How do I add height to an existing asparagus bed?

Question

A month or two ago I planted (1-year old) asparagus in a 6" high raised bed. Now we want to raise it to 30", or more, (easier for my mum to pick).

Would it be a problem? How best to go about it?

Answer 1

According to "the experts," it would be better to start with new crowns. BUT since yours haven't been in the ground that long, they might not be all that established.

Quoting from Asparagus-Lover.com :

Transplanting Asparagus

Transplanting asparagus is exactly what you do when you buy crowns to plant rather than planting from seed. We cover this process on our page on planting asparagus. However this page is all about transplanting established plants or lifting and transplanting your own young plants.

The crowns grown commercially and sold to plant in your garden will typically be one or two years old and clearly transplant absolutely fine. To get them established, growing and harvesting you don’t really want to move them again. Possible reasons for wanting to move your asparagus plants that I have heard cited include: Moving house, planting a bed in the wrong place, planting crowns too close and them not doing very well…. whilst you should do everything to avoid these pitfalls as it will inevitably disrupt your cropping many people report having moved their asparagus plants successfully. If you do need to move your asparagus plants follow this guidance for the greatest chances of success.

What Time of Year to Transplant Asparagus?

You want to move your plants whilst they are dormant ideally in the spring just as or before the soil starts to warm and before the spears start to shoot. Alternatively you can also transplant them in the autumn just as the tops are dying back. One suggested method is lifting in the early spring whilst the ground is still cold and storing for a week or so and then planting as the soil warms up.

Moving established plants during the growing season is not recommended at all.

Transplanting Asparagus Plants - Preparation

Exactly as when starting out with your first asparagus bed you need to do your preparatory work. Take a look at our instructions on choosing the right site and preparing the ground getting everything ready for the big move.

If you think there is any chance of you not being able to identify where each crown is in the spring and you are planning on moving them put a cane into the ground near the centre of each crown in the autumn to make out where you need to dig.

Allow Enough Time to do the Job Well

Do not underestimate the size of the job. If you are transplanting asparagus crowns that are even just a few years old their root structure will have developed and unless the plants are very well spaced they may be quite tangled underground. You need to try to lift the crowns with a little disturbance of the roots as possible. This may take a while.

The reason that transplanting asparagus is not very successful is that the roots can go down by over 1m in depth and up to 2m. You just won't be able to lift them without losing a significant part of their root system and this will weaken the plants for longer than it takes to grow new plants from fresh crowns.

Lifting and Moving your Asparagus Crowns

Use a fork rather than a spade and start by digging gently around one of the crowns at the end of a row. Push the fork in lean on it to raise the earth and ease the roots out of the ground as best you can. Go around the plant in stages easing a little more on each dig. Try to bring as much of the soil and roots with you as you can and tease the roots apart. This can be the tricky bit separating one crown from the one next to it if the roots are very intertwined. You may need to be patient and get stuck in with your hands as well as the fork. Have a bucket on standby to pop the crown in for transportation to its new home. Once lifted take the opportunity to remove any weed roots that are tangled in with the roots and give the crown a bit of a drink of water before placing it in its new position on top of the mound of soil you will have prepared. Gently spread the roots down away from the crown and cover with soil after giving it a final drink of water.

Repeat for each plant then sit back and be patient hoping that your beloved spears will continue to come through. It may be wise not to crop too heavily (if at all) the first year after moving the asparagus to give the plant a chance to re-build its strength.

Please Note the Experts Advice is Don't Try Transplanting Just Plant New Crowns

If you have further questions about Planting and Transplanting Asparagus take a look at our frequently asked questions. If you still don't find the answers you are looking for please feel free to ask and we will try to get you an answer.