Gymnocalycium mihanovichii - Yellow Moon Cactus

We love how stunning these cacti look, catching the eyes of passersby as well as us in the shop. These cacti are grafted together, meaning each moon cactus is actually two cacti: one for the stem, to funnel water and nutrients upwards, and one at the top, to add the stunning colour and personality. This variety's bright yellow contrasts with the mid-green stem. The shape contrasts too, with the round 'moon' on the top paired with the columnar growth underneath. The stem cactus, Selenicereus undatus, grows faster than the Gymnocalycium on top, so after a few years you may notice the graft come apart. You can try to keep both parts going separately, but often the colourful cactus does not have enough chlorophyll and may die on its own (hence putting it in the graft in the first place) - the green stem will probably be perfectly content to keep growing by itself, though, so even after the graft has run its course, you can keep growing part of it.

Scientific Name
Gymnocalycium mihanovichii (Mihanovich's bare-skinned plant) and Selenicereus undatus (moon-wax plant with waves)

Was previously known as Echinocactus mihanovichii, but has been accepted and described as Gymnocalycium mihanovichii since 1922.
S. undatus was recently reclassified, so you may also see it under its old name, Hylocereus undatus.

Common Name
Moon Cactus, Lantern Cactus, Oriental Moon Cactus, Yellow Moon Cactus

Origin
These cacti are native to desert areas of South America

Light
Keep your Moon Cactus in bright, direct sun. A south- or west-facing windowsill should give it plenty of light.

Water
Let the soil totally dry out between waters; this plant is adapted to arid environments so won't appreciate being waterlogged.

Humidity
Make sure this plant isn't somewhere very damp; iot is used to arid, dry air so is happy in most household conditions.

Soil
Use a well-draining mix designed for cacti and succulents; this should be one with plenty of sand and grit in.

Food
Feed every couple of months with a weak fertiliser (or one designed for cati) in the growing season; reduce to every three months in autumn and winter.

Temperature
Likes temperatures of 18-32°C; should be on the warmer end in spring-summer and cooler but no lower than 15°C in its autumn-winter dormancy period.

Pet-safe
No, this plant is slightly poisonous, and its spikes can be painful for unsuspecting paws.

Sprouts Top Tips
Keep it somewhere bright, don't water it unless the soil has dried out, and this plant will be just fine. The stem cactus is far more successful at surviving than the top one, so even if you lode the colourful bit after a few years (grafts are not always made to last) you will have a cute green cactus to keep growing.