How to Grow Asparagus
Posted by Alix Francis on 14th Jan 2019
Asparagus Is a fairly easy to grow perennial vegetable that thrives well in sunny, undisturbed, maintained sites.
You can either grow asparagus in well-drained soil or raised beds, as long as they’re kept well fed and weed-free.
To Get Started You Will Need
- Asparagus Crowns (Typically a year old)
- Fertiliser Granules
- Compost / Organic Matter
Preparing an Asparagus Bed
Asparagus beds should be prepared in advance of planting.
Select an idea area for your asparagus ensuring the ground is completely weed free.
Soil can be improved by adding a bucket of compost or organic matter, per square meter.
Mulching your Asparagus bed in late winter with compost or manure to retina moisture and deter weeds from growing. Cover the soil with an opaque weed mat over winter to prevent any weeds from germinating.
A week or so before planting, scatter general fertiliser granules over the area and fork in before raking the ground level.
How to Plant Asparagus Crowns
Asparagus can be grown from seed; however, it is easier to plant one-year old dormant plants (crowns) in March.
To plant asparagus crowns, dig a trench 30cm wide and 20cm deep.
Fill the bottom of each trench with 7cm of compost or well-rotted manure.
Mound 3cm of the excavated soil on top of your manure or compost to form a ridge down the middle of each trench.
Carefully take the asparagus crowns and sit them 30-45cm apart on top of the mound, spreading the roots on either side.
Cover the crowns with 7cm of soil and firm them into position.
Leave 45cm between your rows and stagger the plants between adjacent rows.
Water well and mulch with 5cm of compost, well rotted manure or organic matter.
How to Plant Asparagus Crowns in Raised Beds
Asparagus can also be grown in raised beds to get started you will need to;
Dig a trench down the centre of the bed then follow the instructions listed above.
Before planting, dig in plenty of well-rotted manure, organic matter or compost to the soil in winter.
Snails & Slugs
These pests feed on young seedlings, look out for their slime trail on the soil around your crop as well as on the leaves too.
Remedy: Slugs and snails can be controlled by beer traps, sawdust, egg shell barriers, copper tape and biocontrols.
Beetles and their larvae strip the outer bark and leaves from the stem of asparagus. Look out for damaged areas which look yellow/brown and desiccated.
Black beetles are typically 6-8cm long with a red thorax and six yellow blotches.
Larvae are grey/black in colour and roughly around 1cm long.
Remedy: Destroy overwintering beetles by burning old stems at the end of the season. Search and remove pest by hand.
Late frosts will damage growth and lead to the plant dying or becoming distorted.
Remedy: Remove any damaged growth and protect the bed with mulch, compost, aged manure or straw.
Keep newly planted crowns well waterer and damp during dry weather.
Avoid harvesting too early as you’ll weaken the crowns.
Allow the asparagus to form ferny foliage during their first two years.
Cut stems down in Autumn leaving around 5cm stumps above the ground.
Always keep your beds weed free to avoid competition.
How to Harvest Asparagus
Avoid harvesting your asparagus for the first two years after planting.
Harvest asparagus spears in the third year from mid-April for six weeks.
Avoid cutting your spears after the end of May as it will weaken the plant.
After 4 years you can fully harvest your asparagus for eight weeks from mid-April each year.
To harvest, cut individual spears with a sharp knife 2.5cm below the soil ensuring the are no more than18cm tall.
During warmer weather, harvest every two – three days for the best quality spears.