
Conventional wisdom says that you need a clay pot to grow cactus. As we know, conventional wisdom is often wrong as it is in this case. This clay pot was previously home to this Birds Nest Sansevieria. Regular readers of this blog know for sure that I would not grow any plant in a drain hole pot. No Martha devote here. I am, however, a big fan of recycled pop/soda bottle planters.

The cactus (is it an Echinocactus?) is living in the clay pot but it's growing in a recycled pop/soda bottle sub-irrigated planter (SIP, aka "self-watering). I can hear the chorus from the peanut gallery saying, "You can't do that”. They continue by saying that self watering pots are only for moisture loving plants like Peace Lilies (Spathiphyllum). Not true.
This cactus has been growing in a pop bottle SIP since September 2007. Using the weight method of watering (using a scale) it has been amazing to observe how little water it uses. Think biofeedback. Use a scale and your plants can communicate with you.
There is no way that you can feed water to a plant like this using the top watering drench and drain method. Using capillary action, the plant receives water with science lab accuracy tuned to its precise needs related to its environment.
I wonder how many cacti and succulents are killed each year by drain hole watering malpractice. A more significant question is how many plants of all types are killed each year by this seemingly intuitive but malpractice.