How to Grow Asparagus

Asparagus is famous for its gourmet taste – its delicate flavour and texture makes it highly prized.

You can grow it in your own garden and ensure a supply of fresh asparagus – it’s a perennial vegetable and the plants will remain productive for up to 20 years.

We’ve put together this step by step growing guide to help you get started.

When to plant asparagus

Asparagus needs lots of space, making it ideal for a larger garden or allotment – bear in mind that it is a long term vegetable, taking its time to grow to maturity.

The location needs to be well sheltered from the wind, with plenty of sun. The soil should be well-drained. If these conditions do not pertain in your garden, grow your asparagus in a raised bed. Asparagus will not thrive in shade, in clay soils or in pots.

How to plant asparagus

Asparagus is usually supplied in the form of bare root crowns – one-year-old plants. Dig over the ground in the autumn, removing stones and weeds. Dig in well-rotted manure. A week prior to planting, apply a scattering of general fertiliser granules over the ground and work in. Rake over the ground. To plant out asparagus crowns, dig out a hole 20 cm in depth and 30 to 35 cm wide. In the centre of the trench, create a mound 10 cm high. Place your asparagus crowns along the row of the mound, leaving spaces of 30 cm between the rows. Allow the roots to be arranged on either side of the mound, and cover the row of crowns with soil to 5 cm. Gradually fill the trench with further soil as the asparagus stems grow upwards, always leaving the very top of the plant shows so that the trench slowly fills. Leave a space of at least 25 cm between rows.

To grow from seed, plant and grow on in a seedbed for a year. Plant out in April. Soak the seeds in water for two hours, then plant in rows 5 cm deep and 30 cm apart. Thin out the seedlings to be 5 cm apart once they germinate, then 30 cm apart once they are well established and 10 to 15 cm high. One year later, the crowns you will have grown in your seedbed can be transplanted to their final growing positions as per the instructions above.

Harvesting asparagus

Depending on the variety, harvest in the second or third year, when tender. Spears of asparagus should be picked at around 12 cm – use a serrated knife to cut them 5 to 7cm below soil level. In late June, stop harvesting to enable the plant to build up new reserves of energy.

Feed with a general fertiliser at this time to give the plants a new start after the harvesting period.

Don’t harvest the fresh new spears of asparagus which appear early after planting the crowns as this will drain strength away from the plants.

Through the year

Keep your asparagus crowns very well watered when newly planted out. In the first two years, the plants will produce ferny foliage and this should be left to flourish without disturbance.

Cut back the foliage when yellow in autumn. Weed your beds thoroughly as weeds will compete with the asparagus for vital nutrients, light and water.

Handy Tip

Keep new shoots free from slugs with whichever deterrent method you prefer.

Ready to plant your own vegetables now you know how to grow asparagus? Take a look at our vegetable seed collection.