Ask 5 different people and odds are you'll get 5 different answers. Lots of people do them when the noses first break the ground since it will be quite easy to handle and not have to worry about much, if any, damage to the leaves. Personally I prefer to do my dividing in early summer, when the roots are actively growing. Most will agree though that you can divide and/or transplant them most any time of the year except for the dead of winter when the ground is frozen. It's pretty hard to kill a Hosta, unless you drown them and allow crown rot to set in....

why do they need to be divided ... hosta NEVER really need such ...

if a plant does not fit a given space... replace it with on of the other 4000 cultivars that do fit the space ...

ergo .. they need dividing .. when you need the exercise ...

now.. they might need to be moved once in a while ...

you would time that for either of these 2:

1. while completely dormant .. as they have a tendency to flop after root disturbance.. so if you do it at this point.. nothing to flop....

2. or later in the summer .... or early fall .. when they already look like heck .. and you really dont care if they look worse because of flopping...

there is a second flush of leaves in july/august.. so if a plant is moved and flops.. not long after... new leaves will come up and not be floppy, if digging and watering is proper ...

if you wish to multiply your hosta... dividing for a goal ... it can be done at any time ... but one would not be looking for a nice plant after micro dividing .... but they will be nice plants next year ...

again ... the key is how they will respond to the digging ... and how they will look afterwords .. rather than some timing which is important to the hosta ...

and while you are at it... if you dont already know.. dig one and throw it on the driveway .. and leave it there all year .... and i would bet a buck it will sprout next spring ... as long as it doesnt get fried ...

good luck
ken

Well, they have been in this spot for probably 10 or 12 years, and they are big enough now that i can divide them and make more plants for another location. Thanks for the input!
Sarah