Tree Care Advice needed on Eucalyptus and Cottpnwoods

We live in Arizona ... on our property we just bought are several old growth Eucalyptus and Cottonwoods ... which species of each .. we don't know.

Our Questions is .. on the watering and the fertilizing of both kinds of trees.

Do the Eucalyptus need as much water, as the Cottonwoods do? And if so.. Year round?

Also, will Ironite help both trees to flurish?

Some of the Eucalyptus seem to be yellowing and one looks almost dead.

We just became aware of some infestation hitting Eucalypus trees in other states and will give ours a very good look tomorrow.

Does anyone in Arizona, or other areas have any advice.

Thanks Autumn16 ... Sally

I feel bad this thread has been sitting out here for so long. I can't answer any of your questions about Eucalyptus because I don't grow any of them but I'll take a stab at the Cottonwood even though you are zone 9 and I'm 5. You could not provide the binomial to the Cottonwood you have which would have been a big help because I don't know which one you have. You might have a Cottonwood out of its range. Anyway, in my neck of the woods, a winter drought can be far worse than a summer drought. Winter droughts take a tremendous toll on plants so we always hope we get enough snow. In years that this does not happen, we try to take what snow we get from the driveway and sidewalks and transfer it to where trees are growing. I would think that you would need to water your Cottonwood throughout the winter months. That tree won't need nearly the amount of water it requires during other times of the year but I still think it is going to need to stay hydrated. That is a deciduous tree though and it is going to need some rest time so don't get overzealous in the watering department, probably just enough to keep the area around the root ball slightly damp. Fertilizing beyond August might not be a good idea. Best to stop fertilizing now and begin fertilizing again when the tree is in active growth sometime next spring.

I can't answer your questions about the use of Ironite either because I know nothing about your soil composition. You might want to take a sample of your soil to a service and find out. That's what I do here. The charge is nominal and I have found wild fluctuations on my property here. Most people don't have these wildly different readings but I've got wetlands, lowland woodlands, upland woodlands, lawn areas and well you get the idea.

Best wishes to you and here's hoping some arborists out there spot this question and respond to you.

Thank You for your response. Appreciate it.

We have decided to call a Tree Doctor in. Also we are going to get in touch wiht our Local Cooperative Extension.

Ours are still putting out sapplings, but they also are starting into their winter, drop their leaves mode .. so we need to get someone out.

Thanks again.

Autumn16 ... Sally