I was wondering if anyone knows how long O. heterophyllus 'Goshiki' shrubs can live in the lower mainland area. I can't seem to find much info online about mature specimens and how long they can live. I'm working with one that is roughly 20 years old and it just suddenly dropped all its leaves. It seems to be budding out in sections with small flowers though (see photo). It was mulched with an organic blend in September and is about 8ft. from some parking spaces. Thanks.
I have no idea how long Osmanthus heterophyllus 'Goshiki' could live under optimal conditions but I'd be very surprised if it were only 20 years. Rather, the leaf drop you describe should be investigated from a disease and/or cultivation perspective. Diseases or insect problems don't usually cause sudden leaf drop in my experience. My bet would be that it is reacting to inadequate water, considering the recent challenges many areas are facing from lack of sufficient water during dry months. Although O. heterophyllus is known to be drought tolerant when established it appreciates occasional watering especially if grown in a sunny position. The OSU website states that this Osmanthus prefers: Part shade, prefers fertile, moist, well drained, acid soil, but tolerates higher pH soils. Osmanthus heterophyllus 'Goshiki' | Landscape Plants | Oregon State University Can you say if it was provided with occasional water during dry periods? That may be an important clue. It's hard to tell from your photo but I suspect some of the branches not sporting blossoms may be dead. Using either your fingernail or a knife, try scraping away the surface bark and see if the cambium layer beneath is still green. If not, you could presume the branch is dead. Having said that however, you should wait a few months to issue a death certificate because you never know where new growth may appear. At that point, you could prune out any dead branches. It may be knocked back but likely not dead; I think a little more TLC going forward will ensure this beautiful shrub will survive the trauma of its recent leaf loss.
It never got water during dry spells as far as I know and it's mostly full sun. Yes the non blossoming branches are brittle and dead. It's in a bed with 4 other 20+ year old shrubs that have done well with zero water in the summer and it looked great in the fall. I wasn't thinking lack of water but I agree given the recent summers. There does appears to be a good portion of living branches so there might be hope.
