AusBonsai

I have an old Callistemon which is looking very sad. Leaves have yellowed and gone spotty. Can anyone please help identify cause and tell me how to treat it?

Thanks

I can't make out much detail from those photos so only guessing here.

Do some of the spots rub off? Callistemon sometimes get a scale insect on them. Try a horticultural oil (Eco oil, etc) to kill them.

Callistemon are also Myrtacea family so are susceptible to Myrtle rust. Hope that's not this case but you can check on what to look for to ID for it and see if the symptoms match.

Thanks shibui. No it doesn't rub off. I will look into myrtle rust

Hopefully it's not myrtle rust here in Adelaide - I could be wrong but I don't think we officially have it here (yet). It might be worth moving this plant away from any others, to an area sheltered from the wind if possible, just in case.

I also hope it is not Myrtle rust. From the little I can see in the pics the marks do look different and I think there are other rusts that may also affect callistemon.
I had one that looked a little similar for a few years. Pretty sure it was some sort of insect, possibly scale. I could not see the bugs but they left dead patches where they fed on the leaves. Eventually I used insecticide and the plant cleared up and grew well.

From what I can see online the photos of myrtle rust don't match what I am experiencing. My tree has dark spots all over both sides of leaves that won't scrape off. its as if it is in the leaves itself that the discolouring has taken place.