Trouble with Magnolia Tree Leaves

We had a customer asking about their magnolia tree, what to do about the leaves turning kind of funky looking.

Sometimes we’ll see this, pretty common on magnolias in a wet summer or wet spring, they can get a little gray powder on them and that’s a fungus called powdery mildew.

It generally does not kill the tree, it only disfigures the foliage. But if we continue to have this environment that allows it to grow, it’s not a bad idea to spray a fungicide on it. 

Again if anybody’s reading, if you’re gonna spray a fungicide, never, never, never, spray at midday. It’s just too hot this time of year. Late evening is a great time to spray, that’s the longest time period before we get hot again the next day.

Try not to spray when we’re above 85-86 degrees. Once we go above that threshold, we just don’t want to spray.

I had somebody in the store a few weeks ago with a maple tree and the leaves had gotten bigger than my hand. We have a long wet cool spring, I mean I was wearing a Carhartt the first week of June. It was a really cool spring, those leaves grew to that environment, now that environment has drastically changed and it can’t support the entire leaf.

So what the plant does is it’ll burn the margins around the edge of the leaf, and it’s basically burning from the tip back. Now you want to make sure it’s got enough water. Older trees that are established should have no problem with this, but a newly planted tree would be something I would check. Make sure there’s good moisture in the ground and present so that the plant can bring up moisture. Sometimes it can’t bring it up fast enough, and that’s why you’ll get that brown margin around the edge of the leaves.

That’s not uncommon, it’s just a very drastic environmental change. Usually in May we have some high 80s and 90s, and we just didn’t have that this year, and that slows the plant down so it doesn’t overgrow its leaves. This year we stayed really cool, and those plants did overgrow their leaves. 

I noticed that with some Serviceberry and stuff, of almost a first flush of leaves, and then shedding a little bit. Birches are shedding, Serviceberries are shedding, and it’s because the inner leaves don’t make as much food as the outer leaves. So when the tree gets stressed, it’s going to drop some of that inner foliage. It grew too many leaves, basically.

 It grew enough leaves for the environment that it was originally in, but now that environment is drastically changed, so it is shedding. 

Don’t trim this time of year. Light pruning for shaping, a snip here, a snip there, not a big deal. Crossing branches, that’s probably not a huge deal. But you do not want to do hard pruning in the summer months. It’d be like going out there and pruning in negative 20 in the winter time. When the environment is extreme one way or the other, hot or cold, you really want to just leave the plant be in that time frame. Then early spring late fall, those are better times to prune.

Questions? Email us at [email protected] or call one of our two locations: Portage (330-499-0101) or Everhard (330-492-1243).