If My Barrel Cactus Turns White, Will it Recover?

Barrel cacti have accordion-pleated stems bearing fierce spines.

Barrel cacti have accordion-pleated stems bearing fierce spines.

Succulent plants that reflect their native, harsh environment, barrel cacti (Ferocactus spp. and Echinocactus spp.) consist of a stout cylindrical stem covered with clusters of formidable spines held on ridged portions of the stem. Normally, a barrel cactus has a green stem, but various factors can cause a white to yellowish discoloration. Recovery depends on the severity of the problem and the baseline health of the affected plant, with a well-grown, healthy barrel cactus having a good chance of surviving diseases and environmental stresses.


A barrel cactus grown outdoors develops a tolerance to sunlight on its south side. If the cactus is transplanted without maintaining its original direction orientation, then its skin can sunburn. Symptoms begin with the skin bleaching to light green and then white to yellow. In severe cases, the tissue dies, forming hardened yellow to brown areas. Prevent sunburn by marking the south side of a barrel cactus with a spot of paint before moving the plant, and place the painted area to the south in the plant's new location. Sunburn also occurs on indoor plants that are moved abruptly to locations with bright sunlight from locations with less sunlight. When a barrel cactus is not used to strong sunlight and you want to move it to site with strong sunlight, then gradually accustom it to increasing levels of sunlight over a period of several weeks to prevent damage. Usually, a sunburned barrel cactus recovers but can be permanently disfigured.

Insect Damage

In warm-winter areas of the U.S. South and Southwest, a kind of leaf-footed plant bug (Narnia femorata) that feeds on cacti can cause whitish splotches on barrel cacti. The bug inserts its piercing, sucking mouth parts and sucks out plant juices. Feeding removes the chlorophyll and creates white circular areas. Remove the insect as soon as you notice it in order to prevent damage that will weaken your barrel cactus. Generally, a barrel cactus affected by the bug doesn't die, but it becomes weakened and doesn't grow as well because it doesn't have as much chlorophyll for photosynthesis as it had previously.

Freeze Damage

Barrel cacti are generally hardy in U.S. Department of Agriculture plant hardiness zones 9 through 10 or 11, depending on the species, with the Chihuahuan Desert species Ferocactus hamatacanthus hardy in zones 6b through 10. When exposed to temperatures below freezing, most varieties experience damage, beginning in their thinnest areas, such as the ridges, or tender new growth. The amount of damage depends on the duration and severity of the cold and can result in death. Often freeze damage exhibits at first on a cactus' exterior as pale to yellow, turning black, tan or brown, depending on the species and the extent of damage. Protect your barrel cactus from cold weather by taking it indoors if it is in a pot or by covering it with frost blankets or burlap before freezes occur if it is an outdoor landscaping plant.

Other Damage

Hailstorms cause white areas that look like polka dots where the impact of the frozen hailstones struck the skin of a barrel cactus with enough force to kill the tissue. Often damage is just on one side of the cactus, where the wind drove the hailstones. The barrel cactus recovers and produces unblemished new growth, but the physical damage remains on the plant.

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