Tucson Cactus and Succulent Society Home
Events Calendar
Cactus Rescue
The TCSS Events Email List
School and Research Grant Programs
Member C&S Businesses
Pima Prickly Park
Tucson Plant Info
C&S Plants Database
Native C&S Plants
Sonoran Conference
Contact Us

Members-only Facebook

Public Facebook

Rescue Cacti for Sale
  Tucson Cactus and Succulent Society

Growing in the Desert Column

(List of Growing in the Desert columns)

Winter-Blooming Pachypodiums

by Mark Dimmitt

Photos by Mark Dimmitt unless noted

(This article may only be reprinted with the author's permission.)

This series is devoted to featuring succulents and other xerophytes that are well adapted to the desert climate of southern Arizona. It also tends to favor unusual species that are not often found in collections. Even though we are blessed with usually mild winters and plenty of sunshine, there are rather few succulents that put on a good flower show in winter. Here are two pachypodiums that will brighten any greenhouse or sunny windowsill.

Pachypodium decaryi (Figure 1) is rare in cultivation, probably because it is very slow growing. The specimen in the photo is in a 14-inch pot and stands about three feet tall at 31 years old. With age it develops a modest caudex, topped with a few somewhat spiny stems. In summer the stems are tipped with large Plumeria-like leaves. Foliage is shed in fall, then in winter the bare stems produce large pure white flowers for about two months (Figure 2). The photo was taken in late January, about halfway through the flowering season.

This species likes ample water in summer, and should be kept dry in winter. It is a bit sensitive to extreme summer heat; I keep my plants under a mesquite tree from April through October. Protect it from frost in winter. It can tolerate low 20s under a roof and covered with a blanket.

Pachypodium brevicaule is a stunning dwarf, essentially stemless species that looks much like a monstrose potato. Many people find it difficult to grow; I have never been able to keep one alive for more than a couple of years. Pachypodium densiflorum is a spiny shrub that reaches about two feet tall and wide. Both species are prone to rot in high summer heat. Hybrids between the two are much easier to grow. The plant in Figure 3 is a five-year-old P. brevicaule X (P. brevicaule X P. densiflorum), making it ¾ P. brevicaule. It looks like a supercompact P. densiflorum. Like P. decaryi, it is winter-deciduous and -flowering. The brilliant yellow flowers are borne on nearly every stem in January and February (Figure 4).

Culture of this hybrid is about the same as for P. decaryi, except that I water more sparingly in summer. It has a small root system that doesn’t draw much water.

List of Growing in the Desert columns