How to Plant Asparagus Crowns: Easy Step-By-Step Guide
Asparagus is an early-cropping, easy-to-maintain, perennial vegetable that will keep producing reliable crops every year for up to 20 years. You’ll be grateful for the time and space invested in your asparagus crop when you harvest those fresh spears in springtime, and with a wide variety of colours and flavours to choose from, they are an excellent and rewarding crop that everyone should try. This year, we’re thrilled to announce that we have asparagus crowns available for purchase, helping to get your asparagus bed established quicker.
Asparagus Seeds vs Asparagus Crowns
You can plant asparagus from seed, but your plants will need 3 years to establish fully before you can harvest, and they will require more care in their first year.
Bare-root asparagus crowns are one-year-old dormant plants that you can use to make your asparagus bed, and you will only need to wait 2 years for them to grow strong and establish fully before harvesting.
Whilst that sounds like a long time, they are such a worthwhile investment as they will keep coming back year after year and need little care to continue providing you with fresh produce.
Where to Plant Your Asparagus
Due to the longevity of asparagus plants, you will want to choose the location of your asparagus bed very carefully as they need room to grow and will need to stay in place for a long time. It is also best not to plant any other crops around asparagus so that they gain all the soil’s benefits, and you don’t want to plant an old asparagus bed with new plants so that you avoid the build up of any soil-borne issues. It is also best to avoid any areas where potatoes have previously been grown.
Asparagus plants like to be in a sunny area, though they can tolerate a small amount of shade, and most soil is suitable as long as it drains well. Raised beds are often preferred as they can help to increase drainage. Organic matter is also key to your asparagus bed preparation; mulch your soil before you plant your crowns, or plant them directly into mulch.
How to Plant Asparagus
Your Asparagus crowns will arrive in April, having been freshly harvested. Remove them from their packaging to allow them to breathe. When you’re ready to plant, soak them in water for 20-30 minutes to rehydrate. If you’ve planted your asparagus from seed, you can use the following steps to plant out your crowns after their first year of growth to establish your asparagus bed.
Dig a trench that is around 20-25cm deep and place a small mound in the centre. The roots of asparagus crowns can be 30cm wide and 20cm deep, so they need room to spread. Put the crown on the mound with the buds facing up and the roots spreading out, and cover with 5cm of soil or mulch initially.
Be sure to leave around 45cm between each crown to give them ample space to grow. Water well after planting and keep the soil moist but not waterlogged.
You want to gradually fill the trench as shoots start to grow until it is level with the surrounding soil. Apply mulch to suppress weeds and retain soil moisture. You want to make sure that your trenches are 45cm apart and stagger the planting between the rows to ensure ample space for your plants.
Water your asparagus crowns regularly during their first summer, but once established, they are drought resistant and will only require watering during hot spells as the roots are shallow and can dry out.
Weed your asparagus bed by hand to prevent competition, and support the fern-like foliage with a twine fence on either side as it grows to prevent it snapping in the wind and damaging your crowns.
In the autumn, cut the foliage back to the stems once it’s turned yellow and mulch the crowns with well-rotted manure. Consider applying a general fertiliser each March to encourage growth before your new spears start to sprout. Female plants have orange-red berries and will produce seedlings that will need weeding out to help your established crowns grow stronger.
Harvesting Your Asparagus
We know it’s tempting to harvest your asparagus early, but your plants really do need time to establish so that you have produce for many years to come. In your crowns’ third year, you can harvest for 6 weeks from mid-April, and you will be able to harvest for 8 weeks from the following year.
Cut your spears with a sharp knife when they reach 18cm or around a finger’s width. When the weather is warm, they will grow quickly and can easily turn woody, so make sure to keep an eye on your bed and harvest regularly. This will also encourage new shoots to grow.
An established plant will provide around 10 spears over the harvesting period.
You can extend your harvesting season by selecting crops that harvest earlier and later, giving you fresh produce for longer. Your harvested spears are best enjoyed straight away, but they will keep in the fridge for a couple of days.
Protecting Your Asparagus Plants
Asparagus crowns are relatively easy to maintain once they have been established, making them an excellent and reliable crop each year. However, they do have a few natural enemies that can cause concern if not handled properly.
Asparagus beetles love to lay their larvae on asparagus plants and eat the wood and foliage. Monitor your plants as they are growing and pick off any larvae or beetles that you see to keep protecting them. Planting basil near your asparagus can help ward off these critters. Slugs and snails can also present a problem and you may want to consider using one of the standard deterrent methods to keep them at bay.
If your soil doesn’t drain properly, then your asparagus roots can rot so ensure that your plants are not overwatered and put the work in when establishing your bed to ensure that it has good drainage.
