Hi, This is a Magnolia alba grafted plant growing in a large clay pot in my courtyard. It gets morning sun only that too under green net because my summers are too hot more than 100F consistent. Rest of the day it gets bright shade. I kept it in same pot after buying from nursery. The soil appears to be a mix of loamy soil, leaf compost, coco peat. It drains well. I have watered it well and never allow it to wilt. What do these black spots and burned edges indicate? I also notice some white spots on the leaves. These problems are only with the top level leaves, rest of the 25 + leaves are fine. Is this some pest, disease or some environmental issue? Please help as i do not want to lose this plant. I am growing gardenias happily and believe these should grow well too. PS: A M.Champaca bought from same buyer at same time in same pot size and same soil mix is growing happily with buds in it, just next to this one. Khabbab Lahore, Pakistan
Thank you. How can i rectify it? I know my tap water is alkaline so i have already amended top soil with bit of ferrous sulfate and sulfur. What can i do to prevent further salt damage?