Dividing A Hosta
One of the thrills of growing hostas (besides all those beautiful varieties) is that they increase in size quickly and can be propagated by division. But their large, dense, fibrous root balls can make dividing hostas a challenge.
I find that the best time to divide or move hostas is in the spring, when they’re in their “spiky” stage – with leaves up out of the ground but not yet unfurled. It’s easier to see what you are doing when the hostas are at this stage, and you can handle them without damaging their leaves. And so, the first day I was able to get out and work in the garden after my return to Maine last week, I set about moving and dividing several hostas. Some of these were being moved to fine tune the garden design, some were being divided because they had outgrown their space, and one, Hosta nigrescens, was being divided so that I could add it to other parts of the garden.
H. nigrescens is a large vase-shaped hosta that makes a bold statement in the garden. It can easily grow to a clump 4-5’ wide and 3’ high, and its flower scapes are typically more than 5’ tall. This is probably my favorite hosta; I prefer it to its better-known offspring like ‘Krossa Regal,’ but it’s very difficult to find in nurseries. So the obvious way to add new plants of this hosta to my garden is to divide an existing clump.
| By the time I got to it, the leaves on this hosta were already beginning to unfurl, making the job of dividing it trickier than it would have been a week or two earlier. The first challenge was to try to get the large root ball loosened up and out of the ground. I used a long handled spade to dig down all the way around the root ball, using the handle as leverage to try to lift it out of the ground. |  |
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There seem to be two schools of thought about dividing plants. One is that you should gently tease the division and its attendant roots apart from the parent plant. The other is that the less the roots are handled the better and that they should be cleanly and sharply cut apart. I subscribe to the “tease apart” school for some plants, like hardy geraniums and daylilies. But I find the root balls of hosta too dense and fibrous to be teased apart; so here I used the surgical division method. Ideally, I would lift the plant out of the ground before I began to divide it; but, even using my long-handled spade for leverage, the 2’ diameter root ball of this plant was too heavy for me to manage. Instead, I used my folding bow saw (which is very sharp and easy to maneuver in tight spaces) to cut the divisions apart while the plant was still in the ground, looking for larger spaces between shoots as likely places to divide. Once a division was cut apart from the parent plant, it could be lifted out of the ground.
I took two divisions from H. nigrescens, together about 1/3 of the original plant. One of these was planted as part of a row of large glaucous hostas along the end of the deck. The other was potted up to await the preparation of its new home in the serenity garden. The remaining 2/3 of the parent plant was left in place, and dirt was filled in around it. The parent plant and the new divisions were all watered thoroughly.
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You can see that some of the leaves on these divisions have flopped over in response to stress. These may recover as the plants grow new roots and get comfortable; if not, the damaged leaves can be removed. (This problem can be avoided by dividing the plants before they leaf out.) In a surprisingly short time, these new divisions of H. nigrescens will grow to be substantial plants of their own.
Jean's Garden 
Hostas really do grow quickly, don’t they? Great photos and instructions!
Useful. Will file under “for future reference.”
Grace, Not all of my hostas grow quickly. In fact, the division of H. nigrescens that I planted at the end of the deck was to replace a division of what was supposed to be H. sieboldiana ‘Elegans’ that was still a runt after 9 years. But, you’re right, that is the exception, not the rule. I’m so happy that H. nigrescens grows quickly because I always have new places that I want to put it.
Susan, I’m pleased that you found this useful.
Great pics and post. Pat and I are always splitting hosta. We can’t seem to get ahead of them. I think it’s all the sweet peet. Have you ever tried splitting in place. We’ll take a chunk (I think that is the correct gardening term) out of a hosta while it’s still in the ground. If you ever want a chunk or two of any of our hosta, just give a yell. jim
Jim, I can easily imagine that you and Pat have trouble keeping up with all your hostas! What do you do with all the divisions after you split them? I guess you could make a lot of people very happy by putting them out in front of the house with a “free plants” sign. Do you ever find yourself tempted to leave them on people’s doorsteps late at night, or perhaps to leave them in unlocked cars like people do with excess zucchini? 🙂
Jean, I can’t tell you how happy I was to see you do a post about this. This is so detailed and wonderful, espeically with the photos. Please do more posts like this, if you are dividing any more perennials!
