Don't forget caudiciforms

[Sallyd]

I love cactus and caudiciforms. The wierder the better. The big caudex with the beautiful flowers is such a study in contract. I think the Desert Rose is one of my favorites because it flowers so much.

[Dave]

I found some information on the web to educate others what Caudiciforms are. Hope this helps!

To those that do not know what a caudiciform is, I will say that it is not really a true "biological" term. It is a descriptive term for those plants that have been forced to live in extremely unfavorable climates, deserts, etc. They have adopted various measures to survive long periods of drought. They hide beneath the sand and send out vegetation only after it has rained. Or they develop "trunks", caudices (or caudexes) which store whatever it takes to survive long periods of deprivation. They often take on bizarre shapes. They often have beautiful flowers.

Because Caudiciforms occur in so many families, it’s difficult to make any sort of intelligent, general comment as to the proper methods of cultivation. What works for one plant may simply kill another. So I will attempt to make some simple observations here, and hopefully they will work out for you.


Dormancy-First, it’s important to know when your plant observes dormancy, so that appropriate watering and temperature can be observed. The vast majority of Caudiciforms are summer growing/ winter dormant, but there are exceptions to this. Do some research and make sure you know what to expect.
Of course, when plants are dormant and leafless, they cease to transpire and so have little use for water during this time. However, it’s always good to give your plants a light drink of water every couple weeks to insure that the roots are healthy. Summer dormant plants may need this drink much more often as plants and soil desiccate much more quickly in the heat.

Soil Well, each species will be different here. Many of the woodier Caudiciforms will like a somewhat heavier soil, while many of the more succulent plants will prefer a more average and well drained succulent mix. Some Caudiciform enthusiasts use entirely mineral based soils, ranging in composition from Turface-type materials, to higher fired, porous clay products such as ‘hydrocks’, to gravel or coarse sand/grit. For most large, established specimen, I personally prefer to have the caudex sitting on an inch or two of dressing material like hydrocks or gravel, but the roots are usually in a well drained mix. This fairly well simulates the habitat of many of these plants, in which the soil surface is dry and extremely well drained, while the root zone tends to retain a bit more moisture. Sometimes this root zone may only consist of an inch or two of soil in the bottom of the pot, but often it’s more. This strategy is also helpful in that if your plants roots begin to rot, it’s often still possible to pull the caudex, remove any infected roots, and re-establish the plants.
That said, most younger Caudiciforms can simply be grown in regular potting soil, with the addition of a generous amount of perlite or pumice. When the caudex becomes about fist sized, then it's time to decide how you want to treat it in it's adult life.

Watering- As Caudiciforms are designed to withstand long periods without water, they tend to be more tolerant of drought than over watering. This is especially true of specimen sized plants, while smaller plants can often be very thirsty in their active season. Basically, the best I can say here is to pay attention. If your plants seem happy with the amount of water you’re giving them, then continue. If not, then do something different. I can say that plants should not become shriveled and desiccated, even in the dormant season. If this is happening, it usually means that your plant needs some water. Like most succulents, it’s simply best to keep the soil at least slightly damp during the growing season. This insures the health of the roots, and that the plants will be capable of growing.
Fertilizer- use a high phosphorous- low nitrogen fertilizer, and alternate this with a low nitrogen- average phosphorous fertilizer. This will encourage root and caudex growth. We have also found silicon supplements to be helpful once or twice a season.

Lighting- This will vary widely from plant to plant, but common sense will usually give an answer pretty quickly. For example, if your plant is normally a 40 foot tree in habitat, then the lighting of an east window will usually not be sufficient, though this plant might do very well on your patio in full sun. Another example, if your plant is normally only a foot or two tall, but naturally grows between larger scrub brush, then part sun in any direction would probably be ok, South probably being the best. If however, the plant grew under the bushes, then an East or broken sun exposure would probably be best. It just requires some thought.