Hosta are incredibly durable plants, especially the older varieties. I’ve seen hosta survive after sitting in a clump of dirt without a pot for weeks. So it’s the easiest thing in the world to divide hosta and transplant them.
Should you divide your hosta?
Before we get into how to divide hosta, the question is should you. Most hosta take about 5 years to reach their mature size. Often gardeners will get a bit hosta mad and start dividing their hosta every time there’s more than two or three eyes. When you do that, you’re really cheating yourself of the full show your hosta has to offer.
If your hosta isn’t crowding out or being crowded out by other plants, best to just leave it alone. If it just isn’t spreading as fast as you would like, try this. Lift the root ball out of the ground, divide it into two or three clumps. Replant all in the same area with a bit of a gap between them, maybe half the expected mature spread of the variety you are spreading. The hosta will continue to do it’s thing, but now you’ll have 3 individual crowns grouped together and they’ll look much more substantial.
Why are you dividing your Hosta?
If your hosta truly needs to be divided, my next question is what are you doing with the divisions? Are you dividing and spreading through your own yard or are you giving away the divisions.
If your hosta has a name, it most likely has a patent. Growers and nurseries that sell hosta all pay royalties to the breeder. That’s how breeders get compensated for the time and effort they’ve put into developing that plant. Breeders might cull thousands of less satisfactory plants before they produce one good enough to trial. They might then trial that variety for years before they consider sending it for tissue culturing.
At the end of the day, it’s your garden and your plants, but personally I don’t divide my hosta to give away ‘free’ plants. My mother has hundreds of varieties, and beyond sharing some of the more common varieties among ourselves, she doesn’t give away ‘free’ hosta either. Even if I had enough to bother selling them, I wouldn’t. Bottom line it’s stealing from the breeder to do so.
When to Divide Hosta
Spring really is the best time to divide hosta. Hosta will survive division later in the season just fine, but dividing in the spring has the least impact on appearance. A hosta divided just as the pips emerge will leaf out in it’s usual rounded mound. A hosta divided after the leaves emerge will have either a flat side or a hole where the division was taken.
Often, the leaves that were out when the hosta was divided will remain limp. With water and care, new leaves will grow over the season but it’s going to look ugly for a while. The hosta will come back next spring as gorgeous as ever, but it’s not going to look pretty until then.
How to Divide Hosta
There are a couple of ways to divide hosta, but this is my preferred method. Lift the clump and brush away as much soil as possible. The rinse away all of the remaining soil. With the soil gone, it’s easier to tease apart the roots. I try to have a minimum of 3 eyes per division. Generally if hosta are sold ‘bare root’ they are sold in 2-3 eye divisions so I figure that must be a good number.
Here’s a closer look at one division where you can clearly see there are 3 eyes or shoots.
The other method is to dig up the root ball and then using a sharp shovel or a hori hori knife, cut through the clump to divide into as many divisions as you decide on.
A hori hori knife is an amazing tool to have for this purpose. It’s the gardener’s equivalent of a multi-tool. You can use it as a narrow shovel, and it has measurements marked on the blade so you know how deep your hole is. One side of the blade is serrated, the other has a knife edge. It’s perfect for dividing root balls. If you decide to get one invest in a good one and make sure it’s made in Japan before buying.
Transplanting Divided Hosta
These hosta happened to be going to a new bed. I prepped it the same as usual, layers of newspaper underneath to block weeds and a thick layer of compost on top. The bed is deep enough to allow the hosta room to grow.
Please don’t do those skinny skimpy beds around your tree! They should be at a minimum 18-24 inches from the trunk to the edge and more for larger plants. Anything less than that you should just mulch and skip the plants. Your plant should be far enough from the trunk that it has room to grow.
When planting hosta, the root is always the center. It grows all the way around, so if you have the root crammed up against a tree trunk or a fence it’s not going to grow right and it won’t look very good.
Here is the same hosta today. I divided and transplanted these on June 9th, so if I’m doing the math right, this is 17 days later. You can see not all the leaves are standing up.
But that’s fine because when you look closer you can see the new growth coming up from the center of the plant.
So that’s it! See how easy it is to divide hosta?
I wanted to divide my hostas so a friend and a son could have some. I dug up one of a dozen–and there is NO WAY to divide that very dense root ball to make it look as nice and lovely as yours. I divided it with a shovel, and there are probably a couple dozen (eyes) in each division (four divisions). The edges of the roots where the shovel went down are sliced. Will the inner plants still grow?
You’ll be amazed at how soon each of those divisions turn into a new clump. If the eyes have just started to grow it will fill in as if nothing happened. If the leaves are already up it might look a little awkward this year but will completely recover its tidy shape for next year.