How To Grow Asparagus

Asparagus is a delicious and versatile vegetable that can be easily grown in British gardens. With its tender shoots and unique flavour, growing your own asparagus can be a rewarding experience. It’s one of my favourite crops, as it starts to produce its first spears early in spring, when little else is cropping and can be harvested into early to mid summer. Once you have an established asparagus bed, it’s a real asset and immensely satisfying. Not only does it produce a high quality, tasty crop, but it also cheers the soul by reminding you that summer is fast approaching.

Choosing the Right Variety:

Before starting your asparagus-growing journey, it’s essential to choose the right variety. Some popular asparagus varieties in the UK include ‘Gijnlim,’ ‘Connover’s Colossal,’ and ‘Jersey Knight.’ Consider factors such as taste, yield, and disease resistance when selecting the variety that suits your preferences.

Site Selection and Soil Preparation:

Asparagus thrives in a sunny location with well-draining soil. Choose a site that receives full sun for most of the day. Prepare the soil by removing any weeds, rocks, or debris. Asparagus prefers slightly acidic soil with a pH range of 6.0 to 7.0. Add organic matter, such as well-rotted manure or compost, to improve soil fertility and drainage.

As asparagus is a perennial vegetable, It’s important that you give a lot of consideration to the planting site for an asparagus bed which is likely to be there for many years to come. It is possible to move establised crowns to a new asparagus bed, but new plants quickly sends down very deep roots, sometimes as deep as 10-15 feet. Moving the plant may damage or remove these deep roots, so the move is likely to set the plants back and you may have to practice restraint when cropping for another couple of years. Far better to plan and get them in the right place from the outset.

Planting Asparagus Crowns:

Asparagus is usually grown from crowns, which are one-year-old dormant plants with developed roots. Plant the crowns in early spring or autumn. Dig trenches approximately 30cm (12 inches) wide and 20cm (8 inches) deep. Place the crowns at the bottom of the trenches, spacing them around 30cm (12 inches) apart. Cover the crowns with a thin layer of soil, gradually filling the trench as the shoots emerge.

A lot of people create a ridge of soil over the developing crowns. Growing in the east of England, where we have sandy soils and fairly ideal growing conditions, I have never bothered doing this – but if you’re growing on heavy soil, it may be advisable to do so, to help improve drainage.

Providing Optimal Growing Conditions:

Asparagus requires consistent moisture and good drainage. Water the plants regularly, aiming for about 2.5cm (1 inch) of water per week. Mulching around the plants can help retain soil moisture and suppress weed growth. As the asparagus ferns grow, provide support to prevent them from falling over.

Asparagus Pests

Asparagus beetles inflict substantial harm to plants through their voracious feeding habits. These pests primarily target the young and tender shoots of asparagus plants. Adult beetles lay eggs on the shoots, which hatch into ravenous larvae that devour foliage. This constant feeding weakens the plants, hindering their ability to photosynthesize effectively. As a result, the plants struggle to store sufficient energy for growth and productivity. Repeated infestations over multiple growing seasons can lead to stunted growth, reduced spear production, and, in severe cases, plant mortality.

The defoliation caused by asparagus beetles not only diminishes the plant’s health but also its overall vitality, diminishing the quality and quantity of the harvested asparagus. Effective pest management strategies are crucial to mitigating the detrimental impact of these beetles on asparagus crops. It’s advisable to only use organic pest control methods, as the affected parts are the same ones being consumed. Pyrethrin based sprays are generally effective, particularly when combined with manual removal (and squashing!) of beetles from the asparagus foliage after cropping, as well as scraping off the beetle’s eggs, which can be seen as small black lines on the fronds.

Weed Control and Fertilisation:

Keep the asparagus bed free from weeds to prevent competition for nutrients and water. Regularly remove any weeds by hand, being careful not to damage the delicate asparagus roots.

Apply a balanced organic general fertiliser or a specially formulated asparagus fertiliser in late winter or early spring to give the plants a head start and again after harvesting in early summer to provide the necessary nutrients for healthy growth, helping to develop better spears in subsequent years.

Harvesting Asparagus:

It’s important to exercise patience during the first few years of asparagus cultivation, as the plants need time to establish their root system. Avoid harvesting the spears during the first year to allow the plants to grow stronger. In the second year, you can start harvesting spears when they reach a length of around 15cm (6 inches). Cut the spears just below the soil surface using a sharp knife or asparagus harvesting tool. Harvest over a period of about 6 to 8 weeks, then stop to allow the remaining spears to develop into ferns. From the third year onwards, you can extend the harvest period to 8 to 10 weeks.

Fern Care and Winter Maintenance:

After the harvest season, allow the asparagus spears to grow into fern-like foliage. These ferns capture sunlight and convert it into energy for the plants’ future growth. In autumn, cut back the ferns to ground level and remove any debris from the bed. Mulch the bed with organic matter to protect the plants during winter.

Growing asparagus in your British garden can be a rewarding and long-lasting endeavour. By following these steps, you can cultivate a thriving asparagus bed and enjoy a plentiful harvest of tender and flavoursome spears year after year. Remember to choose the right variety, prepare the soil adequately, provide optimal growing conditions, and practice regular maintenance. With time and care, you’ll savour the delightful taste of homegrown asparagus in your favourite dishes.