Growing Succulents in the Desert Column
Fall is the Time to Shop for Adeniums by Mark Dimmitt
(This article may only be reprinted with the author's permission.)
Although there are about 11 species of Adenium from different climates all over Africa and southern Arabia, there is a general growth pattern in cultivation. The great majority of plants that are sold commercially are obesum or its hybrids. The parent species grow in equatorial Africa, where they have no obligatory dormant season they will grow year round as long as they are kept warm and moist. These plants do most of their vegetative growth in the hot summer months, when they flower little or not at all. The flowering season begins when days shorten and the temperatures begin to drop; in Tucson that’s in September or early October. If they are kept under tropical conditions (wintered in a greenhouse or a sunny window where the nights don’t fall below 50° F), they will continue to flower all the way to the following spring (April or May). So if you buy a plant now, you can expect to enjoy their beautiful flowers for 8 or 9 months (Figure 1).
If you want a really superior hybrid, shop in a desert nursery in July or August. Any plant that is in good flower during the peak summer heat will probably flower year round (if it was grown here, not recently imported). Some obesum cultivars and hybrids with swazicum and crispum often flower year round.
Some nearly everblooming adeniums:
- ‘Crimson Star’
- ‘Daeng Siam’
- ‘Evelyn Marie’
- ‘All Year Prosperity’
- ‘Harry Potter’
- ‘Beauty of Taiwan’
- ‘Twinkling Moonlight’
- ‘Home Run’
- ‘Pink Elegance’
- ‘Candy Stripes’
- Keep in mind that smaller plants have fewer flowers over a shorter season. The display gets better as the plant matures.
- If you can't keep the plants warm over the winter, it is critical that you dry them out for the cool period. The best way to kill an adenium is to give it cold wet feet. Adeniums adapt well to a winter rest. The only downside is that you will lose much of the winter flowering season. Also, much of the caudex growth occurs in fall and winter.
- All the species other than obesum have an obligatory winter dormancy. They must be dried out and allowed to rest for a few weeks to a few months depending on the species and the winter temperatures. Therefore it's important to know what kind you have. Cultural instructions can be found in a Cactus and Succulent Journal article, which is also posted on TCSS's Adenium Website . More detailed and up to date instructions are contained in the book Adenium: Sculptural Elegance, Floral Extravagance by Tucson authors Mark Dimmitt, Gene Joseph, and David Palzkill.