As reported by WashingtonGardener magazine:
If you've never been, take my word for it that the azalea collection is stunning in bloom. Stunning. And, honestly, seeing car loads of people flocking to the National Arboretum is a rare thing (I've been there almost every Saturday for a year taking classes. The parking lots are rarely full.). Plus, in this day & age how many people do you know that take precious weekend time to go out and look at plants? I've seen kids there romping around, excitingly calling out the different colors as well as more elderly folks searching for their favorite.
Consider contacting the people listed at the bottom of the article to save the azaleas. The collection really is a national treasure!