We have a problem with one Magnolia grandiflora. It's a 28 year old tree and has been doing wonderfully well until last year . Then the new growth curled up and turned black along the leaf margins, eventully droping off. This was repeated this spring. There seemed to be no sign of insects or mould, so I had the plant and soil tested. No problems with nutrients. The other M. grandiflora, including 'Little Gem' are not effected. Searrching yoelded nothing. Most references say the plant has no problems. So, I can use some advice, hopefully from someone that has experienced the problem. Sorry, no pictures. I didn't know abouy this forum in the spring, and all the effected leaves are gone now.