This is why you want to avoid formal planting arrangements whenever these are not called for by formal architectural settings. If these were planted within the last few years, have not yet rooted out well look inside the original soil ball to make sure it is not dust or mud. Otherwise perhaps a heavy mite infestation of the foliage is possible, I do not know if podocarps are ever prone to these or not but the hot time of the year is when these are likely to become bothersome on outdoor plantings. Telltale signs of a heavy buildup are fine webbing encasing the shoots and a speckled appearance to the leaves. If you see either of these try looking at the leaves with a magnifier to see if mites are visible.

post a pic ... or 3 ...

i would never think water on 20 foot trees ...

water is a recent transplant issue ...

did you have a bad winter incident????

it is not uncommon for slight damage.. to not 'show' until the heat of summer.. finishes the damage ...

i have no clue about this specific plant.. nor your zone .. but pix would sure help ...

ken

Sorry, got side-tracked with holiday activities. Here are some pictures of the tree that has me concerned.

Another

Another

The last pic is of tree a few feet away, notice how much darker green it is.

Bump. Anybody?

Here is another pic, looking browner and more sparse by the day

The one in the last shot is dead. If this is not drought damage and you are in the US maybe your local USDA Cooperative Extension Service office can help you figure out what is going on.

It was nice while it lasted but def dead. We've had rains lately so hard to tell if soil was overly moist before. It has no tiny roots and what's there looks pretty dead. Have a new now waiting in the wings, but not knowing what went wrong makes it hard to avoid the problem next tume around, sigh...,

Rootball

Another

Sniff...I think this was a single trunk podo. Macrophyllus

Some plants just die.
Just like anything can happen to people.
A certain age point is not gauranteed.