It's worth a celebration for rooting alba. I was told many times that the only way of propagating alba is by air layering.

The alba can be kept in a container for sure, I live in Ottawa, Canada. Far colder than your zone. I am keeping an 8 feet tall Alba in a sunroom, growing like weeds and the fragrance is overwhelming. I have to prune it soon. It blooms profusely in a relatively small size. If you have a green house, it's going to love it. The only trick is the perfect drain, use clay pot if you can. Don't overwater and don't let the root gets too cold. If the mother plant has reached flowering size, I would say you are going to see flowers next winter time.

What did you do to get it rooted? I am to lazy to air layer so many twigs.

I was shocked when I saw that it had rooted. I'd heard it could only be propagated by air layering also. I just dipped the twig in rooting powder, put it in a pot covered with a plastic bag and set it on a heating mat. The kind you use for seed germination. Two months later there were roots coming from the bottom of the pot and new leaves growing.