The hostas are ready to be split and moved, but is the garden ready to accept them?
The best time to divide these plants is when they push up their tight shoots before they unfurl. For smaller plants I'll lift the whole thing and cut it in half or quarters depending on the size. For larger ones I'll just cut what I want from the sides. This job can be done anytime during the spring, but it looks better to do it before the plants get too far along.
If the soil is too wet though, gardeners must wait. I've dug some transplanting holes and found parts of my garden to be dry enough to work. If the dirt sticks to the shovel don't dig.
You don't want to destroy the soil structure. Turning over soil that's too wet will complicate gardening in that area the rest of the season. It creates clumps which will dry into bricks.
Like comedy, timing is everything when it comes to planting. I love expanding the garden by moving extra pieces of hostas to other areas. When you wait for the right day, you'll be sure to succeed.