Hi- I am planting an area in my Redwood forested backyard and want to create a carpet like feel at the base using native oxalis oregana (I am in Seattle). A couple of questions, I seem to be getting mixed information on if this an evergreen or not (just curious if it dies back in winter). Also, to create that carpet like feel, what kind of spacing would you recommend? Does this plant fill in fast or is it slow to fill in. I believe I have the perfect setting/microclimate for this plant under the redwoods, dry shade, acid soil. thank you for any information you might have!