Growing Adenium Plants

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Posted by @drdawg on
Although the Adenium ("Desert Rose") has all the looks of a succulent, with a water-reservoir trunk and root form, it is not grown the same way as a typical succulent.

The Adenium is of the plant family Apocynaceae, also called the Dogbane Family. This family consists of approximately 2000 species, and two well-known species are the Pachypodium "Elephant's Foot Plant" and the Plumeria. The common name of the Adenium is "Desert Rose." Adenium is a monotypic genus (only a single species in the genus), and the species is Adenium obesum. There are at least six subspecies. The flowers range from white to pink to red, and mixes of these three colors on a single flower are common. With hybridization, there are now other colors available, including yellow and very dark purple (almost black). The plants are spineless. The sap of the Adenium consists of cardiac glycosides, and that sap has long been used to coat poison arrows. Needless to say, this sap is not human or pet friendly. You certainly want to wash your hands if this sap comes into contact with your skin.

The Adenium hails from Africa and an island in the Indian Ocean, Socotra. Socotra is part of Yemen and is near the Horn of Africa. The island of Socotra is interesting because it has been isolated for so long. It is said that one-third of its plants are found nowhere else on the planet. The island is often called the "Galapagos of the Indian Ocean." So, not only do you get interesting plant-forms and beautiful flowers when growing these plants, you also get a glimpse of what plants were like millions of years ago.

Succulents are typically grown in very open, very well-draining soil. This medium is often as much sand and rock as it is soil. The consensus of folks that grow the Adenium successfully says that Adenium does in fact need to grow in a well-draining soil medium, but not one based on a "cactus mix" of sand, gravel, and peat moss. Every grower seems to have his own favorite mix, but for me at least, I am using a mix that is well-suited for growing terrestrial orchids. My mix is (roughly) 25% milled sphagnum moss, 25% Black Kow, 25% coarse perlite, and 25% cypress mulch or medium Douglas fir bark. This mix will drain exceptionally well and at the same time hold moisture. Adenium seem to grow best when they have constant moisture yet never have "wet-feet."

Though growing from seed is the most popular way to propagate these plants, plants grown from seed are generally not going to be true to the seed-pod parent. Grafting is often done to produce specific (true) plant and flower form/color. For me at least, Adenium seeds were easily and quickly germinated in seed-starting media, similar to how I start most vegetable seeds. Germination occured in 7-14 days. The seeds were sown in late May and that was in a 50% shaded greenhouse with lots of light, warmth, humidity, and air-movement. After germination, those "baby" plants were grown for another 2-4 weeks in two community trays and then potted up in individual 3-4" pots. I used clay pots for that first potting (again, my thought was that these are grown as succulents), but the consensus is that plastic pots are better suited for Adenium so that moisture can be better maintained. Those newly potted plants continued to be grown in the greenhouse for 2-3 weeks and then were all put outside on a bench. They got dappled sunlight through oak trees during the morning and early afternoon, but got full sun from about 3:00 PM until sunset. The plants remained on the bench until they were brought inside the solarium in November.

Adenium are called caudiciform plants and are grown as much for their trunk/root appearance as for their beautiful flowers. My plants are only seven months old, and though they are forming a swollen lower trunk, the roots are still quite fine. Only a few of my 18 plants had a noticeable tap-root, and I cut those tap-roots when I recently re-potted into the 4" plastic air-cone pots. I just want to see whether there is a difference in their caudex-form without the tap-root.

These tropical, succulent plants will not take freezes. During the fall and winter months the Adenium will grow in my solarium. The temperature there never falls below 62F. I have tried to keep the soil slightly moist at all times, but human nature being what it is, and with so many plants to tend, sometimes I found that the soil got pretty dry. The Adenium all seemed to do fine through my (sometimes) neglect. I did find (by accident) that Adenium leaves don't like to be subjected to other leaves resting on them. I also discovered that my homemade insecticidal solution (1 pint 409, 1 pint rubbing alcohol, and 3 quarts water) was not well-tolerated by the Adenium leaves. Both touching and insecticide caused brown spots to form on those leaves. Though the plants may be tough, the leaves appear to be sensitive.

Below are pictures taken of my Adenium plants at 2 months, 3 months, and 7 months. There is also a recent picture of my "Green Giant".

Thumb of 2016-01-07/drdawg/3760fc Two-month-old plants with the "Green Giant" in the upper left-hand corner

Thumb of 2016-01-07/drdawg/6bdce5 Thumb of 2016-01-07/drdawg/c6cd15 Three-month-old plants with the "Green Giant" in the center


Thumb of 2016-01-07/drdawg/fd058d Thumb of 2016-01-07/drdawg/6aa9bd Thumb of 2016-01-07/drdawg/b02e31 Seven-month-old plants before repotting. The "Green Giant" is the center plant and is also captured in the last photo.

 
Comments and Discussion
Thread Title Last Reply Replies
Multiple adeniums in one pot by Alia2020 Apr 20, 2020 1:04 PM 2
How to care for adenium by Hanishahani Nov 5, 2017 6:25 PM 0
When grafting a desert rose by djnonthecree May 6, 2017 5:53 AM 1
Welcome to the Adenium World by Rainbow Feb 22, 2017 2:26 PM 20
Where do you get seeds? by SarasotaPatty Mar 28, 2016 7:48 AM 6
Untitled by donnabking Mar 6, 2016 11:47 AM 3

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