You will need to irrigate it regularly in Upland, Carlotta. It exists in Nature where there is regular ground water. I grow it in Encino and it DEMANDS regular watering like any other rose. You will find where it survives without it, there is sufficient ground water for it to eventually tap into. You should probably contact Grow Native Nursery, Rancho Santa Ana Botanic Garden in Claremont. Their site is linked below. They sell many plants which should be perfectly suited to your area. Good luck and have fun! Kim

Here is a link that might be useful: Grow Native

Hello Roseseek,
I adore their botanical gardens! It was a favorite haunt of mine. We did move, we are now living in Reche Canyon between Moreno Valley and Colton. Its wonderful here, the neighborhood is amazing and a true community.
I know Rosa Californica grows wild on Mt. Baldy, but always felt weird sneaking a cutting from there.
We have grey water drip irrigation set up, and I could easily divert some water for R. Californica (hopefully a few more)
Thank you for the great suggestions,
Carlota

I live very close to RSABG and visit the garden frequently. Some of my favorite plants are their CA native roses--of which they grow many (including various selections of R. californica from around the state). I have several different R. californicas that I bought at RSABG--the best being R. californica 'First Dawn' an introduction of Suncrest Nurseries from wild-collected seed. It blooms more profusely than all the others, is extremely fragrant, and sets hundreds of hips (that are the best tasting of all rose hips I've tried). Flowers are pale pink and cupped. It prefers a location with some afternoon shade/dappled sun. When established, it can do well on below average water in such a spot.

Grow Native Nursery Claremont is closed until the Fall Planting Festival on October 4 (the Westwood location is open year round). They usually have R. californica at the annual plant sale, the most recent ones have sold First Dawn.

Melissa

Here is a link that might be useful: RSABG Fall Planting Festival