Every year, we post photos from our years long experiment growing the African native lithops (living stones) in the garden. Our success underscore our contention that so much of the information you find on-line and in books, is simply incorrect. As we’ve discussed in the past, lithops are much more winter hardy than is generally accepted. Most authorities repeat the myth that living stones are not frost tolerant, but our plants have survived 11 degrees F in the ground, unfazed.
The other myth is that they don’t like water, and should kept dry. In our findings, this is the easiest way to kill lithops. Below is a cell pack, where we grew lithops from seed. It has been kept in an open greenhouse since mid-April, where it’s been irrigated twice daily, and subjected to 45″ of rain so far. As you can see, the lithops have been watered so much that most of the soil in the cell pack is gone, and liverwort (Marchantia) is growing on the remaining soil surface. In the greenhouse world, liverworts are the prime indicator that a plant has been kept much too wet. Not only are these lithops growing fine, but they’re also flowering. We will cover the greenhouses in mid-October, so the lithops will be kept drier during the winter.
I was talking with an open house visitor last week, listening to his story of killing containerized lithops with a few drops of water after running them very dry during the growing season. When they are kept dry, all of the lithops roots die, and while the plants may look alive on the surface, they can be killed at that point with a small amount of water. So, their death was not actually caused by watering, but by underwatering them in the months prior.
