I would not try to move alliums "in the green" (meaning when they are up and growing. The risk of breaking off the stem/foliage–which is what will feed the underlying bulb as it grows and also as it withers naturally while still connected to the bulb–is too great. The architecture of your tall alliums just makes this operation too risky, and they will be even more unhappy if severed from their foodsource. As for the browning foliage, this is typical of many of the big alliums…the leaves don’t even look great by the time the flowers are happening, in some cases. That’s why alliums are best grown with a good companion plant "at their feet"–I like the perennial geraniums (like G. macrorrhizum, for example) as a concealer of this allium handicap. It is probably very dry where the tree used to be, and bulbs need moisture in their active growing phases to plump up (and then need to be drier late in the season) so perhaps you can help them along with a good, deep drink this spring and until they start to die back. Bulbs can also be fed when the green get up and growing–I feed my garlic (an allium cousin) when the greens are getting started in the spring. Best to mark them carefully and move them in fall, I think, or very early before they have much topgrowth next spring (I prefer fall). I liked this question so much I am going to make it a post on the blog, perhaps with more information about moving bulbs in general (once I have another cup of tea!). Thanks. M.