Aloe ferox just loves slopes. I doubt if anybody would think they are hanging. Just wanted to add the pretty scene.
Aloe hardyi blooms in winter.
plant and then it turns upwards. The small flowers are pretty, shading red with green tips. Buds are not open yet on the photo below. Aloe pendens blooms every 5-6 months.
The relative small grass-like Aloe ballii from Zimbabwe also grows hanging from cliffs. It is a very pretty aloe for a hanging basket. It grows fast and easy and blooms throughout the year. It would not fare too bad growing on flat ground except for the flower. The flower stalk is a thin soft thread hanging down and that would not function on flat ground. On the photo is an inset of the pretty flowersand on closer look you can see the flowers
PS. I have only one plant, no seeds.
Aloe ballii is hanging on a branch to the right top in a basket . . Aloe hardyii is to the right on the wall and Aloe pendens (plant colour very much like the background) is in the middle. There are a few smaller aloe types on the top of the wall and some other succulent plants. The wall is very narrow and takes up little space but a lot can be planted on it. (flowers would be pretty too).