x Alworthia ‘Black Gem’

Alworthia ‘Black Gem’ after I brought it home on 5-9-19, #570-1.

Alworthia ‘Black Gem’

Aloe speciosa x Haworthia cymbiformis

AL-OH spee-see-OH-suh x ha-WORTH-ee-a  sim-BIH-for-miss

Alworthia ‘Black Gem’ is a bigeneric or intergeneric hybrid cross between Aloe speciosa and Haworthia cymbiformis.

The scientific name x Alworthia G.D.Rowley was named and described by Gordon Douglas Rowley in the National Cactus and Succulent Journal in 1973.

Aloe speciosa Baker is the accepted scientific name of one parent of xAlworthia ‘Black Gem’. It was named and described as such by John Gilbert Baker in Journal of the Linnean Society in 1880.

Haworthia cymbiformis (Haw.) Duval is the accepted scientific name of the other parent. It was named and described as such by Henri August Duval in Plantae Succulentae, in Horto Alenconio in 1809. It was first named and described as Aloe cymbiformis by Adrian Hardy Haworth in Transactions of the Linnean Society in 1804.

Alworthia ‘Black Gem’ on 5-9-19, #570-2.

I brought this x Alworthia ‘Black Gem’ home from Wildwood Greenhouse on May 9, 2019. It was unlabeled so I posted photos to the Facebook group called Succulent Infatuation. I usually get a pretty fast response and it is much better than trying to figure it out. Within no time, a member suggested it was a xAlworthia ‘Black Gem’. I did a little research on the name and I think she hit the nail right on the head but we shall see. If I find out this is not an x Alworthia ‘Black Gem’ I will change the name.

The cluster measures approximately 3 1/2” tall x 6 1/8” at the widest point. There are three rosettes plus two newer offsets in the pot. The pot measures 3 7/8” tall x 4 1/2” diameter pot.

Alworthia ‘Black Gem’ on 6-16-19, #591-4.

The x Alworthia ‘Black Gem’ is still doing fine on the front porch. It’s a little hard to describe the light there, but I think the succulents get plenty. I just have to remember to water since there is a roof overhead.

x Alworthia ‘Black Gem’ on 7-15-19, #601-4.

The x Alworthia ‘Black Gem’ is enjoying itself on the front porch.

x Alworthia ‘Black Gem’ at 4 1/2″ tall x 8″ wide on 10-11-19, #639-9.

I had to move the plants inside for the winter on October 11 because an “F” was in the forecast. This has proven to be a great plant so far and measured 4 1/2″ tall x 8″ wide when I moved the plants inside. I think it will be quite a clumper…

x Alworthia ‘Black Gem’ on 11-13-19, #649-3.

I decided to put the x Alworthia ‘Black Gem’ and several other cactus and succulents in larger pots after I brought them inside for the winter. I think fall is a good time to repot so their soil will be nice and loose for the winter.


x Alworthia ‘Black Gem’ at 5 3/4″ tall x 10″ wide on 10-15-20, #747-11.

We made it through the summer with flying colors and this plant looks great! I had to move the plants inside for the winter on 10-15-20 because an “F” was in the forecast. This plant measured 5 3/4″tall x 10″ wide. So, it is growing well.


x Alworthia ‘Black Gem’ at 5 1/2″ tall x 11 1/2″ wide on 8-17-21, #826-12.

LOOKING GOOD! The x Alworthia ‘Black Gem’ has done well over the summer despite a small bout with mealybugs during the winter. The plant already has quite a few dead leaves which I had to remove so no bugs could hid in them. I cleaned its leaves and sprayed it several times but I will still need to watch it over the winter. Eggs could be lurking still… I normally measure the plants the I bring them in for the winter, but I am getting an early start on the plants on the front porch. On August 17, it measured 5 1/2″ tall x 11 1/2″ wide. That is 1/2″ shorter than last October and 1 1/2″ wider.

There is very little information online about this plant so hopefully, I can contribute a little experience as time goes by. So far, I really like the x Alworthia ‘Black Gem’.

Family: Asphodelaceae
Origin: Hybrid. Parents are from South Africa
Zones: USDA Zones 9b-11 (25-40° F)
Size: About 6” tall
*Light: Light to part shade
**Soil: Very well-draining potting mix. I used 2 parts Miracle Grow Potting Soil with 1 part additional perlite and 1 part chicken grit for many years. I started using a 50/50 mix of Miracle Grow Potting Soil and pumice in 2018 and it works very well. 
***Water: Regular watering during the summer but sparingly during the winter.

