Ask Mr. Smarty Plants

Sounds like the only additional help you could give all 3 of your Yucca filamentosa (Adam's needle) would be to get in your time machine, go back and plant them differently, with good drainage arranged for in advance. No time machine? These plants are tough and with some more attention to keeping the roots from getting so wet, should do just fine.

The real diagnosis here is transplant shock. You took 3 mature plants, the species of which is usually more fitted to deserts, and planted them, when they were already mature, in wet soil. Yuccas are, however, uniquely suited to this kind of mistake, because they propagate with great determination. In fact, once you have a yucca, you HAVE it, if you know what I mean. You can dig a yucca root completely out and throw it away, and in a few months you will have little plantlets coming up in a circle around the location of the original root. They can propagate from seeds, if there are yucca moths in the neighborhood to pollinate them, but they aggressively reproduce from even the smallest scraps of root.

In future, if you wish to plant more, for instance, offshoots of the existing plants, prepare the hole to be more desert-like. You can't do much about the rain (and in Austin we can't seem to do much about the lack of it) but you can make sure that the water that hits the soil around the plant drains away quickly. The use of sand in the new hole was good, adding some decomposed granite would help even more. But starting out with the right kind of hole and amendments is the best plan of all.

Be sure and follow this plant link Yucca filamentosa (Adam's needle) to our webpage on the plant for more information. In addition, here is an excellent article on How to Plant a Yucca Plant. And, finally, from Floridata where it's usually too wet, too, here is an article on Yucca filamentosa.