How to Grow Asparagus Plants

Is It Easy to Grow Asparagus?

Asparagus is a perennial crop that can be surprisingly straightforward to grow with a little patience and the right preparation. It takes time to establish but once settled, it provides an abundant harvest each spring for up to twenty years. While it does need some space and attention in its early years, asparagus is a low-maintenance plant once mature, making it a rewarding addition to any garden.

How and When to Plant Asparagus

Asparagus can be planted either from seed or from crowns. Most gardeners prefer crowns because they give a year or two head start on growth. Planting is best done in early spring when the soil has warmed slightly and is workable. Asparagus prefers full sun and well-drained soil that has been enriched with organic matter. A trench should be dug, then the crowns spaced out and covered lightly with soil. As the plants grow, more soil can be added gradually until the trench is level with the ground.

When Should You Plant Asparagus Plants

The best time to plant asparagus is between March and May, depending on your region and the weather. Soil temperature plays a key role, so it’s best to wait until the ground is at least 10°C. Planting during this window gives the young plants the entire growing season to develop strong roots before going dormant in autumn.

How to Care for Asparagus Plants

After planting, asparagus needs regular weeding to prevent competition for nutrients and water. Mulching with organic material helps keep weeds down and moisture in. Watering should be consistent but not excessive, especially during dry spells. Feeding with a balanced fertiliser during the growing season will help strengthen the plants. In autumn, after the foliage has turned yellow or brown, it can be cut back to just above ground level.

When to Harvest Asparagus

Patience is key with asparagus. In the first year after planting crowns, you should avoid harvesting at all. In the second year, only take a few spears. By the third year, a full harvest can begin. Spears are ready to cut when they are about 15 to 20 centimetres tall and still firm. The harvesting period typically lasts six to eight weeks in spring. After this period, let the remaining spears grow into ferns to nourish the crowns for next year.

Storing Asparagus

Once harvested, asparagus should be used as fresh as possible. To keep it fresh for longer, wrap the stems in damp kitchen paper and place them in a perforated bag in the fridge. Alternatively, stand the spears upright in a jar with a small amount of water and cover the tops loosely with a plastic bag. For longer storage, asparagus can be blanched and frozen for use in soups or other dishes later in the year.

What Common Issues Can You Face When Growing Asparagus?

Asparagus is generally hardy but not without its challenges. The most common pest is the asparagus beetle, which can chew on spears and ferns. Hand-picking or using a safe garden insecticide can help control them. Root rot may occur in poorly drained soils, so good drainage is essential from the start. Weeds are another major problem in young asparagus beds, especially in the first few years. Keeping on top of them will allow your plants to establish and thrive.

What Asparagus Varieties Are There to Grow?

Several varieties of asparagus are well suited to UK gardens. ‘Gijnlim’ is one of the most popular, known for its early and heavy yields. ‘Backlim’ is favoured for its late cropping and disease resistance. ‘Pacific Purple’ offers a colourful twist with sweeter, tender spears, and turns green when cooked. There are also male-dominant hybrid varieties that produce more spears and are often preferred for cropping. Choosing the right variety depends on your climate and when you want to harvest, but all offer the same delicious reward if well cared for.

Preparing the Soil Before Planting

The success of an asparagus bed begins long before the crowns go into the ground. Asparagus prefers sandy or loamy soil that drains well but holds some moisture. Heavy clay soils should be improved with plenty of organic matter such as compost or well-rotted manure. It’s a good idea to prepare the bed in autumn if planting in spring. This allows time for the soil to settle and ensures weeds have been removed thoroughly. Deep cultivation is also key, as asparagus roots can grow quite far down into the soil and need room to spread without obstruction.

Creating the Perfect Planting Trench

When planting asparagus crowns, the trench method is the traditional and most successful approach. Trenches should be around 30 centimetres wide and 20 centimetres deep. A small ridge of soil is built down the centre of the trench and each crown is placed on top with roots spread out over the ridge. A light covering of soil is added initially, just enough to cover the roots, and more soil is added gradually as shoots emerge. This technique helps the crowns establish properly and promotes strong vertical spear growth.

Watering and Feeding Throughout the Year

Asparagus plants do best with a consistent level of moisture, especially during the growing and harvesting season. A layer of mulch can help retain moisture and suppress weeds. Watering deeply but less frequently is better than light daily watering as it encourages deep root growth. Feeding with a high-potassium fertiliser in early spring and again after harvest supports spear development and strengthens the plants for the following year.

Understanding Male vs Female Plants

Asparagus plants are either male or female. Female plants tend to produce fewer but thicker spears, while male plants usually offer a greater number of spears and are often preferred for cropping. Some hybrid varieties have been bred to produce only male plants, which increases yield and reduces the chance of self-seeding. However, if you are growing heritage varieties, both sexes may appear and you may see red berries on female plants in late summer, which should be removed to prevent unwanted spreading.

Extending the Harvest Period

While asparagus has a relatively short harvest window, there are ways to stretch it slightly. Staggering plantings of early and late-season varieties allows you to enjoy fresh spears over a longer period. In larger gardens, some growers even plant asparagus in slightly different microclimates, such as near a south-facing wall or in more sheltered spots to achieve earlier or later cropping. However, it’s important not to over-harvest from individual plants, especially in the first few years.

Encouraging a Long-Lived Asparagus Bed

Once asparagus becomes established, it can produce reliably for fifteen to twenty years or more. Maintaining soil health is the secret to longevity. After the growing season, top-dress the bed with compost or manure to replenish nutrients. Avoid disturbing the roots by digging or forking around the plants. Letting the ferns grow fully after the harvest also helps the plant store energy for the next season. By leaving the ferns in place until they die back naturally in autumn, you support strong regrowth and a better crop year after year.