Gasteria or ox tongue, as they are commonly referred to, is a genus of plants endemic to Southern Africa. Their unique form and pendulous flowers have attracted enthusiastic collectors from around the world. And no wonder, as you can find a species in bloom at any time during the year.
In order to learn more regarding this unusual genus, we dive into a bit of history, learn how to grow and care for them, as well as doing some hand-pollination at home.
Gasteria in Southern Africa
During 1620-1680 the European interest in South African and Australian flora peaked, prompting many botanical expeditions. Nonetheless, it was only after the turn of the 18th century that Carl Linnaeus collected the first Gasteria specimens. These and other collected specimens made their way to Europe over the coming years. Fast forward several centuries to today’s South African botanists and we are still discovering new species.
Habitat: Gasteria occur on cliff faces and Klein Karoo shrubland. Most of the species are located in the Eastern Cape with some like Gasteria carinata extending into the Western Cape.
It is no secret that one of South Africa’s foremost botanists, Ernst van Jaarsveld (@ernstvanjaarsveld), started his career with a masters thesis on South African Gasteria. He has since gone on to publish numerous titles and curated the current succulent collection at Babylonstoren. The most recent publications include a new species registered in 2020. Gasteria visserii is the latest in a handful of species that have emerged in recent decades, begging the question: “Do we really know all of them?”
Gasteria species and hybrids
Gasteria are close enough (genetically) to Haworthia and Aloe that cross-hybridisation is possible. This has triggered a mountain of quick-growing hybrids to enter the horticultural industry, providing each homeowner with a windowsill plant. The variety of cultivars has its own following and thus sustain an industry on its own.
Not sure how to distinguish between Aloe, Haworthia and Gasteria? Dig into the post below!
What is a hybrid? A plant that has been created by two different parent species.
Some of the most sought after hybrids have come out of East Asia, specifically Japan. These include Gasteria “Silver Fuji”, Gasteria “ Isomatsu”, Gasteria ‘Ginsha Kodakara’ and Gasteria ’Sakiware’ to name but a few.
If you are like me, you opt for admiring species in lieu of hybrids. Lucky, many dedicated succulent nurseries also offer seed grown species. So if one wants to start a collection there are many to choose from.
Growth and Care
The succulent nature of Gasteria extends to their fleshy root system. In many cases, the root system is shallow and strong, allowing them to grip onto cliff faces (accessing small pockets of soil). This tells us that they do not need large amounts of water. Coastal species may be more tolerant of overwatering than Karoo or semi-desert species, but root rot remains a universal problem.
Here are some care tips:
- Use Terra cotta containers. Shallow or small containers work best with dwarf species.
- Soil needs to be very well-draining. I use 50% grit, but can be amended further to suit your climate. Indoor plants will often require more drainage than outdoor pots.
- Place in bright indirect light. Some species like Gasteria acinacifolia or Gasteria carinata can handle direct sun if exposed gradually (the leaves will turn a deep red). Most prefer dabbled sun, not deep shade. A west or east-facing window should be ideal.
- Watering: This will depend on the medium and season. They will need water year-round, but less in colder months when evaporation is lower.
- Feeding: Including bonemeal and leaf mould compost in a gritty medium should suffice. If neither is available, a balanced fertiliser seaweed fertiliser can be diluted and fed during the growing season.
- Flowering: Is species-dependant. Failure to flower might be due to low light, maturity or disease.
Propagation and hand-pollination
Gasteria have a natural tendency to produce clumps via pups or suckers at the base of the plant. Removing the pups is the easiest way to propagate. A close second is by sowing seed. The flowers are pollinated by sunbirds and sugarbirds alike but can be hand-pollinated.
Hand pollination: Attach a single strand of paintbrush fibre to a toothpick with tape. You can also use hair or a very fine paintbrush (size 1-2). Collect the pollen and transfer it to the stigma.
See the guide below to learn more about collecting succulent seed.
Germinating Gasteria seeds are fairly straightforward in my experience. It just takes around 2-3 years before the seedlings reach a size where you can pot them on. Keep this in mind when spacing the seeds. Seedling trays do not need to be very deep and make sure to keep them moist.
More reference work
I would highly recommend that collectors go the extra step of acquiring one or more reference books on species. These give you a new appreciation for the genus.
- Gasteria of Southern Africa: A new revision of a major succulent group by Ernst van Jaarsveld Illustrated addition.
- Or Register for Ernst's Succulent Workshop at Babylonstoren: Unlock the diversity of indigenous succulents on 2 June 2021 or 17 November 2021.
To explore the rest of the series on succulents scroll down and enjoy.