Deltoid-Leaved Dew Plant
ROYAL HORTICULTURAL SOCIETY AWARD OF GARDEN MERIT
Synonyms of Oscularia deltoides (5) (Updated on 2-9-21): Lampranthus deltoides (L.) Glen ex Wijnands, Mesembryanthemum deltatum (Schwantes) Maire & Weiller, Mesembryanthemum deltoides L., Mesembryanthemum muricatum Haw., Oscularia deltata Schwantes
Oscularia deltoides (L.) Schwantes is the correct and accepted scientific name for this plant. The genus and species were named and described by Martin Heinrich Gustav Schwantes in Möller’s Deutsche Gärtn.-Zeitung in 1927. The species was named and described as Mesembryanthemum deltoides by Carl von Linnaeus in the first volume of the first edition of Species Plantarum in 1753.
As of 2-9-21 when I last updated this page, Plants of the World Online by Kew still lists 23 accepted species of Oscularia. Botanists have come a long way because the 2013 version of The Plant List only named 2 accepted species and 32 unresolved names. It listed Oscularia deltoids as a synonym of Lampranthus deltoides, which is, of course, now a synonym of Oscularia deltoides according to Plants of the World Online. The Lampranthus genus is still an accepted genus with 124 species… Oscularia is a member of the plant family Aizoaceae with 119 genera. Those numbers could change as updates are made.
THERE ARE A FEW LINKS AT THE BOTTOM OF THE PAGE FOR FURTHER READING.
I found this Oscularia deltoides, unlabeled, from Mast’s Greenhouse on May 5, 2018. My sister and niece had come down from the city to go plant shopping at the four local Amish greenhouses. While most of the plants at the Amish greenhouses are labeled, many of their cactus and succulents are not. No matter how many times I tell myself I am not going to buy unlabeled plants, I always do. This time, I could not pass up such a neat looking plant. I figured surely I could put it on the Facebook group called Succulent Infatuation and one of the members would know. It took 12 minutes for a member to give me the name after I posted the photo.
Origin: Southwestern Cape in South Africa.
Zones: USDA Zones 8b-11 (15 to 40° F).
Size: Around 6″ tall, mat-forming.
Light: Sun to part shade, depending on the season.
Soil: Very well-draining. Good quality potting soil amended pumice (50/50) or additional perlite and chicken grit (2-1-1).
Water: Average during the growing period, less (if any) during the winter.
There are many cactus and succulent potting soil recipes online that can get somewhat elaborate. Most cactus and succulent enthusiasts recommend using a loam-based mix but I haven’t found any locally. Maybe I should try dirt from the back yard. I used 2 parts Miracle Grow or Schultz Potting Soil amended with an additional 1 part pumice and 1 part chicken grit for several years. I switched to using 1 part potting soil and 1 part pumice in 2018 and I have had favorable results. I re-pot any time of the year if necessary, but mainly do it in the fall and winter months because a peat-based mix gets very hard when not watering on a regular basis. Since I rarely water the cactus and succulents once I bring them inside for the winter their sil gets very hard. Re-potting and adding a new potting mixture in the fall keeps their soil loose and airy over the winter months.
After twelve days, the Oscularia deltoides is still kicking.
It seemed to have a growth spurt but it seems to be growing to one side… It also needs to be in a different pot.
I decided to put it in a larger pot and straighten it up somewhat on June 30. It is doing really well and is definitely an interesting plant.
I moved most of my potted plants to the front and back porch on July 4 after the Japanese Beetle invasion where they had been. I put the Oscularia deltoides on the back porch then later moved it to the front porch where it would have some shade.
The Oscularia deltoides is a very nice looking plant with reddish stems with short, triangular, toothed, silver-blue leaves. They produce pinkish-purple flowers
Very low maintenance plant that spreads out forming a nice mat and will cascade over walls and pots.
They need light to part shade during the heat of the summer and more light during the rest of the year.
Oscularia deltoides are native to winter rainfall areas of South Africa, therefore, it tolerates very dry periods during the summer. In cultivation, they prefer regular watering spring through fall, but less during the winter. They do grow the best when watered regularly and the right light. I guess you just have to experiment somewhat.
According to Llifle (Encyclopedia of Living Forms), this species is frost hardy and grows well where the winters are cold… Well, there is a limit. Dave’s Garden says USDA zones 8b-11.
By the time I moved the plants inside in October the Oscularia deltoides was beginning to have some difficulty. It died not long after that. Hopefully, I will find another one because I really liked this plant.
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.