According to their website, the "National Garden Bureau is a non-profit organization that exists to educate, inspire, and motivate people to increase the use of plants in homes, gardens, and workplaces", and they've been doing just that for 100 years!
One program they promote every year is the All-America Selections. AAS is the oldest, independent testing organization of flower and edible varieties in North America. Every year, they judge the garden performance of new varieties planted in trial gardens across the country. For more information, check out their website.
Every year, in addition to showcasing the AAS winners, NGB also picks one type of plant in several categories to feature in their educational efforts. In 2020, there are five types of plants: