1. How to take care of the Apple cactus?
Keep this cactus on the drier ide of watering and give it an extremely well-draining potting media. This plant loves to stay humid during its growing months of spring and summer, so keep the roots moderately dry and keep it out of AC drafts. Give it a spot with at least 3-4 hours of sun or extremely bright indirect light through the day.
2. Why is my Cereus repandus going black?
Blackening of any succulent is a sign of rot due to overwatering. Touch and feel the blackening area, if its soft and mushy to touch, take stem cutting from the top healthy portion and try propagating the plant in a fresh potting mix.
3. How often should I water my cactus?
Watering your cactus depends entirely on how much light it is getting. Overwatering is the biggest killer of these plants. Water only when the soil is completely dry, this plant loves to stay on the drier side. Do a finger dip test for dryness and if completely dry wait for a day or two more before watering.