Where can I purchase Barbary plants (Oregon Grape,etc) in Washington State?
I would recommend contacting your local nurseries or garden centers and see if they can special order these plants for you. However, I did find some leads on the internet that you can investigate and make your own judgment on:
The last two late springs it has had what looks like tiny grapes in little bunches but fall off. Anything I can do?
It sounds like it is a pollination issue. This plant does best with another of its kind planted nearby for cross pollination. They can self-pollinate, but most of the time, the plant will drop its fruit if it self pollinates. A second planting should help both produce full grown berries.
Whiteflies have infested one of my Oregon Grape Holly plants. How can I remove or repel them. But this may be complicated because I am on quite severe water restriction due to ongoing drought conditions and I don't use systemic pesticides in my garden. Is there any help in sight?
We recommend Neem Oil to treat Whitefly, and the good news is Neem Oil is organic. It's safe for people, pets and bees!
https://www.gardeningknowhow.com/ornamental/shrubs/holly/grape-holly-plant-care.htm
https://www.gardeningknowhow.com/plant-problems/pests/insects/whitefly-control.htm