Winter is time to divide Asparagus

This may seem back to front if you are not already growing asparagus, so if you are just starting out, then jump over to Planting Asparagus and start there. This is a cycle, so you’ll be back here in about 5 years when you are ready to divide your asparagus plants… after a shiptonne of delicious green spears. 😉

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Asparagus (Asparagus officinalis) is a distant relative of the lily and allium families but sits in its own genus, Asparagaceae. It is a dioecious, rhizomatous, herbaceous, flowering perennial with new shoots edible as a cultivated vegetable crop, then maturing to axial cladodes. Full production from a single crown from year 2 to year 5, after which, separation by division slows the rise of rhizome autotoxicity that otherwise would restrict production, leading to eventual whole plant decline.

>> Winter Golden fronds mean nap time <<

Asparagus fronds turn golden in Autumn — Asparagus fronds turning golden during Autumn

Asparagus is herbaceous, meaning it becomes dormant over winter. In Autumn, the asparagus fronds that are left have turned from green to golden lace. They are just about to sleep for the winter. Usually, we would now cut off the fronds so they don’t rot and attract pests, do some top dressing or trenching between or beside the rows to give them something to snack on when they wake, then tuck up the asparagus crowns with a blanket of straw mulch to keep them toasty, and say goodnight til early Spring.

>> This winter is different <<

The crowns have been in the ground for five years, with each year a great harvest except this last one slowing down. Though you may read that they last 20 years plus, they won’t stay productive if crowded. They’ve been multiplying under the ground, filling out the bed and are now competing for space and food. Time to lift and divide.

Digging up Asparagus to divide — Digging massive asparagus clumps can be hard going, no way round it. A volunteer stevia plant also has to come out.

>> Let’s get dividing <<

We cut the remaining fronds down to sticks, mainly so we can still see where the crowns are. There are five massive clumps in this bed. A fork is the best tool, with a spade to remove excess soil from the bed (more on that in the Planting Asparagus story..)

This clump of 13 crowns came from one small plant in five years. Wowsers.

This one clump is 2 foot wide and very heavy. Use a jet hose to get soil off clumps and see how many crowns there are and where to cut between them. 13 crowns – woohoo.

crowns are separated. — Left: crowded crowns in a clump, Right: separated crowns to replant

We say ‘divide’ but really, we are separating these fresh budding ‘crowns’ which are connected underneath by the darker mature part of the rhizome (underground branching stem). Cut down between the crowns. The roots have fleshy coatings that are very forgiving and resilient, so don’t be precious. I use my Fiskars knife, which is years old, or a Japanese Hori knife would be perfect if you have one. Shove it down between the crowns, like cutting a pumpkin open. Really get in there. From 5 clumps, we got 70 crowns. You little ripper.

NOTE: Rookie error (ask me how I know 🤪) – Feel free to remove any dead roots that are clearly mushy or hollow, but don’t take off root or rhizome just because it is dark in colour. It is the more mature part of the root structure and is still feeding the plant.

Leave any stems that were still a bit green as they will a)mark where you planted the crowns, and b) still have energy returning to the crown. With crowns now apart and tidied up, we are ready to replant. That is another story, and my method differs from most, but it works very well for us. 😉👍