Did the tree leaf out as usual in spring and then lose the leaves? Or did they simply fail to appear this spring, leaving a dearth of maroon foliage? If it's the latter, it could be winter damage (although this is more common on the green varieties, from my experience). The fact that you're seeing green leaves appearing on the stem might mean the tree is reverting to its parent rootstock. Remove these leaves so that part of the plant doesn't compete with the maroon cultivar you prefer to grow. Try to lessen the stress on the tree with part shade, ample water, a mulch of shredded leaves, and a fertilizer for trees and shrubs applied before July.
Luke Miller, editor
Garden Ideas & Outdoor Living magazine