Caudiciform plants: keeping that swollen caudex healthy

Some plants store water in the base of their stems, ending up with the bottle or tortoise shape that collectors can't resist. I read a practical guide on caring for them, and the main takeaway is this: they're tough, but the caudex rots easily if you overwater or the drainage is poor.

The guide stresses watering according to each species' cycle. During active growth, let the top 3 or 4 centimeters of the substrate dry out; while dormant, water minimally or not at all if the caudex stays firm. A simple trick it suggests is to push a wooden stick about 3 centimeters into the soil to check moisture before watering.

For the substrate, it recommends a very airy mix, with one part organic material and one part mineral (river sand, perlite or pumice), and wide, shallow pots with good drainage holes. The caudex can sit partly above the soil; what you shouldn't do is bury it too deep or cut it.

Species mentioned include Adenium obesum, Pachypodium lamerei, Dioscorea elephantipes, Stephania erecta and Fockea edulis. For Adenium, it suggests pinching the tips if you want branching, and for Dioscorea it notes that its cycle can be reversed depending on the climate, so watering should follow when it sprouts or loses its leaves.

The guide also warns about common pests (mealybugs, spider mites and snails) and about protecting the plants from frost. Personally, I think it's a good starting point for anyone beginning with caudiciforms, although the watering frequencies are only indicative and should be adapted to your climate.

Source: JardineriaOn