My Adam's needle yucca flowered for the first time this year. It does not look like it is going to grow in that area anymore, but the leaves are still green. Should I cut it back at all?
You need only prune out the spent flower stalks. Aside from removing old leaves and flower stalks, yuccas do not require any pruning. If you need to prune to control height, prune in the spring before new growth begins. If the plant is well established, you can cut it off at any height (including ground level), and it will begin two to four new stems from right below your cut.