Gardening in our Nation's Capitol

I came upon an interesting method of gardening last month on a trip to Washington D.C.  Take a look:

Here we are outside the Smithsonian Castle where the gardeners are at work on a sunny spring morning.

Apparently those purple flowers just aren't right for the site.

And those tulips should go too.

The end result: is it better?  Well, the soil looks very fertile and of excellent quality.  But, I really liked those cute purple flowers - they were in full bloom and looked rather perfect.  I wasn't the only tourist watching and wondering about our nation's gardening methods.  Would you do this in your garden?

I never found out what they eventually planted here since my plane was leaving...