around the shallow roots.
• Water deeply during prolonged dry weather so the summer foliage stays green and active.
• Apply compost or well-rotted manure annually, keeping it clear of emerging shoots; feed after harvesting if growth is weak.
• Support tall foliage with stakes and twine on windy sites, and remove unwanted seedlings.

Pruning. Leave green stems intact after harvesting because they replenish the crowns. Once the foliage has yellowed or browned in late autumn or winter, cut it close to ground level and remove diseased material.

Late winter

Prepare a permanent, well-drained bed and remove perennial weeds before planting.

Early spring

Plant dormant crowns and apply compost around established plants without burying emerging shoots.

Spring

On established plants, harvest spears when about 6-8 in (15-20 cm) tall, before their tips open.

Late spring to early summer

Stop harvesting after about six to eight weeks, or sooner if spears become thin, and let all remaining shoots grow.

Summer

Water during dry spells, support tall stems and inspect regularly for asparagus beetles.

Late autumn

Cut down fully yellowed foliage, remove debris and mulch the bed.

• Plant in a dedicated permanent vegetable bed where routine digging will not disturb the roots.
• Use in a potager, with low annual flowers along the bed edge for contrast with its fine summer foliage.
• Place behind low-growing edible crops, allowing room for the mature stems without shading sun-loving vegetables.
• Grow as a seasonal feathery backdrop in an edible border, with access for harvesting and support.

Garden styles it suits: Potager (kitchen garden), Edible landscape, Homestead, Cottage garden, Farmhouse and Traditional.

Plant it with: Parsley, Basil, Calendula and Nasturtium.

Wildlife: The small flowers attract bees and other insects. Birds may eat the berries and spread the seeds; the summer foliage also shelters small garden creatures.

• Asparagus beetles chew spears and foliage: hand-pick adults and larvae, remove eggs from stems and clear dead foliage after it has died back.
• Asparagus rust causes orange-brown pustules and premature yellowing: choose resistant cultivars, allow airflow and remove infected dead stems.
• Fusarium crown and root rot causes weak growth and declining crowns: improve drainage, avoid overharvesting and do not replant asparagus in an affected bed.
• Thin spears or poor crops usually follow immature crowns, drought, weeds or excessive harvesting: stop cutting, water as needed and let the foliage rebuild the plants.

Young spears are edible for people and are normally eaten cooked. The berries are not edible and can cause stomach upset in people, cats and dogs; sap may irritate sensitive skin. Serious poisoning is uncommon, but keep children and pets from eating berries. Reliable horse-specific toxicity information is limited, so do not offer berries or discarded foliage as feed.

Where it spreads. Can escape by seed and become an environmental weed in parts of southeastern Australia, including parts of Victoria and New South Wales. Remove berries and unwanted seedlings near natural vegetation; do not confuse it with the more widely regulated ornamental asparagus weeds.

• Asparagus fern (Asparagus setaceus)

  An ornamental climber with flattened, lace-like sprays and dark berries, rather than the upright seasonal stems and red berries of garden asparagus. It is not an edible substitute.

• Foxtail fern (Asparagus densiflorus)

  An ornamental asparagus with dense, arching or upright plumes of foliage, depending on the form. Garden asparagus has much looser, taller branching growth; neither plant is a true fern.

Asparagus comes from an ancient Greek name for the plant or its young shoots, while officinalis indicates a historical medicinal use.

Propagation. Grow from seed or plant dormant crowns. Seed-grown plants take longer to reach harvesting size and may include both male and female plants. Established crowns can be divided while dormant, but division damages roots and delays cropping; new crowns are usually easier.

Accepted botanical name

Asparagus officinalis

In the US and Canada

Introduced in Canada, the lower 48 states and St. Pierre and Miquelon.

Native range

Afghanistan, Albania, Altay, Austria, Belarus, Bulgaria, Central European Rus, Corse, Czechoslovakia, France, Germany and Greece.

Measured

Soil pH 7 to 7.5. Average height 90 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.