Root Rot

Overwatering

To address root rot in pincushion cactus, first, cease watering immediately and allow the soil to dry out completely. If the plant is severely affected, unpot it and remove any mushy, black roots with a sterile knife, leaving only healthy tissue. Treat the remaining healthy roots with a fungicide recommended for cacti. Repot the plant in fresh, well-draining cactus mix and ensure the pot has adequate drainage holes. Resume watering sparingly, only when the top inch of soil feels dry.

Root Rot

Overwatering

To address root rot in pincushion cactus, first, allow the soil to dry out completely before watering again. If the plant is severely affected, remove it from its pot, trim away any black, mushy roots, and repot in fresh, well-draining cactus mix. Ensure the pot has adequate drainage holes. In the future, water only when the top inch of soil feels dry to the touch, and reduce watering frequency during the cooler, dormant months.

Mealybug Infestation

Mealybugs are small, white, soft-bodied insects that feed on the sap of the pincushion cactus, often hiding in crevices or under soil debris.

To combat mealybugs, first isolate the affected plant to prevent spread. Use a cotton swab dipped in alcohol to dab directly onto the pests, effectively killing them without harming the plant. For larger infestations, applying a neem oil solution or insecticidal soap can be effective. Ensure to treat the plant and surrounding area thoroughly, as mealybugs can hide in the smallest of spaces. Regular monitoring and repeat treatments may be necessary to completely eradicate the pests.

Fungal Rot

Fungal infections often occur due to poor air circulation or overly humid conditions, rather than direct watering issues. These conditions allow fungi to thrive and infect the cactus, leading to rot.

To address fungal rot, it's crucial to first remove any affected parts of the cactus with a sterile knife to prevent the spread of the infection. Ensure the plant is in a well-ventilated area with low humidity. If necessary, apply a fungicide specifically designed for cacti following the manufacturer's instructions. Improving air circulation can be as simple as relocating the plant or using a small fan in the area.