I planted this 30 gallon plant maybe 4 months ago.

It's in full DFW sun all day (from 8AM to 5PM). Is it fried or diseased?

I noticed it got a little brown after a squirrel dug a deep hole into the roots (like a 5 inch deep hole) and I discovered some of the roots dried out so I filled in the soil and watered deeply. Been watering avery 5 days (deep/slow watering for maybe 20 minutes so it saturates the roots).

Thus it's either it was damaged by the squirrel or it's getting too much sun.

My guess is sunburn.

Full sun in DFW is intense enough to scorch young transplanted trachys pretty easily I would guess

It’s still establishing and the squirrel wasn’t helping. Give it time get more roots established so that it can move as much water as it needs to handle full DFW sun and still look good. Nursery leaves never stay pristine for long . The new leaves it grows in the ground will be tougher.

That is sunburn and the leaves are semi closed/pleated indicating lack of moisture.

20 minutes every 5 days is most likely not enough for an "established" trachy in your area. As others suggest, the new leaves will be more resistant to sunburn, if properly watered.

Also your trachy probably will not grow much until the weather cools a bit.

Shade cloth would probably help slow further damage.

2-3 years for your palm to establish.

Edited 7 hours ago7 hr by jwitt
Established

These aren't suited to full sun in Texas. Definitely sunburn. They need shade, part shade or part sun with afternoon shade. It may never fully acclimate to full sun. You will see it will put on nice green leaves in fall, winter and spring and they will look good, but once we get around June they'll start to burn. I've seen this over and over with with my Trachys. I've tried to acclimate them but they can't handle it and I've tried multiple species, so they are under 40% shade cloth until I get some shady spots to put them in. I have one larger one that gets a lot of sun and so far its not burning but its very yellow compared to the rest even with fertilization. If you want a full sun palm for your area I would try Sabal palmetto or Sabal mexicana,

Do you have some kind of rock in the soil mix? Pea gravel or sand? It needs more clay/loam type soil to retain moisture and stay moist in your climate. See how it does after fall and next spring but as others have mentioned in your climate it may be best in more shade. If you amended the soil around it with sand or rock you will probably need to dig up and move with better soil that will retain moisture and the afternoon shade is a good idea there. You have had temps over 100 there lately and the palm will do better in Sept-Dec as these palms prefer temps 65-85F to grow best. There are several people growing Windmill palms successfully in the DFW region

One of My vids on picking the right palm for your climate

https://www.youtube.com/watch?v=Mpj1D7oU_P4