Different palms need different amounts, and also it depends on how long they've been in the spot, and how long they stayed in a container before being put in the ground (for taproot palms). Palms like Queen Palms or Date Palms need the soil around them to be constantly moist (not soggy), and generally do better on a consistent water schedule (like from automatic watering). Palms like Cabbage Palm (palmetto) can go for long periods of time without water if they've been in the spot for a while.

If it's one of the palms that need moist soil, it also helps to water a wider area around the tree.

Thanks

Also...what type of palm do you have? I ask because there's some fusarium going around that kills some of the Palm types. If you're taking good care and they still look sad, call an arborist and see if there's an infection or something else is wrong.

We put the hose on ours (at a trickle) for several hours about twice a month--they seem to do just fine.

Fan palms need little to no water once they're established. I have a monster that's maybe 8 years old and about 20 feet tall or more that I last watered about 2 years ago when we went for about 3 months in the summer with no rain, and it started looking a little sad.

If you can identify the type(s) of palms you have and figure out their binomial (two-word) Latin name, you can research on line, and get a better feel for the conditions of their origin, and base your watering schedule on that information. for example, Queen palms (Syagrus romanzoffiana) are native to humid and frost-free parts of tropical and subtropical South America. They resent our low desert's dry air, and suffer a lot of damage in winter freezes. Grown in our desert environment, so dissimilar to the conditions of their origin, they look unhappy much of the year. Nothing quite equals their grace, but they just aren't aren't a very good choice for Arizona. If you want those big arched leaves (as opposed to fan palms), a good choice would be a date palm (Phoenix dactylifera), as they originate in a climate more similar to ours, although they are an oasis plant, so they will need irrigation.

Good luck with whatever kind you have.