Asparagus is often considered one of the crown jewels of the vegetable garden. With its delicate spears, refined flavour and reputation as a luxury crop, asparagus is a vegetable that many gardeners dream of growing. While it requires patience and commitment, planting asparagus plants is an investment that can reward you for decades. Once established, an asparagus bed can produce a generous harvest every spring for up to twenty years or more. Understanding how to plant asparagus plants properly is essential, as this is a long term crop that needs careful preparation at the beginning to ensure many years of success.
Understanding asparagus plants
Asparagus, or Asparagus officinalis, is a perennial vegetable. Unlike annual crops that need to be replanted each year, asparagus plants return every spring from the same crown. The spears that we harvest are the young shoots of the plant. If allowed to grow, these shoots develop into tall fern like foliage, which plays an important role in feeding the crown for the following year’s growth. Because it is a perennial, asparagus requires a dedicated bed where it can grow undisturbed for many years. Planting it in the right location with the proper care at the start ensures a productive crop in the long run.
Choosing asparagus crowns or seedlings
Asparagus can be grown from seed, but it is more common and reliable to plant one year old crowns, which are dormant root systems. These crowns are readily available from garden centres or suppliers in spring. Growing from crowns saves at least a year compared to sowing seeds and increases the likelihood of success. Each crown consists of a central bud with long, finger like roots that spread out. When planting, the crown is placed just below the soil surface, where it will establish and send up spears.
Selecting the right site
Because asparagus is a long lived crop, choosing the right site is crucial. It requires full sun and thrives in well drained soil that is rich in organic matter. Waterlogged or heavy clay soil is unsuitable, as crowns will rot if left sitting in excess moisture. A sandy loam is ideal, providing both good drainage and fertility. The site should be free from perennial weeds, as asparagus beds are difficult to weed once established. It is also best to choose a sheltered position, as strong winds can damage the tall ferny growth.
Preparing the soil
Proper soil preparation is essential before planting asparagus. The ground should be dug deeply and enriched with compost or well rotted manure several weeks before planting. Because asparagus crowns can remain in place for decades, the soil should be as fertile and weed free as possible from the start. The addition of grit or sand can improve drainage if the soil is heavy. Testing the pH is also worthwhile, as asparagus prefers slightly alkaline soil. If the soil is acidic, applying lime before planting can help balance it.
How to plant asparagus crowns
To plant asparagus crowns, begin by digging a trench about thirty centimetres wide and twenty five centimetres deep. Inside the trench, create a small ridge of soil along the bottom. Place the crowns on top of this ridge, spacing them about forty five centimetres apart, with the roots spread evenly over the sides of the ridge. Cover the crowns with five to eight centimetres of soil and water gently. As the shoots begin to emerge over the following weeks, gradually backfill the trench with more soil until it is level with the surrounding ground. This method encourages strong root development and allows the plants to establish gradually.
Spacing and layout
For multiple rows, leave about one and a half metres between trenches. This spacing allows room for the tall summer growth and provides enough space for easy access during weeding and harvesting. Good airflow between rows also reduces the risk of disease. Because asparagus is a permanent crop, laying out the bed carefully helps avoid overcrowding and ensures healthy growth over the years.
Caring for asparagus plants in the first years
The first two to three years after planting are a time of establishment rather than harvesting. During this period, the plants focus on developing deep root systems and strong crowns. It is essential not to harvest too many spears in the first two years, as doing so weakens the plants. Instead, allow the majority of shoots to grow into ferns, which feed the crowns through photosynthesis. Regular watering, especially during dry periods, helps the plants settle. Mulching with compost or straw conserves moisture, suppresses weeds and gradually improves soil structure.
Feeding and fertilising
Asparagus is a heavy feeder, requiring plenty of nutrients to maintain productivity. Feeding with a balanced fertiliser in early spring encourages vigorous spear growth. After the harvesting season ends, applying a high potassium fertiliser supports healthy fern development, which in turn strengthens the crowns for the following year. Adding compost or manure each autumn also replenishes nutrients in the soil and helps maintain fertility for the long term.
Controlling weeds
Weeds are one of the biggest challenges in an asparagus bed. Because the crowns are shallow and spread widely, deep hoeing is not possible without damaging the roots. Hand weeding is often necessary, especially during the early years. Mulching goes a long way towards reducing weed growth and is highly recommended for long term management. Keeping the bed weed free ensures that asparagus does not have to compete for water and nutrients.
Harvesting asparagus
Patience is required when it comes to harvesting. In the second year after planting, you can take a very light harvest of a few spears for a week or two. From the third year onwards, the harvest period can extend for six to eight weeks each spring. Spears should be cut when they are about fifteen to twenty centimetres tall, using a sharp knife to cut just below the soil surface. Harvesting should stop in early summer to allow new shoots to grow into ferns, which feed the crowns. Overharvesting weakens the plants and shortens the life of the bed, so restraint is essential.
Summer and autumn care
Once the harvest is complete, the tall fern like foliage should be left to grow freely through summer and autumn. This growth is vital for storing energy in the crowns for the next season. The ferns can reach over a metre in height and may need support to prevent them from toppling in strong winds. By late autumn, when the ferns turn yellow or brown, they can be cut down to ground level and removed. Clearing away the old foliage reduces the risk of pests and diseases overwintering in the bed.
Pests and diseases
Asparagus is relatively resilient but can suffer from certain pests and diseases. Asparagus beetles are the most common, feeding on the spears and ferns and leaving small scars. Regular inspection and handpicking of beetles help keep numbers under control. Fungal diseases such as rust and crown rot can also occur, particularly in damp conditions. Good drainage, proper spacing and removal of old foliage all help prevent these problems. Crop rotation is not possible with asparagus, so prevention is more effective than cure.
Growing asparagus in containers
While asparagus is best suited to open ground, it is possible to grow it in large containers if space is limited. Choose a deep container to accommodate the roots and fill it with a free draining compost mix. Container grown asparagus requires more frequent watering and feeding, as nutrients leach out more quickly. While yields are smaller than in a dedicated bed, it is still a rewarding way to enjoy homegrown asparagus.
The benefits of growing asparagus
The main benefit of growing asparagus is the exceptional taste of fresh spears. Homegrown asparagus has a sweetness and tenderness that cannot be matched by shop bought versions, which are often several days old by the time they reach the kitchen. Growing your own also allows you to enjoy a longer harvesting season, as you can pick spears at their peak. Beyond taste, asparagus is rich in vitamins, minerals and antioxidants, making it a healthy addition to the diet.
Common mistakes to avoid
One of the most common mistakes is harvesting too early or too heavily in the first years. This weakens the crowns and reduces long term productivity. Planting in poorly drained soil is another mistake, as it leads to rot and plant loss. Neglecting weed control also causes problems, as weeds compete strongly with asparagus for resources. Careful planning and patience from the beginning are the keys to avoiding these pitfalls.
Conclusion
So, how do you plant asparagus plants? It begins with choosing a sunny, well drained site, preparing the soil carefully and planting crowns in trenches. The early years are about patience and building strength, allowing ferns to develop and feed the crowns. With proper care, feeding and weed control, the bed will become a long-lasting source of one of the most sought-after vegetables. The reward for careful planning and patience is a crop that can continue producing for decades, making asparagus one of the most worthwhile vegetables to grow at home.
