I've heard that hermans tortoises will it prickly pear is this true?And if so what part of the cactus should I feed him and how should I prepare it?

Prickly pear is edible feed the large pads, burn off the spines (if theres any) and chop it up.

You can also purchase it already prapared from some places.

ya, if you search google pre-prapared prickly pare tortoise food (it will bring many sites up you find one that sells it)

Thanks I read in a book they ate it in the wild and I want him to feel more natural.

can you grow this in southern california?

Josh you can grow prickly pear in most countries and states.

Prickly pear,also known as Opuntia cactus,is full of fibre,a good food source to feed in moderation as it can make the torts poo a little loose,abit like us eating Bran.Once the spines are burnt off,give it a rinse to clear off any stray spines.I only chop it up slightly when i feed it to my hatchlings.This way,it helps them build up the small muscles in the neck and legs when they have to pull at it.
Also worth pointing out that if you purchase these from garden centres,make sure that no chemical sprays or fertilizers have been used on them.If the chemicals have been used,re-pot it and leave it to weather for a few weeks.
I purchase my Opuntia cactus off ebay.Not sure of the regulations for sending plants overseas though,some countries dont allow it.

Hope this helps.

Look around. There are most likely plants growing around your area. San Diego has it all over