Jane Magnolia Leaf Disease

I planted a Jane Magnolia this past spring (2021) in growing zone 7a. The site is southwest facing with full sun. The shrub had full flower pods, some of which bloomed, others seemed to "rot" away and never open. Big, green leaves opened shortly thereafter, but later in spring and then into summer, the leaves began to get white spots all over them, and some began to yellow and drop off. Late summer, a new flush of growth started at the base of the plant with new leaves growing "inside" the older branches (looks like a shrub within a shrub). Meanwhile the older branches have small flower pods started for next spring presumably. So, the question is, is my magnolia okay? What is the going on with the spotty leaves? I've included a picture of what it looked like a week ago. Since then, more leaves have yellowed and dropped. Should I be doing anything to help?

Has it been a wet year in MD?

Those leaves look like they could be afflicted with powdery mildew, which is annoying and ugly but not fatal.

'Jane' is one of the Little Girl series of magnolias, and they want to be a multi-stemmed large rounded shrub or small tree. Extra stems is its game, and this is stimulated in your case because the mildewy leaves are not photosynthesizing efficiently - so the plant produced new growth with fresh uninfected leaves to pick up the slack.

I would try to rake up and dispose of as many/all of those old leaves as you can, to reduce disease pressure next year. 'Jane' is pretty tough; I suspect you will have a good bloom display come spring.

After bloom time finishes next year, prune out any weaker or under-performing stems so that air circulation through the plant is improved and unimpeded. That should also help to reduce foliar problems. A balanced granular fertilizer (10-10-10) and supplemental watering during droughty periods is probably all 'Jane' will ever need.

Thanks for the advice! It wasn't particularly wet in MD this year and I studiously avoided watering the leaves instead of the base of the plant. I thought about powdery mildew as a culprit, so I will work harder next year to see if I can preempt any mildew from taking hold. The extra growth makes sense to compensate for the mildewed leaves. I plan to prune this into a tree form, so I will probably pinch off any additional growth lower on the plant to stimulate vertical growth. Thanks again!

You are quite welcome. Good luck with your plant.

Wonder where this tree is planted in proximity to house, walls and other structures that might impede circulation. Magnolias here seem predisposed to mildew when you see them crammed against a house foundation or attempts to grow them as an evergreen screening wall.