I spotted this topiary in the summer at a garden center here in Chicago that I visited for the first time. It is a simple sphere shape stuffed with moss and planted with jade plant cuttings. Crassula ovata is an evergreen succulent plant that is a very popular houseplant grown around the world. When given plenty of light the jade green leaves develop a red tint around the edge and with good care they flower small white or pink flowers. Most of the time it is grown as a tree or several stems are grown in a pot resulting in a shrub-like plant. Seeing this plant being grown in a ball topiary form was a bit of a surprise because I've only seen it grown as a tree or shrub and thought this was pretty ingenious.
This succulent like many others can be grown from a single leaf or a bunch of cuttings from a larger plant. If you've never done it before see my post Echeveria 'Black Prince' propagation where I posted pictures of new plants growing from single leaves of a succulent plant. This jade plant ball topiary will need a lot of pinching back because this plant can grow very large but this is a good way to grow some of your cuttings if you don't like wasting plants or need to keep your plant up and away from kids or pets.