I've been keeping reptiles for about 15 years, but never turtles. We recieved a turtle at my school recently that someone had found in an alley. I took it to the reptile store over here and they informed me that it was an Ornate Box Turtle, female, and adult. It is very friendly (not at all shy and pokes its head out further when approached). They gave me some info on keeping and feeding these guys, and I've looked up a bunch of care sheets; still I have a few more specific questions.
I'm in Southern California (I think our climate is pretty good for the turtle), and the turtle is currently outside in a planter about 20 ft by 2.5ft. It can't climb out, there's a lip. It gets direct sun most of the day, but has plenty of shade areas because of the lips and the plants. Only a portion of the planter has anything planted, tomato plants and a few corn stalks. Are these okay for her to be around? What other vegetation should I plant that she might eat? Will this be a sufficient size for her?
I'm going to set up a compost pile, both for keeping worms and such as well as for humidity. What is the best substrate to use, and what are the best bugs, worms, etc. to start building on?
Until we have any kind of natural breeding ground for food sources I plan on feeding her mostly whatever worms (red worms, nightcrawlers, silk worms, etc.) I can get around here. She also enjoys some fruits and vegetables, especially strawberries and apples, so I plan on supplementing her diet occasionally with that kind of thing. Any other proteim or fruit/vegetable sources I should add? Also, do I feed her till she stops eating, or should I limit her to a certain amount?
Any help you can give would be greatly appreciated, I'd like to give her a good home. Oh ... she will probably be going to the reptile vet soon, even though the pet store says she looks healthy and active, I just want to be sure all's well.
Here are some pictures. Maybe you can verify species/sex?


Eating




