How to treat Magnolia sweet carolina losing its brown underside leaves?

D98

Hi there community, 

I planted these magnolia sweet Carolina’s about three months ago. there is 12 over all but 9 of these have started loosing there deep brown under leaf colour can someone help me in the right direction to fix this? 
I’ve also noticed that some of the stems, limbs have gotten a dark tinge to them aswell. Could this be fungal? 
I’ve also noticed these little scale things on some of the leaves I removed them but I’m  hoping there’s a way to stop them from coming back. 
We live in Perth and have had a pretty wet winter could this have something to do with it? 

I’ve also added a photo of what they looked like when we first got them.  

any help or product recommendations is much appreciated. 

thank you 😀

MitchellMc

Welcome to the Bunnings Workshop community @D98. It's sensational to have you join us, and many thanks for your question about Magnolia Care.

It looks like you’ve already picked up on what’s happening. Those little “scale things” are likely scale insects, and they can cause some discolouration and stress to the plant. I’d suggest giving your Magnolias a periodic spray with a horticultural pest oil. This will coat the scale and stop them from returning, and it’s safe to use regularly as a preventative.

As for the leaves losing their deep brown underside, that colour tends to be most vivid on young, fresh growth. Over time the older leaves will often fade, which is perfectly normal. From the photos, the plants themselves actually look quite healthy overall, so I wouldn’t be too worried. Keep an eye on new growth, and as long as that’s coming through clean and strong, your Magnolias are doing well.

The wet Perth winter could also have contributed to some of the darker tinges you’re seeing on stems and leaves, but unless you notice active dieback or spreading damage, it’s unlikely to be a serious fungal problem. Regular monitoring and the pest oil treatment should keep them on track.

You should find this guide useful: Growing, pruning and caring for magnolia trees.

Please let me know if you have any questions.

Mitchell