Q.My Desert Willow looks terrible and the leaves are just tiny clusters at the ends of branches. What’s going on?
It’s about 10 years old and has been beautiful every year until this spring.
I live in southern Arizona.
We did have the coldest winter in the 12 years I’ve been here with over a month of consecutive nights below freezing. It did warm in the day time to almost normal temps. — 40-60 degrees.
I have babied this tree since I brought it home as a “branch” from a nursery. The fact that it grew at all was amazing.
This is very depressing. What can I do?

Certified GKH Gardening Expert
It may be an insect or mite pest, possibly thrips. It's really hard to see details from the photos, but I think I see leaf stippling/spotting, and then the stunted growth is characteristic of some thrips infestations. I think it will take a keen experienced eye on site with a hand lens to look for tiny black enlongated insects. Nutrient deficiency is another possibility, but I lean toward the pest problem as best guess.
I suggest that you contact your local U of A extension office and see if they will send out a home horticulture advisor, or give you a location to take a sample of the foliage. It should be a free service. The alternative is to hire a consulting arborist, plant health care specialist or a certified arborist from a tree service that provides tree and landscape pest control.