
Several of the fifty or so species of Yucca are difficult to distinguish from similar species. Some are varieties of species, rather than distinct species. Some are naturally occurring hybrids. Curve leaf yucca, Yucca recurvifolia, is supposedly a naturally occurring variety of mound lily, Yucca gloriosa var. recurvifolia (or tristis). Alternatively, it could be a hybrid.
As if that is not confusing enough, its physical characteristics are variable. Foliar color is typically grayish, but might be simple olive drab like that of many other species of Yucca. Its typically pliable evergreen leaves that curve downward as they mature can be almost as rigid as those of common mound lily. Stout but upright trunks may or may not develop.
Curve leaf yucca is remarkably resilient. Actually, unwanted specimens can be difficult to eradicate. Small bits of rhizome can generate pups for many years after the removal of a primary plant. Occasional watering is appreciated through the warmest summer weather, but may not be necessary. Old colonies can get ten feet tall, and occupy significant area, but quite slowly.

This is why I do not bother growing greens in the garden just yet. Wild radish grows here wild; and there is way too much of it. Most but not all of it gets mown in meadows or cut down with weed whackers on the edges of roadways. There is no need to cut down that which is out of the way. Besides, we could not cut it all even if we wanted to. There is wild turnip and mustard too. All are prolifically naturalized and invasive exotic species.
Generally, that is how they are. Almost all perennial pea flowers bloom with the same bright purplish pink color of the bloom in the picture below. That is, of course, before their pods develop, but you get the point. We sort of know what to expect from them.





Even within its native range, blue dawn flower, Ipomoea indica, can be a problem. There are not many other plants in some coastal regions of Peru that can avoid getting overwhelmed by the aggressive wiry vines. These vines grow roots where they touch soil, so can spread indefinitely over the ground. Vines that succumb to frost over winter regenerate as if nothing ever happened.
A well designed landscape should be an asset, not a liability. It should beautify and enhance the function of outdoor space, while harmonizing with associated indoor spaces. In order to continually do so, even a very well designed landscape requires maintenance so that it does not become so overgrown that it becomes unsightly and obstructive.
