How to treat brown spot on my magnolias?

[hibbend]

 

 

Hi I have for Magnolias they are approx 2 years old, they are in pots around of pool

they have a brown spot on the leaves and also appear to have a bug eating the leaves. Not sure what I should do is liquid copper the correct thing to use thanks

Deb

[MitchellMc]

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

You might like to check out this helpful guide: How to diagnose a sick plant. My first thought is if these plants receive full sun, then the leaves are being scorched. Magnolias enjoy a few hours of sun per day, but if they are exposed to full mid-day or afternoon sun, that might be a bit too much for them. Also, being so close to that dark-painted fence wouldn't be helping as it would be absorbing heat during the day and radiating it onto the plants. Could you move the plants to a more sheltered spot?

That leaf looks like it might have had a caterpillar chewing on it. If it's only one leaf, then it's no cause for concern.

Let me mention a couple of our gardening enthusiasts, @mich1972 and @Noelle, to get their thoughts.

Please let me know if you have any questions.

Mitchell
 

[Noelle]

Definitely looks like sun scorch. The leaves also look a little dry which would make them more susceptible to burning.

If you can, move the pot so that it gets shade for most of the day (the pot, that is) because being in full sun not only dries the potting mix out quite rapidly, it also causes it to get quite hot and that can in turn damage the roots. Magnolias like a cool root run. Mulching the surface of the pot with sugar cane or other organic mulch would assist but ideally if the pot can be in the shade during the hottest hours of the day, the plant will do better.

Water regularly to ensure the roots are kept moist but not wet and feed with a fertiliser suitable for acid-loving plants (azaleas, camellias, rhododendrons, etc). Since we think the condition is caused by where the plant is growing, there's no need to apply any sprays at this stage. Just keep an eye out for pests and blast them off with the hose if you find any.

[mich1972]

Yes definitely looks like sunburn. Mitchell and Noelle have given great advice 😃