Hi Diane, If you click on the “dividing plants” tag at the top of this post, you’ll find a few others I’ve done — one on peonies and one on both hardy geranium and siberian iris. Unfortunately, the peony one came early in my blogging experience and I didn’t think to document the whole process with photos.
Very concise and clear explanation. H. nigrescens is one of my favorites too. It is so unique I don’t understand why it isn’t generally available. Hostas don’t all grow the same way. Some form huge rootballs that have to be cut like H. nigrescens. Others when dug up will come apart with gentle pulling, even big plants. I dig mine up and then determine how it grows.
Thanks for the clarification, Carolyn. I don’t have that many different varieties of hostas (about 2 dozen), and mine do all seem to get gigantic root balls. Today, I set out to move one that wasn’t happy in its current location and had hardly grown at all since I planted it several years ago. “Ah,” I thought, “this one will be easy.” I assumed I’d just be able to pop it out of the ground with my garden fork and wouldn’t need my spade; but I was wrong. Even if the plant hadn’t been growing leaves, it had certainly been growing roots; and I ended up with a very large root ball with a tiny plant on top. Is it possible that the large dense root balls are some kind of adaptation to my sandy soil?
I think my philosophy of plant division is similar to yours; dig it up and see what system works best for it.
I have only grown hostas at my garden in PA so haven’t experimented with them in different soils. Seems odd that the plant would grow giant roots and a tiny top.
Jean you are a marvel. I have a fabulous dividing tool from the Netherlands that looks like a flat sharp shovel. I do a similar method with my hostas which need division badly. Sadly I was too late this spring so it will hopefully happen this fall..thx for the reminder and the great pics and step by step…
I have about a dozen that are well past due for dividing. This encourages me to get out my shovel. (Carefully! Carefully!)
My grandfather was always one of those who insisted on dividing plants using the two-garden-forks method, but this looks much easier, especially for a plant with such dense roots. I’ve used my Japanese pruning saw similarly on some plants, and it does make dividing much less physically demanding! Now, I just wish my thumbs weren’t so brown when it comes to hostas, and that we had fewer slugs. Your hostas are gorgeous, and appear to be completely slug-free!
Great post, Jean. I did the same with a very large H. ‘Fried Bananas’ this spring, but I used a very sharp bone-handled knife that belonged to my grandfather. It’s part of my gardening toolkit, and always reminds me of him.
Donna and Helen, I love hearing about people’s special gardening tools.
Patricia, Good luck with dividing your hostas.
Clare, Happily, slugs aren’t much of a problem here. I don’t know whether they don’t like cold, or if my sandy soil is not a hospitable slug environment.
Great idea, Jean. I’m always amazed at gardeners’ resourcefulness when faced with a two-person task that one gardener must complete. I, too, like using two garden forks sunk back-to-back at the point of division. Pushing the handles in opposite directions loosens even the tightest of roots. I’ve used your saw technique on ornamental grasses with some luck. I can see why you like it for large tight-rooted clumps of hosta.
Joene, I have to confess that I’ve never actually tried the two-garden-forks technique — mostly because I’ve never owned more than one garden fork, and it didn’t seem worth buying a second one just to divide plants.
In more than 30 years of living alone, I’ve come to believe that one person can do almost anything if you just think it through ahead of time. I’m still laughing about the time in the 1980s when I realized that it was that one day a year when you could put anything out for the trash pickup — my long-awaited opportunity to get rid of the dead TV (one of those old-fashioned ones in a big furniture cabinet) taking up way too much space in my living room — but none of my neighbors were home to help me carry it out of the house to the curb. Faced with the realization that (a) if I didn’t find a way to get it out to the curb, I was going to have to live with it for another year and (b) it was already dead, so I couldn’t break it, I figured out that I could roll it end-over-end in a kind of controlled fall down the stairs from my second floor apartment and along the driveway to the curb.
Thanks for the tip about H. nigrescens – I’ll keep my eyes out for that one, as I could use some tall vase-shaped types. I have a serrated knife that has been transplanted from the kitchen to my potting bench for help in dividing. Love that thing and how it powers through rootballs. Sometimes the concern is less for what’s best for the plant and more for what works best for the gardener!
VW, H. nigrescens really is hard to find, but it’s worth the effort to look for it; it’s a gorgeous plant. I like your attitude that what works best for the gardener is just as important as what works best for the plant!
Hi Jean, I have used the very method you describe for dividing hostas and other plants. I enjoyed your post and also the comments. I had to laugh at the image of you rolling the TV down the steps and out to the curb. As the old saying goes – where there’s a will, there’s a way!
