Whengrowing a cactus indoors, be water-wise, sunlight-savvy, and discerning with drainage.
Identifying possible causes for the discoloration and making adjustments right away can sometimes be enough to stash your plant.
Learn more about why your cactus is turning yellow and strategies to salvage it.
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Improper Watering
Irrigation errors are the most common and often deadly reason for your cactus turning yellow.
Cacti are typically drought-tolerant, desert-dwelling species that like arid conditions.
Once root rot sets in, its difficult tosave an overwatered cactus.
While overwatering is a common killer, cacti can get dehydrated.
This can also cause them to turn yellow.
Once you start seeing wrinkling or thinning plant stems, this is usually a sign it needs a drink.
Severe dehydration can lead to root death, but it can take months for this to happen.
Thats why underwatering rather than overwatering cacti is a safer bet.
However, if all roots reach the stage of being brittle and black, your plant might not recover.
As this worsens, the yellow spots can turn brown and kill all or part of the plant.
This tends to be more of a problem outdoors.
Typically indoors, the challenge is providing enough light; sometimes, you might need to use indoorgrow lights.
Its also a good idea to gradually acclimate new cacti to their sunny spots.
Poor Drainage
Dont plant your cactus in a standard potting soil.
Use a ready-madecactus soilor mix up your own for better aeration.
Nutrient Deficiencies
Indoor potted plants can sometimes suffer from nutrient deficiencies that lead to your cactus turning yellow.
The fresh mix will also be higher in nutrients than the old blend.
Where possible, use a fertilizer specifically intended for cacti that contains more phosphorus than nitrogen.
Regularly inspect your plant for signs of pests.
If you spot them, dont delay in taking action.
A few insects are much easier to eliminate than a full-blown infestation.
Sometimes, its enough to wash away the insects with a blast of water.
Transplant Shock
Transplanting a cactusisnt too tricky.
These hardy plants are relatively forgiving.
Freeze Damage
If theres an unexpected cold snap, freeze damage can lead to your cactus turning yellow.
Less than a few hours of exposure usually only damages the outer layer of the plant.
Prolonged exposure to a hard freeze results in death.
Suggested Solutions
Overwintering your cactus indoors or in a greenhouse protects your plant from cold snaps.
If freezing temperatures are certain, its best to grow cacti indoors.
A yellowing stem is not the only sign you are overwatering your cactus.
The yellowing usually happens further up the stem, with the base of the plant turning brown.
Watering frequencies vary depending on the cactus species, home conditions, and the season.
Problems and Pests of Agave, Aloe, Cactus and Yucca.
The University of Arizona.
