Platyceria watered too abundantly, they get sick easily. Wet, a cold substrate favors the spread of Rhizoctonia fungi, which infest the rhizomes and the epiphyseal part of the leaves, causing them to blacken. Fighting the disease is difficult. First of all, watering should be limited, then spray the plants with Previcur N (0,15%) the Fongarid M (0,1%).
Scatters are often found on platycerias. You can get rid of them, putting fertilizer sticks with insecticide in the ground (Orthene), e.g.. "Zielony Dom" company.
Millipedes and wireworms can nest in the ground and wooden containers, biting holes in rhizomes and leaves. These pests should be caught in traps - hollow pieces of potatoes or fruit.