Deb, I think that may be my unofficial motto — “Where there’s a will, there’s a way.” I joke that this attitude is the result of too many readings of “The Little Engine that Could” at an impressionable age. 🙂
Now why didn’t I think to do that? I just divided a hosta a couple weeks ago and instead of using a knife (which would have made more sense) I took a sharp shovel and drove it right through the middle. Ended up damaging a number of leaf spikes in the process. (although that could have been from the jumping on the shovel!) Got the job done but a saw would have left the plants in much better shape afterward.
Ah, yes, I’ve done that jumping up and down on the shovel maneuver. The sharp implement is definitely easier on the gardener (and probably on the plant, too).
I hacked one of these to death into like 6 pieces and all of them came back. 🙂 I can imagine doing this when they weren’t dormant though would be a huge pain in the butt!
Now that yo mention it, Jess, I can’t remember ever losing a hosta — and I’ve hacked some in my time, too. I wanted to take extra special care with this one, though, because it is so hard to find, so all my divisions are precious.
I use the same tool, a japanese folding saw, on both the hosta and my pot bound agapanthus. A very primitive surgery, but the hosta are renewed and multiply beautifully just like yours!
Jayne, The funny thing is that the folding saw was a gift from a friend, and at the time I couldn’t imagine what I would ever use it for. The answer turns out to be “almost everything!”
Hi Jean,
I wanted to ask you…is there a rule of thumb about divinding the hostas, I mean in terms of how large to let them get before you divide them?
I’ve been noticing that a lot of people are letting their hostas get just HUGE. To the point where they actually look too big, at least for my taste.
Is it just a matter of personal taste?
Diane
Hi Diane, I am no expert on hostas, but I did a little on-line research on this question. There doesn’t seem to be any clear consensus. Apparently, some plants stop growing from the center when they get mature, and they should be divided at this stage to rejuvenate them. (I have never seen this behavior in my own garden — even with hostas that are 15-20 years old.) According to some sources, some variegated hostas lose their variegation when they become mature and need to be divided in order to get the attractive variegation back. As far as size goes, I think it’s a matter of scale and taste. I have seen some gorgeous plantings of huge hostas in settings where the huge size was appropriate and gorgeous. But in my very small Gettysburg garden I’m planning to divide two large ones next spring (even though they’re only about 3 years old) because they’ve just become too large for the space available. -Jean
Thanks Jean. It’s interesting that the research shows that they can stop growing from the middle, etc. The ones I’ve been noticing lately look perfectly healthy. I guess it is just a matter of taste then.
I’m very excited because I’m going on my first ‘garden tour’ on Sunday. It will give me a chance to see some garden’s close-up. I’m a person that loves to look at other people’s gardens from the roadside and wish I could just go up and talk to the gardeners!
I’ll have your advice in mind when the time comes for me.
Hi Jean,
I am new to this blogging world. My gardening friend and I just started a garden blog and I like how you have yours organized.
Susan
http://www.generousgardeners.info
Susan, Welcome to the garden blogging community. I just went over to look at your site, and I love the idea of a space devoted to helping gardeners share their plants. (And it also helped me understand why you chose to leave your message on this particular post. :-)) I am always dividing plants and giving them away, so it’s great to have a new outlet for doing so. As soon as I get a chance, I intend to register on your site. (Maybe I can find some gardeners with some “out of fashion” cultivars that I’d like to add to my garden.)If you haven’t done so, I recommend listing your blog at Blotanical. It’s a very supportive and active community of garden bloggers and will give you excellent exposure to just the audience you want to reach.
Thank you Jean. I will list at Blotanical. I had not heard about it. We are finding it is very hard to be heard with the many voices on the internet.
i have a question about one of my hostas and im hoping you can answer it for me. i would like to know what why there is a stock with a spiky ball growing out of the middle of my hosta, i have never seen one do that before. can you tell me what that might be?
Trish, This is not a phenomenon I’m familiar with — but take a look at this discussion I found on line and see if this might be the explanation: http://www.walterreeves.com/gardening-q-and-a/hosta-strange-growth-in-center/.
For dividing Hostas Watch :https://www.youtube.com/watch?v=eqVkgagZDWI
Excellent post for dividing a hostas and for more information you can check http://bit.ly/1NS8cbp