Button plants (Conophytum spp.), one genus of many called living stones, are not the easiest plants to grow. True enough, they’re actually fairly simple to start from seed and to grow on to their full size: just treat them like any other seed-grown plant. It’s keeping them going from then on that’s complicated.
You’ll note that the information given here concerns only conophytums. Most other living stones (Fenestraria, Frithia, Lithops, Pleiospilos, etc.) need similar care, but they tend to go dormant later in summer rather than in spring. So, you really to need to treat conophytums separately.
Outdoors, conos (as collectors call them) rarely survive outside of their native habitat. Even in a dry Mediterranean climate in zone 9, as in southern Europe and California, which theoretically replicates their original conditions, they tend to peter out quite quickly.
Conophytums show up occasionally in garden centers among the other living stones, but again, rarely live long in the average home. Still, a rapid description of their needs—full sun and very careful watering—scarcely seems impossible to meet. Even so, they tend to die off rapidly.
The secret to success with conophytums is to understand that they are spring-summer dormant and only put on real growth in the fall and to water accordingly.
Spring Dormant, Fall Growing
What complicates things for home gardeners is that conophytums go fully dormant in the spring just when their other houseplants are springing into new growth. Worse, their leaves start to shrivel up, leading us to assume they need water … and that’s a fatal error.
Don’t water conophytums at that season! They’re dormant! Instead, start to water in late summer, when temperatures begin to cool and the old, dried leaf (actually two conjoined leaves) looks fully dead. You may not have watered for months, but the old leaves will start to pull back to reveal a new leaf inside. That’s the time to water. A fresh leaf will soon emerge from the shell of the old one.
Keep watering quite abundantly for about two months, from late August into October, much as you would any succulent. This is also when they bloom, with startlingly pretty flowers arising from an often almost imperceptible slit in the leaf. Then water only as needed through fall and winter, that is, when the soil is just about—but not quite—bone dry. Also, give them the strongest sun you can at that season.
Stop watering again in spring, about early April, when the leaf starts to appear wrinkled, then let them dry out completely. From there, just repeat the cycle.
Growing conophytums seems simple enough, but I warn you: it’s easier to write about them to actually grow them!