I've never tried valerian in a container but I don't see why it couldn't work. I do, however, find valerian short-lived in my garden but it has a way of spreading its seed and popping up where it wants, no matter what you try to tell it.

FataMorgana

I suggest something fairly large. Mine gets 4 or 5 feet tall. Even when young it tends to be fairly thirsty in a pot, especially one too small.

F. DeBaggio

If you have more than one plant, a better option might be to plant some in each location. Then they can reseed themselves. In a good location, you could eventually have more, if there is a way to provide adequate moisture. I assume you have checked into zonal preferences already....

When you say 'valerian' are you growing common valerian (Valeriana officinalis) or red valerian (Centranthus ruber)? They require different growing conditions so that might affect the outcome in pots. Red valerian likes very sharp drainage and self seeds in cliffs and old walls. It can grow into a sizable plant a good yard high and wide. Common valerian likes things a bit damper and is not as large. I'm not sure how either would fare in Arizona. They both thrive in Britain so that tells you the climate they like. If it were me I would go with eibren's suggestion of a plant in each location.

Mine is the common Valerian. I can plant it in Colorado and it will, I imagine, survive fine -- most of my herbs are very nice. However, in Arizona, I think it would work as long as the watering sytem works during the summer months! I thought contaier growing would be best in Colorado, as I can put i on the patio and out of reach of deer. Thanks!