I spent the weekend digging up plants to get ready for the Green Girls plant swap May 31, and it reaffirmed my affection for hosta. They spread a little, but in a very contained, polite way, and wait fairly patiently for you to realize that they really could benefit from dividing.
While fall is a great time to divide hosta, spring isn’t a bad time either; just make sure to keep transplanted hosta well watered to avoid heat stress and they’ll settle back in fine.
I generally dig up the entire clump, using a sturdy shovel to dig well around the plants until the root ball breaks loose, digging deep enough to avoid damaging the roots. This year I’ve been encountering some very well-rooted hosta and got in a good workout. Once you’ve got the entire plant out, try using your hands first to get the roots apart. If it’s fairly well knotted, use a spade or long trowel to help break them apart. Don’t worry if a few break off, there’s more where that came from.
Then it’s fun time, when you discover that what went into the ground as one bareroot hosta plant has now had a loaves-and-fishes-like transformation. One medium-size golden hosta plant yielded 10 generous clumps, and could have been further divided if I’d felt like repotting that many plants.
Dividing hosta every three to four years helps the plant stay healthy, and I find that if I divide the clumps, they’re less likely to become a slug playground.
So if you’re wondering what to bring to the plant swap this Saturday from 10 a.m. to noon in the park across the street from the Star Tribune building at 425 Portland Av. S., Minneapolis, take a look at your hosta and see what could stand dividing. If you’re like me, you’ll wind up keeping a few for yourself.
Just make sure to pack them in some dirt if you're digging them up before the morning of the swap or they'll be droopy and harder to swap. Here’s a link to a post from last year on other tips for getting the most out of a plant swap (note that the timing was earlier last year). And here’s a link to a video for more info on dividing hosta from the folks at Spring Hill Nursery.
Gardeners, how often do you divide your hosta? Or do you just let them slowly expand in place? Some varieties take much longer to be dividing candidates than others.