Aloe and their cousins are some of my favorite plants. They are very easy to keep as companions as long as you follow a few basic rules. Even so, there have been a few I have had ups and downs with but eventually, we get it figured out, or at least we agree to disagree. Normally, it has something to do with water. You can’t lump all succulents in the same category when it comes to care because many are very unique in their preferences…

Aloe and their cousins are considered a summer dormant/winter growing species but for me, they seem to grow pretty much year-round. I read where Aloe hybrids don’t go dormant and whether they are summer or winter dormant depends on where the species are native. Personally, I think most Aloe will grow year-round if given the opportunity but I am no expert. For me, I think they do most of their growing while outside from May through mid-October, but most show no sign of being dormant while inside for the winter. Their growth does slow down while inside over the winter and I pretty much withhold their watering to a little once a month if necessary. 

*LIGHT: Most information online says Aloe “prefer” full sun but I keep mine on a west-facing front porch during the summer. There is a roof and two maple trees in the front yard that provide shade part of the day, but they still receive a few hours of direct sun. I guess you would call this “light shade”. The reason I keep them on the front porch instead of the back deck where the cactus are is because I don’t like their leaves to burn. Some species need bright light so their leaves won’t stretch, but not so much that their leaves burn. Of course, it all depends on your climate and you will just have to experiment. If you are keeping your Aloe inside for the winter and want them in the sun during the summer, you will have to allow them to get accustomed to brighter light gradually… From mid-October through April, sometimes into May, most of the succulents are sitting on shelves in a cool bedroom in front of a south-facing window.

**SOIL: As with any cactus and succulent, they need fast-draining soil. Some Aloe grow a massive root system and aren’t that particular about their potting soil. There are MANY recipes online for cactus and succulent potting soil and some can get pretty elaborate. Since 2018, I have been using 50% Miracle Grow Potting soil and 50% pumice that I ordered from General Pumice online. For many years I used 2 parts Miracle Grow or Schultz Potting Soil with 1 part additional perlite and 1 part chicken grit. If you are going to use sand in your mix, use a very coarse builders sand as the fine stuff fills in the air space between coarser ingredients. The idea is to have a lightweight potting mix that drains quickly and will dry out within a few days. As far as re-potting goes… If your plants are outgrowing their pots, you can re-pot any time. I usually re-pot my cactus in the fall and winter because peat-based mixes get hard when you stop watering. That way, their potting soil is nice and airy over the winter. Depending on their root system, increasing the diameter of the pot by 1/2-1” is enough once you remove the old soil from their roots. But, that depends on your plant… Not adding too much depth is more important because you don’t want damp soil below their roots which can lead to rotting… 

***WATER: I water my succulents on a regular basis during the summer but there are many times I get busy and they get neglected. Being on the front porch with a roof, they don’t get that much rain unless it blows on them. I usually give them a good soaking a few days before an “F” is in the forecast when I have to bring them inside for the winter. From mid-October through April I water my cactus and succulents very sparingly if at all. Normally, I “may” give the Aloe a little water once a month, but for most of them I don’t give water until December or January. Aloe store water in their leaves, so they can go for a long time without additional moisture. Better to be safe than sorry over the winter months… You can tell by their leaves if they need water. If they start to curl inwards along their margins then they are needing a little water. 

When you bring your new plants home from the store, you need to check their roots and the soil to see if they are wet. If so, you may want to re-pot it right away. It is advisable to re-pot them in a better potting soil more suitable for cactus and succulents. Always check for critters that may come home with the plants and keep an eye out during the winter months… 

You can read my Cactus Talk & Update and Cactus & Succulent Tips to get my opinion about growing cactus and succulents.

I hope you enjoyed this page and maybe found it useful. If you have any comments, questions or suggestions, I would like to hear from you. Please click on “like” if you visited this page. It helps us bloggers stay motivated. 🙂 You can check out the links below for further reading. The links take you directly to the genus and species of this plant.

(Aloe speciosa/Haworthia cymbiformis)
(Aloe speciosa/Haworthia cymbiformis)
(Aloe speciosa/Haworthia cymbiformis)

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