How to treat Teddy bear magnolia leaves yellowing?

[sj20]

Hi, I’ve had my teddy bear magnolia planted for about 6 weeks now and the leaves have brown spots and are yellowing.

I water once a week and get sun all day until mid afternoon which is then dappled shade/sun. 
Any advice greatly appreciated please.

 

  

[EricL]

Hello @sj20 

Welcome to the Bunnings Workshop community. It's sensational to have you join us, and thanks for sharing your question about your Teddy Bear Magnolia.

It looks like your Teddy Bear Magnolia is experiencing some transplant stress, which is quite common within the first couple of months after planting. The yellowing leaves with brown spots, especially on older, lower foliage, suggest a combination of natural leaf drop, watering inconsistency, and possibly a mild fungal issue—nothing too alarming at this stage, but worth monitoring closely.

Your watering schedule of once a week can be fine once the plant is well established, but during the initial establishment phase (the first 2–3 months), young magnolias often need more regular watering. This is especially important with full sun exposure, as your tree receives strong light for most of the day before getting dappled shade in the afternoon. I’d recommend watering deeply twice a week for now, especially if the weather’s warm, and making sure the water is penetrating deep into the root zone rather than just wetting the surface. A moisture meter, available at Bunnings, can help you check how well the water is reaching the roots.

The brown spots on the yellowing leaves may be a minor fungal issue, which can occur when the foliage remains damp, or the plant is under stress. If you want to be proactive, you could apply Yates Liquid Copper Fungicide, which is gentle and safe for ornamental trees. However, if the new growth at the top looks healthy and glossy—which it appears to in your photo—there’s a good chance the tree is simply adjusting and will bounce back with consistent care.

Adding a layer of mulch (like pine bark or sugarcane mulch) around the base of the plant, keeping it a few centimetres away from the trunk, can help retain soil moisture and regulate root temperature. Also, avoid fertilising right away unless you’re using a mild seaweed tonic like Seasol, as heavy feeding too soon can stress a young tree further.

If you continue to see rapid yellowing or if the new growth becomes affected, we might need to reassess soil drainage or consider a root issue, but for now, your magnolia looks like it's on a fairly typical settling-in path. Let me know if you’ve added any soil improvers or if you’ve mulched already—that can help tailor the next steps more accurately.

Please remember to wear personal protection such as gloves, goggles and a mask when spraying your plants.

If you need further assistance, please let us know.

Eric

[sj20]

Thanks for your reply Eric and your wonderful advice. I did add some Osmocote compost to the Osmocote garden soil when planting, followed by garden basics mulch. 
The first few weeks I watered a few times a week but thought I was overwatering so pulled back to once a week. I will give it a spray with the copper fungicide and see how I go. 
Thanks again. 

[MitchellMc]

Hi @sj20,

Check the soil every few days, and if it has dried out, water the plant. Whilst still settling in, you'd likely need to water at least twice a week. If the soil is still wet when checked, don't water.

Also, do you have those pebbles up against the base of the tree? If so, I'd drag them back a bit as they'd likely be quite hot on the root area.

Mitchell

[sj20]

Hi Mitchell,

Thank you! No, the pebbles are about 20cm away from the trunk. 

[EricL]

Hi @sj20 

That is good to hear that the pebbles are away from the trunk of the tree. Just keep observing the health of your tree. With any luck, the steps you've taken will help it on the road to recovery.

If you need further assistance, please let us know.

Eric