Asparagus is a perennial vegetable plant that can be grown at home with ease. Once established, they can be savoured seasonally for up to two decades or more.
The homegrown ones are richer both in taste and flavour than the ones you get at the supermarket.
So are you planning to grow asparagus plants in your vegetable garden? Wondering how to grow them? Well, they can be grown from both the seeds and crowns.
Folk names for asparagus, garden asparagus, scientific name Asparagus officinalis, are a perennial flowering plant species in the genus Asparagus. Its young shoots are consumed as a spring vegetable.
The best aspect of growing asparagus is that they do not need too much care or maintenance like some other veggies.
However, there are some specifications that you need to follow. So, here is a step-by-step guide on growing asparagus at home.
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Here are some recommended varieties of Asparagus that can grow well in the UK climate.
Pacific 2000 (Our Favourite!)
It is a late season variety that produces excellent quality green spears when you plant in early spring. This variety is well-known for being heavy-yielding and exceptionally rich in flavour. You can choose between male and female plants of pacific 2000.
It is a Dutch hybrid that can be planted in the early to mid season. The mid-green, thick spears of this heavy yielding variety often come with closed purple tips. Ginjlim asparagus is a male variety that is preferred in the UK because of its crop flavour and quality.
It is an all-male variety that grows perfectly in the UK and produces straight spears of green colour. Quite flavourful and tasty, backlim asparagus grows in the mid to late season. However, to improve the quality of the spears, you need to wait for the plant to grow.
Guelph Millennium AGM
This variety is more cold-tolerant than others and hence it stands as the most reliable one. As a vigorous all-male variety, it produces crops in abundance in most soils. If you are a beginner gardener, this variety can be the ultimate choice for you.
Connovers Colossal AGM
It’s a heritage variety that produces crops in abundance when you plant at the right season. The bright green spears of connovers colossal asparagus plants are exceptionally large in size and often have deep purple tips.
Now that you know which variety to grow in your garden, let’s explain the right method of planting asparagus. It includes sowing, growing, feeding, caring and propagating.
Asparagus can be grown faster from the crowns than the seeds. If you grow them by planting asparagus crowns, you need two years whereas growing from seeds will need three years before harvesting. Male cultivars produce stronger and better crops and hence, you can choose any all-male variant from the above list. However, if you choose non-hybrid seeds, either male or female plants can grow. If grown from seeds, the seedlings need to be weeded out to get the best results. Here is how you can grow asparagus plants from seeds.
The best time to sow the seeds is in February when the temperature is 13–16°C and the best location is indoors. Before sowing, you need to fill the modules with seed compost and then sow each seed in a single module. In early June, the seedlings will be ready for transplanting or planting out. Before you plan to transplant, you need to prepare the planting site by removing a weed and then digging in one full bucket of organic matter at every square metre. You can choose any garden compost, well-rotted compost or well-rotted manure that’s available.
You can also sow the asparagus seeds outside in March or April by drilling in 2.5cm deep holes in the soil but make sure they are 30–45cm apart from each other. Then, you need to thin the seedlings 15cm apart and after that, they will be ready for transplanting the following March.
The process of growing an asparagus crop will mostly depend upon how well you feed the plants and protect them from weeds. Also, your male plants may need support initially as they grow.
The asparagus bed should be weed free and to ensure that, you can use your hand instead of a hoe. The reason for using hands is that the plants usually have very shallow roots that can be damaged when using a hoe.
Removing Female Plants
Female asparagus plants can be identified by the orangish-red berries they produce. For these plants, you may need to weed out the seedlings with more care. However, if you are planting an all-male variety, you need to remove the female plants if they appear.
Here is another way of keeping the bed weed free. The bed should be mulched in late winter to increase moisture and keep it free of weed. You can use a weed suppressing membrane to cover the bed with it for the whole period from autumn to winter. This method is practised by the gardeners for preventing annual weeds from germinating.
You need to feed the plants with a general fertiliser in early spring. The proportion should be 100gm of fertilizer per square metre. You can choose anything from Growmore or fish, bones and blood. If you notice that the plant growth has got affected, you may need to repeat this process after harvesting.
Supporting and Cutting Back
Since asparagus is a tall and feathery plant, it needs good support during early summer or else the stems may break or the crown may get damaged by the wind. You can create fences using stakes and twine to provide the best support. In autumn, the foliage will turn yellow when you need to cut it down to the level of the soil.
If you want to grow more plants in future, you need to divide the established crowns in winter or spring. However, make sure you do it not more than once in three years. The best method to do it is to dig the soil and prise the asparagus crown into different small sections. Each section should have growing points in it. If you cannot pull apart the crowns, you can try cutting them with a sharp knife. Once done, the crowns are ready to replant.
Growing from Crowns
You can collect asparagus crowns easily from garden centres or online and plant them instantly in March. You can plant the crowns outdoors by creating a dedicated garden bed instead of planting with other crops. Well drained soil with 6.5–7.5 pH and full sun can be the best options for planting the crowns. Also, it’s important to choose fresh ground to control pests.
Start by digging as 30cm deep and 20cm wide trench and then add garden compost to it. After that, make a layer of excavated soil on the top. You need to also create a 10cm high ridge of soil at the centre of the trench. By placing the crowns on top of the ridge, stagger the plants well.
Harvesting asparagus is as easy as planting it because it’s a spring harvest. However, you need to wait for two years after planting asparagus because the plants won’t be ready for harvest. The best time to harvest the plants is six weeks from April when they are three years old. From the fourth year, you can harvest for eight weeks from April. To harvest asparagus in a proper way, take and a sharp knife and cut individual spears of 18cm or lower size. You need to cut them 1inch below the soil surface. During the harvest season, you can harvest spears every two to three days to get the best quality crop.
Common Problems & Remedies
As your asparagus plants grow, you need to take a little more care to protect them from pests and diseases. Asparagus beetles, slugs and snails are the common enemies and hence, you need to get rid of them by trying these remedies.
These 6-8mm long insects are black in colour and they have a red thorax and six blotches of yellow colour. The grey shaded larvae are 1cm long and they have three pairs of legs. The stem and outer barks can be stripped off from the stem when your plant is attacked by these beetles. If you notice any yellowish-brown or desiccated area in your plant, it could be due to a beetles attack.
At the end of the season, you need to burn the old stems to protect your garden from overwintering beetles. You can also find and destroy the pests with your hand from late spring onwards.
Slugs and Snails
These pesky creatures can do severe harm to the crops if left unnoticed. Slugs and snails usually feed on the seedlings and can be easily spotted around or on the leaves or the soil.
There are plenty of organic methods that you can try to control slugs and snails. Some useful methods are eggshell barriers, beer traps, copper tape etc.
Just like pesticides, the frost in spring can also do a lot of harm to young shoots. A late frost can be the reason for crop damages such as poor growth, death and distorted plants.
To protect the garden bed before frost, you can use a horticultural fleece and create a double layer of it on the bed. Also, you can remove the damaged parts of the plants after frost.