How to revive sick mop top trees?

[YollyF]

 my mop top trees are coming back after a good prune over winter which I do every season.  I don’t remember any of the new growth looking so curly like

in the pictures below? I have approx 6 trees across the front of our house, some were planted years ago before we purchased the house, others are about 6 years old. I’ve had a look inside the canopy and cannot find anything obvious and the other growth seems super healthy. 
we have had a particularly dry winter here, however I’ve never watered the oldest trees only the newer ones we have planted. 
Any ideas? 

[MitchellMc]

Welcome to the Bunnings Workshop community @YollyF. It's wonderful to have you join us, and many thanks for your question about mop top care.

The curling of your mop top tree leaves, especially at the tips, could be due to a few factors. Dry conditions or irregular watering can cause leaves to curl as the tree tries to conserve moisture. Even though you haven’t watered the older trees, mild dehydration could still affect them. Insects like aphids, spider mites, or leaf miners might also cause curling, though they can be hard to spot. Nutrient deficiencies, particularly in potassium or magnesium, can also lead to curled leaves. Another possibility is a fungal or viral infection, though this typically comes with other symptoms like yellowing.

Start by checking the soil moisture and ensuring the trees are getting enough water. Inspect the leaves for pests, and consider applying a balanced fertiliser to address any nutrient gaps. If the issue persists or worsens, consulting an arborist might be necessary to rule out infections or other underlying causes.

As this is a bit of a peculiar one, let me tag our resident gardening experts @Noelle and @mich1972 to see if they have any thoughts.

Please let me know if you have any questions.

Mitchell
 

[mich1972]

@MitchellMc That a bit of an odd one. As you Suggested it could be a few things. I wondered Thrips possibly or has the root system hit something that could be causing the new growth to curl. I’ll wait until @Noelle has a look at it 

[YollyF]

Thanks. I went and visited my 2 local nurseries to see if they had any ideas. One thought aphids and gave me an insecticide to spray and suggested cutting back some growth before treatment. I cannot find any aphids. 
the other suggested white oil and give them a good water but make sure they are not too wet. 
I have 6 mop tops across the front and 4 out the back and all are showing signs. 
the only other problem I could think of is that when I pruned in winter all trees had scale, so I treated that after pruning, would that have some affect on them now? 
have inserted some more images 

 

  

[MitchellMc]

Hopefully, @Noelle will be able to join the discussion soon @YollyF. I cannot locate any information on this specific issue, so we really need her expertise as a horticulturalist.

Mitchell