Lithops, often called “living stones,” are unique succulents known for mimicking pebbles and rocks. They typically grow compact and low to the ground. Etiolation is a common plant response to insufficient light, causing stretched, weak growth as the plant seeks a light source. This article explores what causes etiolation in Lithops and how to address it.
Identifying Etiolation in Lithops
A healthy Lithops maintains a compact, stone-like appearance, often sitting flush with the soil surface. It typically consists of two thick, fused leaves with a distinct fissure at the top. In contrast, an etiolated Lithops appears noticeably stretched and elongated, growing taller than its normal, squat form.
This stretching causes the plant to lose its characteristic “stone-like” shape, becoming more columnar. The leaves may also appear paler or less vibrant in color compared to a healthy, well-lit specimen. This lengthening indicates inadequate illumination.
Causes of Lithops Etiolation
The primary cause of etiolation in Lithops is insufficient light. These succulents originate from arid Southern African regions, naturally exposed to intense, direct sunlight for many hours daily. Their compact form adapts to these harsh, sunny conditions.
When Lithops lack necessary light intensity, growth hormones trigger elongation of the stem and leaves as they seek a brighter environment. Common indoor conditions, such as placement too far from a window, in a north-facing window, or in a constantly cloudy climate, often fail to provide the intense light Lithops require. While light deficiency is the main driver, excessive watering, overly rich soil, or too much fertilizer can also contribute to stretched growth by promoting unnatural vigor in low light.
Correcting Etiolated Lithops
Once a Lithops has stretched due to etiolation, the elongated growth cannot revert to its original compact form; the stretched tissue remains. However, it is possible to encourage healthy, compact new growth.
The immediate action involves moving the plant to a significantly brighter location. While old, stretched leaves will not change, new leaves emerging from the central fissure can grow compactly if proper light is consistently provided. This process requires patience, as Lithops typically produce new leaves only once a year, absorbing the old ones over time.
During this transition, carefully manage watering, especially when new leaves form and old ones are absorbed. Gradually acclimate the plant to stronger light to prevent sunburn on previously shaded tissue. Consistent, optimal light from this point forward will allow the plant to eventually replace its etiolated growth with healthy, compact foliage.
Preventing Lithops Etiolation
Preventing etiolation requires providing optimal light from the outset. Lithops need substantial direct sunlight, ideally at least 4 to 6 hours daily. A south-facing window is often best indoors in the Northern Hemisphere; an east or west-facing window can also work if southern exposure is unavailable.
For indoor cultivation, especially in less sunny climates or homes with limited natural light, supplemental grow lights are often necessary. Full-spectrum LED grow lights are effective. Position them at an appropriate distance to provide intense light without heat stress, typically 6-12 inches above the plants, for 10-14 hours per day.
When moving a Lithops from a lower light environment to a much brighter one, gradual acclimation is important to prevent sunburn. Slowly increase direct light exposure over several days or weeks. Also, ensure Lithops are not placed in shaded spots or areas where light is obstructed to maintain their compact growth habit.