The Lithops watering calendar: a season-by-season guide

Almost every Lithops failure traces back to watering at the wrong time of year, not to watering too much or too little in absolute terms. A correctly watered Lithops drinks deeply during two short windows and goes essentially dry during two long rest periods. The total volume of water per year is modest. What matters is when that water arrives.

This guide is calibrated to plants grown in the northern hemisphere. Reverse the months for the southern hemisphere. Adjust slightly for local climate — a plant in cool maritime England will need less than a plant in dry continental Arizona, and the windows shift a few weeks either way.

From roughly January through April, mature Lithops in cultivation enter the molt. The new leaf pair is forming inside the old, drawing exclusively on stored water and nutrients. Adding water during this window is the single most damaging mistake in Lithops culture.

The visible signal is the cleft beginning to widen and the outer leaves softening. Once you see that, the plant is committed to the molt. Withhold all water until the old leaves are completely papery and the new pair is fully expanded — typically six to ten weeks. The plant will shrivel visibly during this period. That is the correct outcome.

When the old leaves are dry husks and the new pair is firm and full-sized — usually April or May in the northern hemisphere — give the first deep watering of the year. Soak the substrate thoroughly, let excess drain, and then wait at least two weeks before considering another.

This first watering is the most psychologically tempting to repeat. Don't. The plant has spent months drawing on internal reserves; flooding it now invites root failure. One deep watering followed by a long pause is the goal.

Through May and June, plants are in active growth. Water deeply when the plant has visibly firmed up from the previous watering and the substrate is bone dry — typically every two to three weeks, depending on heat, light, pot size, and substrate. A small pot in a hot, bright window may need water every ten days; a large pot in mild conditions may go a month.

Always water in the morning, never in the evening. Cool, damp substrate overnight is the most efficient way to lose a Lithops to root rot. The plant should be dry within 48 hours of watering.

From late June or July through August, Lithops enter their summer dormancy. In habitat this is the hottest, driest part of the year, and the plants shut down to wait it out. Watering during dormancy when temperatures exceed 30 °C is high-risk: warm wet substrate is a perfect environment for root rot.

The plant may wrinkle slightly. Leave it. The body has enough reserves to coast through six to eight weeks of dryness without distress. Keep it bright (some shade against direct midday sun in extreme heat) and dry.

September into October is the second growth window and the time most Lithops flower. Resume watering at the same cautious pace — deep soak when the plant has firmed up and the substrate is dry, then wait. Flowering plants benefit from one or two slightly more frequent waterings during bloom, but never to the point that substrate stays moist between cycles.

Flowering signals the plant is approaching the end of its growth year. After the flower fades, taper watering quickly.

From November through January, Lithops should be kept essentially dry. In a cool, bright location, mature plants tolerate zero water for the entire winter. In warmer indoor conditions, a single very light watering in mid-winter can prevent the plant from depleting too far before the molt begins, but err on the side of less rather than more.

This is the period before molting begins. Any water left in the substrate as the plant transitions into the molt window will cause exactly the problems described in the molting cycle guide — stuck splits, stacked leaves, rotted clefts.

Jan–Apr: no water (molt). Late Apr/May: first cautious watering. May–Jun: deep watering every 2–3 weeks. Jul–Aug: no water (summer dormancy). Sep–Oct: deep watering every 2–3 weeks; flowering. Nov–Dec: dry rest, optional single light water mid-winter. Always water mornings, never if the plant is showing any sign of beginning the molt.