How To Grow Asparagus

Asparagus growing with runner beans at Levens Hall, Cumbria

Save money and get the taste of summer by growing tender asparagus at home

There’s nothing quite like the delicate flavour of English asparagus to declare that summer is finally here. You don’t even have to conjure up a convoluted recipe for it; just steam and eat with butter or add a bit of prosciutto. As it is so expensive in the shops it makes sense to grow your own. You do need a permanent place for it as you are looking at a fresh planted bed of asparagus lasting for between 20 – 25 years. It is not really suitable for growing in containers as it needs quite a bit of space. They are usually planted in spring but can also be planted in autumn when the soil is still nice and warm.

There are male and female plants; the male bears the best and most spears. You can differentiate between the sexes by the fact that the female bears orange/red berries. Pull up any female plants and any seedlings. Some of the modern varieties available through your garden centre are male.

Position

It needs a sunny, sheltered, permanent site. They also need a new site so if you have grown asparagus previously don’t grow them on the same site. The soil needs to be nice, friable and well-draining; if you have heavy clay you will have to construct a raised bed with plenty of drainage material in the bottom. Prepare the bed well before planting by digging in plenty of well-rotted farmyard manure. Have the ground prepared for planting before the crowns have been delivered as they need to be planted as soon as they are received. Remove all weeds as the growing asparagus must be kept weed-free.

Planting

Dig a trench about 30cm (12”) wide and 25cm (10”) deep and put in a 5cm (2”) layer of well-rotted manure, cover with another 5cm (2”) layer of the soil. Make a ridge down the centre of the trench with the soil, about 10cm (4”) high. Spread out the roots of the crowns and place on the top of the ridge. Plant about 30 – 45cm (12 – 18”) apart. Cover with the soil leaving the tips of the buds visible. Space each row 45cm (18”) apart. Water well and mulch with a 5cm (2”) layer of well-rotted farm manure leaving the buds exposed. They prefer a slightly alkaline soil so test your soil and if it is acidic add a handful of lime before planting.

Aftercare

If there are dry spells remember to continue to water well. Top dress in spring with balanced fertiliser such as blood, fish and bone or Growmore. Apply 100g per sq mtr (3oz per sq yard). Re-apply again when you have finished harvesting. The emerging tips may need to be protected from frost in spring so just cover with a double layer of horticultural fleece. Cut off the tops at the end of summer when they have gone yellow. Keep the bed weed-free by hand weeding as hoeing can easily damage the shallow roots.

Harvesting

Don’t harvest any spears for the first 2 years; let the crown build up its vigour. In year 3 harvest for 6 weeks from the middle of April; from year 4 onwards harvest for 8 weeks from the middle of April, when the spears are about 15 – 20cm (6 – 8”) tall. Use a sharp knife to cut about 2.5cm (1”) below the surface of the soil. When the harvesting period has finished leave the plants to grow and build up the crown for the following year.

Pests and diseases

Slugs can be a problem when the spears are just young so you will have to protect them using your preferred method of slug disposal.

Asparagus beetles are characterised by their red thorax and 6 yellow spots on the wings. They strip the stem and leaves leaving the plant withered and a browny/yellow colour. Burn all the old stems at the end of the season; don’t compost them otherwise the beetles will just over-winter in the compost heap. If you have a large bed you may have to spray with an insecticide specifically for fruit and vegetables, otherwise just be vigilant and pick them off by hand.

Recommended varieties

• Ariane  -  F1 hybrid, green with a purple tip, heavy cropper, can give it a light cut in the first year
• Jacmar Purple  -  sweet and tender due to a low fibre content making almost the whole spear edible
• Mondeo  -  all male, suitable for spring and autumn planting, crops early in the season
• Pacific 2000  -  suitable for spring and autumn planting, good flavour, heavy yield – up to 25 spears per crown

Buttered ham, English asparagus and parsley  -  serves 2   (courtesy of Tom Kerridge)

• 75g (2½oz) unsalted butter
• 2 x 150g (5½oz) pieces of ham; cut into 2½cm (1”) thick slices
• 1 bunch asparagus (8 – 10) spears; woody ends trimmed and peeled
• 2tbsp. fresh parsley; chopped
• 2tbsp. sunflower oil
• 2 free range eggs
• salt & pepper
• 3 small Maris Piper potatoes; cut into very thin strips
• vegetable oil for deep fat frying

1. Add 200 – 300ml (7 – 10fl oz) water to a pan with the butter. Bring to boil, drop in the ham and warm through. Once the volume of liquid has reduced by half and has started to emulsify, carefully remove the ham and add the asparagus. Cook the asparagus for 1 minute. Add chopped parsley at the end. Keep warm.
2. Heat oil in a deep fat fryer to 180C (350F), or in a heavy based pan until a small piece of bread sizzles and goes brown when dropped into the oil.
3. Cook the potato strips in boiling water until soft. Drain and dry the potatoes. Cook the chips in the fat until crisp.
4. Meanwhile heat some oil in a small frying pan. Once hot fry the eggs to your liking.
5. To serve; divide the warm ham between each of 2 serving plates, pile the asparagus next to the ham. Season the ham cooking sauce to taste. Spoon the sauce over the ham and asparagus. Top with a fried egg and a small pile of chips.

If you would like some help growing vegetables, fruit and herbs just get in touch with our Outdoor Plant team.