How to Grow Asparagus Plants

Asparagus is one of the most highly prized vegetables in the kitchen, known for its delicate flavour and short harvesting season. For gardeners, it represents a crop that requires patience but rewards it with delicious spears year after year. Unlike many other vegetables that are sown and harvested within a single season, asparagus is a perennial plant. Once established, it produces spears every spring for up to twenty years, making it one of the most enduring crops you can grow. Learning how to grow asparagus plants successfully involves careful planning, proper soil preparation and an understanding of the plant’s long term needs. While it demands more effort at the beginning compared to other vegetables, asparagus is one of the most rewarding crops for the patient gardener.

Understanding asparagus plants
Asparagus, or Asparagus officinalis, is native to Europe and parts of Asia. It has been cultivated for centuries, with records of its use dating back to Roman times. The part that we eat, the spear, is actually the young shoot of the plant. Left unharvested, the spear develops into a tall fern like plant with fine, feathery foliage that captures energy for the roots. The root system is the key to growing asparagus successfully, as it builds strength year after year and ensures continued production. Because asparagus is a long lived perennial, it is not a quick crop but an investment that pays dividends over time.

Choosing how to start asparagus
There are two main ways to begin growing asparagus. The first is from seed, which is cheaper but takes longer to establish. Seeds are usually sown in spring, and it can take several years before the plants are ready for harvesting. The second method is from crowns, which are one year old dormant plants sold by nurseries. Planting crowns speeds up the process, allowing you to begin harvesting after two years instead of three or more. While crowns are more expensive than seeds, they are the preferred choice for most home gardeners because they save time and provide a stronger start.

Preparing the soil for asparagus
Asparagus plants thrive in well drained, fertile soil. Poorly drained or heavy clay soil can cause the roots to rot, so improving drainage is vital if conditions are less than ideal. Raised beds are often used for this reason. The soil should be dug deeply and enriched with plenty of organic matter, such as well rotted manure or compost, to provide the nutrients the plants need for long term growth. Asparagus also prefers soil that is slightly alkaline to neutral, so testing your soil’s pH and adding lime if necessary can make a difference. Because asparagus remains in the same spot for many years, investing effort in preparing the soil properly is essential.

Planting asparagus crowns
The best time to plant asparagus crowns in the UK is during spring, from March to May, when the soil is warming up but still moist. To plant, dig a trench around thirty centimetres wide and twenty five centimetres deep. Add a layer of well rotted compost to the base, then create a ridge of soil along the centre of the trench. Place the crowns on top of this ridge, spreading the roots evenly down the sides. Space crowns about forty centimetres apart, with trenches around a metre apart. Cover the crowns with about ten centimetres of soil initially, gradually filling in the trench as the plants grow through the season. This gradual covering encourages strong spear growth and helps establish the root system.

Growing asparagus from seed
If starting from seed, sow indoors in spring or directly outside once the soil is warm enough. Seeds should be sown thinly in rows and covered lightly with soil. Once the seedlings are large enough to handle, they can be transplanted into a nursery bed where they grow for a year before being moved to their permanent position. Growing from seed is more labour intensive and requires patience, but it allows gardeners to raise a large number of plants at a lower cost.

Caring for young plants
During the first two years, the focus should be on building strong root systems rather than harvesting. Water regularly, especially during dry spells, to encourage deep root growth. Keep beds free of weeds, as asparagus does not compete well with them. Mulching with compost or well rotted manure helps retain moisture, suppress weeds and add nutrients. Avoid harvesting spears during this period, as cutting them weakens the plants and delays establishment.

Harvesting asparagus
Patience is rewarded in the third year, when spears can finally be harvested. Harvesting should be done carefully, cutting the spears when they are about fifteen to twenty centimetres tall using a sharp knife just below the soil surface. In the first harvesting year, take spears for only four to six weeks before allowing the plants to grow into ferns again. This ensures the roots continue to build strength. From the fourth year onwards, harvesting can continue for up to eight weeks, usually from late April to mid June in the UK. After this, all spears should be left to develop into ferns to replenish the root system for the following year.

Maintaining established asparagus beds
Once established, asparagus requires ongoing maintenance. Ferns should be allowed to grow freely through summer, as they capture sunlight and feed the roots. They may reach heights of up to two metres and provide an attractive feature in the garden. In autumn, once the foliage has turned yellow, it should be cut down to just above ground level. Removing the old stems prevents pests and diseases from overwintering. A thick mulch of compost or manure should then be applied to the bed to protect the roots during winter and provide nutrients for the following spring.

Feeding and watering mature plants
Asparagus is a hungry crop, and feeding is important to maintain high yields. In early spring, applying a general purpose fertiliser boosts growth. Additional feeding with a high potassium fertiliser during the growing season supports spear production. Watering is especially important during dry spells, as lack of water can cause spears to become thin and woody. However, waterlogging must be avoided, as this encourages root rot.

Pests and diseases
Asparagus beetle is the most common pest affecting asparagus plants in the UK. The beetles and their larvae feed on the foliage, which weakens the plant and reduces future yields. Hand picking beetles and larvae is often the most effective method of control. Other problems include rust, a fungal disease that causes orange spots on foliage, and crown rot in poorly drained soils. Maintaining good hygiene, removing old foliage in autumn and ensuring well drained soil helps reduce the risk of problems.

The long term nature of asparagus growing
Growing asparagus is not for those seeking instant results. It requires a commitment of time, space and effort, particularly in the early years when harvesting is restricted. However, once established, an asparagus bed is one of the most productive and enduring parts of a garden. With proper care, a single planting can provide delicious spears every spring for two decades. Few crops offer such long-lasting rewards, which is why asparagus is treasured by gardeners willing to invest in its future.

The flavour of homegrown asparagus
Supermarket asparagus is often imported and lacks the freshness of spears harvested at home. Asparagus loses flavour rapidly after being cut, which is why homegrown asparagus tastes so much better. Being able to pick spears in the morning and serve them the same day is a culinary luxury. The effort of waiting for the first harvest is more than repaid by the taste of fresh, tender asparagus straight from the garden.

Conclusion
So, how do you grow asparagus plants? The process begins with choosing whether to start from crowns or seeds, preparing fertile, well-drained soil and planting in spring. The first few years focus on establishing strong roots, with harvesting delayed until the plants are mature enough. Once established, asparagus requires careful maintenance, feeding and protection from pests, but the rewards are long lasting. A well-managed asparagus bed can provide delicious spears every spring for up to twenty years, making it one of the most rewarding crops a gardener can grow. With patience and dedication, asparagus becomes not just a crop but a legacy in the garden.