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how to grow asparagus guide

'How To' Grow Asparagus

asparagus

Asparagus fetches high prices in the supermarkets, but why pay when you can cut your own crop straight from the garden? Growing asparagus in the UK is simple, and once established, asparagus beds are relatively low maintenance.

It does have several demands - a permanent spot, plenty of room to grow, and just a little patience. But don’t t be put off, as just a single row of 10-12 plants can easily start to produce a decent crop in as little as two years. Indeed, few vegetables will give you such a good return on your initial investment. Once established, asparagus plants will produce tender, tasty spears for up to 20 years!

Read on for our top asparagus growing tips that will help you to get the best from your asparagus plants.

Which Asparagus Plants to Grow?

Asparagus Variety Characteristics
Asparagus officinalis 'Pacific 2000' Voted the best variety in commercial grower taste tests of 2006.
Asparagus officinalis 'Ariane' Purple-tipped spears early in the season.
Asparagus officinalis 'Pacific Challenger' One of the most disease resistant varieties - tolerant to Phytophthora and Fusarium.
Asparagus officinalis 'Guelph Millenium' Particularly cold tolerant and well suited to UK weather condiitons.
Asparagus officinalis 'Pacific Purple' Stringless purple spears that are more tender and sweet than many green varieties.
Asparagus officinalis 'Connover's Colossal' (Sore's Selection) A very well maintained strain of this popular old favourite.
Asparagus officinalis 'Mondeo' Impressive yields and quality, especially early in the season.

When to Plant Asparagus

Why bother growing asparagus from seed when most varieties are available as bareroot crowns. Bareroot Asparagus crowns are traditionally planted in the spring, but can also be planted in autumn while the soil is warmer to give your plants a head start on establishing. Therefore most varieties are available to order for either spring or autumn - whichever you prefer.

Planning an Asparagus Bed

Asparagus is a perennial vegetable which will need a permanent place in the garden. Once delivered, asparagus crowns are best planted as soon as possible, so it’s worth preparing the ground well in advance.

Choose a sheltered, sunny position on fertile, well drained soil. Don’t worry if your soil is not perfect. You can dig in plenty of well rotted manure or garden compost into the soil to improve soil structure and fertility. If you are gardening on a cold, wet soil then the addition of sharp sand or grit will help to improve drainage.

It’s also worth making sure that the ground is completely weed free before planting asparagus crowns as it will be much harder to rectify this problem later on when the plants begin to grow.

asparagus spears in the ground

How to Plant Asparagus Crowns

Asparagus enjoys really good drainage so it is best planted in trenches of around 20cm (10") deep by 30cm (12") wide. Fill the bottom of each trench with 7cm (3") of well rotted manure or garden compost to help feed the plants in future years. The excavated soil can then be mounded up on top of the manure to form a ridge along the length of the trench.

Place each asparagus crown on top of the ridge with their roots draped over the edges. Asparagus plants will need plenty of space in the coming years so lay them out at a distance of 45cm (18") apart. Cover the crowns with 7cm (3") of soil and then firm them into position before watering well to settle the soil.


Growing Asparagus Crowns

asparagus foliage

Throughout the growing season your asparagus plants will need a little attention, but they are not particularly demanding.

  • Spring: Feed with a general fertiliser each March.
  • Summer: Asparagus plants have relatively shallow roots so it is important to keep them well watered during hot periods, to prevent them drying out. The shallow roots can also be easily damaged by using a hoe, so it’s always best to weed asparagus beds by hand - that’s why it is so important to start with a weed free asparagus bed even before planting!
  • Autumn: Cut back the yellowing foliage and mulch the crowns with well rotted manure to protect them from frost.

Harvesting Asparagus

harvest asparagus spears

Asparagus spears should be cut when they reach around 15cm (6") tall. Cut spears individually at about 2cm below ground level. You can buy special asparagus knives to make this job easier but any sharp knife will do. Asparagus spears are fast growing so you will need to check your crops every day during the harvest season.

  • Year 1: When growing asparagus, it’s important to resist the temptation to harvest the spears during their first season. Instead, allow the plants to develop foliage as this will help to feed plant and encourage stronger, healthier growth next year.
  • Year 2: A limited crop of spears may be harvested in the second year during April and May when they reach 15cm (6") tall.
  • Year 3: By the third year, the crop can be fully harvested. It is recommended to stop cutting from the end of May though to allow the shoots to develop into foliage. Later harvests can be made, but this is at the risk of weakening the plant and therefore it may not crop so well in the following year.

Growing Asparagus in Containers

Asparagus is always best grown in the ground, but if necessary it can be grown in large pots or patio bags (at least 60ltrs) for a limited time. This can be handy if you want to grow a crop on the patio or if you can’t justify giving your asparagus plants a permanent space in the vegetable plot. Take a look at our Asparagus Planter Collection.

When grown in permanent beds, apsaragus crowns will crop for up to 25 years. However asparagus growing in containers has a limited lifespan and should only be expected to crop for approximately 3 or 4 seasons after its 2 year establishment period.