In clearing my garden this weekend I noticed a branch of my hydrangea touching the ground. When I tried to pick it up to examine it, I noticed it had actually rooted in the ground!

I cut it at the base of the plant, brought it inside and put the rooted part in water in a sunny window... now I'm wondering if it could possibly be true that I could plant this in the ground and get a new plant! :) My hydrangea are my favorite features in our garden (they were here when we moved in last year!)

Wondering if you have advice for me on the following:
-- Is it ok to just leave this rooted branch in a vase until it is warm enough outside to plant?
-- Any advice on timing of planting it?
-- Any advice on location or other tips to help me succeed?
-- Any sense of what to expect for first year growth?

As an FYI, there are a few buds on the branch.

Thanks for any advice! As I start to get more into caring for my garden this season, I'm looking forward to diving into the forums.