Mike: I think a shadier location is best if you live in a very dry climate but they'd still need water at least once a week. The location you've chosen may work if only a couple of the leaves will be exposed to direct, hot afternoon sunlight; those sun damaged leaves could be pruned. If it's very dry in your area I think a deep drenching at least once a week (possibly twice) and possibly misting will be necessary until the plant is established. I'd also suggest mulching to keep the roots cooler.
We have very high humidity here in Florida and the Tree Philo's in our yard always got watered by the irrigation system twice weekly. Our tenants have not used the irrigation system in the 14 months they've been renting from us even though it's well water and doesn't cost them anything. The yard itself is now only sand and weeds and the Tree Philo's are fine but they've been well established for many years. Summer is generally our rainy season but some years we've been very dry and even in dangerous drought conditions but then we also have times when we are inundated with tropical storms or hurricanes that dump a lot of rain ... so it's very different from the climate on the west coast. Do you get frost and freezes in your area? We have frost and sometimes hard freezes here and the Philo's get knocked back and look pretty ratty (I think I posted a photo in the database showing cold damage) but once the weather warms up I remove all of the cold damaged leaves and they begin re-sprouting new ones quickly.
Hopefully someone from California will see this thread and have suggestions that might better fit the proper growing conditions in your area. I can only share my growing conditions here in Florida which is very different than what you have there in Ca and may not be of much help. The P. bipinnatifidum is one of the prettiest in my opinion and I hope your plant does very well for you.
Lin
