How To Keep Moon Cactuses Alive For As Long As Possible + Propagation Tips

Any succulent fan will love the look of the bright, colorful moon cactus.

Interestingly enough, these unique plants don't produce their own chlorophyll, and they have to be "grafted" onto another plant to survive. So when you spot a moon cactus in the store, it's actually two plants in one.

Moon cactus, also known as Gymnocalycium mihanovichii or Hibotan cactus, is native to South American deserts in places like Brazil and Argentina.

It's a grafted cactus, which, according to Debra Lee Baldwin, author of Succulents Simplified, means a plant that has been attached to a host plant.

The top part of a moon plant is unable to photosynthesize, aka make energy from sunlight, due to a lack of chlorophyll.

"Grafting enables its vascular system to obtain nutrients from a host plant," Baldwin explains, adding that "grafted cactuses tend to be less hardy than those that grow on their own roots, but sometimes grafting is the only way to keep a desirable specimen going."

Because these plants have a hard time living on their own, Baldwin notes they typically last for only six months to a year—if you're lucky. "It's sort of set up for failure," she tells mbg.

For your moon cactus to last, they need to be kept indoors, whether in a greenhouse situation or near a bright window inside. If you try to keep it outside, it needs protection from the sun.

"Keep in bright shade with one or two hours of slanted sunlight (morning or afternoon) daily, depending on where you live," Baldwin suggests.

If you live somewhere with intense sunlight, she adds, you'll need to make sure your moon cactus doesn't get sunburn—yes, really. If your plant is showing beige patches, it's likely sunburned.

The lighting factor can be tricky since the top part is sensitive to light, while the host cactus still requires it.

Moon cactuses also don't do well in the cold, as you'd probably imagine, and need to be kept in a space that's relatively warm and definitely protected from frost, Baldwin adds.

Like most cactuses and succulents, moon cactuses aren't the thirstiest of plants and don't require too much watering. You should only be watering them about every two weeks, allowing the soil to dry between waterings, Baldwin explains.

During the winter months, your moon cactus may need to be watered even less frequently, especially if it's over a year old. This succulent watering guide will tell you how to discern when your little guy is thirsty.

The colorful part of some (but not all) moon cactuses will produce little offshoots that can be propagated. These can be grafted onto another cactus or "rootstock," such as Cereus peruvianus, Hylocereus trigonus, or Trichocereus spachianus.

To do this, use a clean knife to cut off the top piece (or "scion") you want to propagate, and then, using a healthy, rooted cactus (such as any of the aforementioned varieties), cut off the top so it's only about a few inches tall. Set the offshoot on the top of your new rootstock where it was cut.

Moon cactuses are gorgeous to look at and relatively easy to care for, but because of their short life spans and lack of chlorophyll, they're known to be heartbreakers.