Trink's dug herself a bed in the (currently unplanted) flowerbed. I can understand why... the nice cool dirt probably feels really nice during the hot Texas weather.

Going on the basis that it's better to have one known spot with a hole (rather than having her dig new ones if I try and fill that one in), is there anything I can put in there that would make it more comfortable for her? Right now she's dug up the mulch and dirt, which means that she has to dig on the edges to get cool material in there. Would something like sand be a good idea? I'm thinking that a good layer of that would be diggable and cool once the top layer gets flipped over. And it would be easier to brush off her than the mulch.

Thoughts?

Letting her have a hole may be a good idea. You could try the sand, but it may tend to fill itself in. A wading pool is another good way of cooling the dog off. They can be a little messy.

Fighting hole digging is a lost cause. I don't have a solution and in all my years on the net, my reading, my training, etc. never saw anything that sounded good or saw any reports that somebody else's idea worked. My one puppy manual says we are not supposed to let them dig holes. I eagerly awaited instructions since Holly has been one of the worst hole diggers I have ever had. Well, their solution is supervision. Don't let the dog outside by itself. I have been very lax about that, and I am sure most pet owners wouldn't see that as a good solution.

In most cases if you do something to make one hole unattractive, they dig another elsewhere. If she sticks to the hole you have, your decision to let her have it was a wise one.

Just let her have the hole,if she wants too