How to revive Teddy Bear Magnolias with poor foliage, black/grey edged leaves?

[NavK]

  

What is wrong with my Magnolias ? The raised bed, where they sit, get plenty of water, so can't be drought.

[JacobZ]

Hi @NavK,

Thank you for your question and welcome to the Bunnings Workshop community, it is fantastic to have you with us.

My suggestion is that this is happening due to either root rot or nutrient deficiency.

I'd suggest checking the base of the plant, pulling back the mulch to reveal the soil beneath, and checking whether the soil is sodden or not. If it is sodden, and you haven't had any rain recently, it is likely that the soil is not draining adequately. Magnolias do not like having wet feet, so if the soil is sitting wet for too long, there will be issues.

This can be addressed by carefully breaking up the soil around the base of the tree, ensuring you don't damage the roots, and adding organic matter such as Richgro 25L All Purpose Mushroom Compost to the base of the tree. This will promote microbial growth and earthworms, which will help to break up the soil allowing it to drain more freely.

The next potential issue is nutrient deficiency. This can be helped by applying a general fertiliser such as Seasol to the base of the plant ensuring you follow the manufacturer's instructions for mixing.

You might like to check out Growing, Pruning & Caring for Magnolias for some additional guidance.

Also, allow me to tag @Noelle, our resident horticultural expert to see if they have any advice.

Let me know if you have any further questions.

Jacob

[Noelle]

Hi there @NavK 

The symptoms showing on your magnolia leaves are almost certainly due to "wet feet".  Pull the mulch back from around the trunks to allow the soil to breathe and check how wet the soil is.  Sitting along the base of a retaining wall it is possible there is significant moisture draining into your bed from the higher level behind the fence. You may need to run a drain at the base of that wall to carry excess moisture away.