The Crossing of the Danubes

Ageratum ‘Blue Danube’

Occasionally it happens: a slip of the tongue and you say the wrong thing; a slip of the mouse and you send the wrong email. In our case, we accidentally sent the wrong photo in our review of Ageratum ‘Blue Danube’. The photo we sent was of Stokesia ‘Blue Danube’—a fine perennial and a nice blue, too, but it’s no ageratum.

Stokesia ‘Blue Danube’

Both ‘Blue Danubes’ are dwarfs, about six to twelve inches, and they both bloom in the summer with a nice violet-blue. Both are types of asters. Travel south for half a day and both would be called perennials. Plainly they are similar. 

Ageratum ‘Blue Danube’

But they are different in an important way: presentation. The ageratum flower is the fluffier of the two, while the stokesia has a fuzzy bachelor button quality to it. Stokesia bloom individually and low to the foliage, whereas ageratums bloom in large clumping mounds that cascade over the tops of the plants.

Stokesia ‘Blue Danube’

This is the fun of gardening, because the two ‘Blue Danubes’ are so similar and yet so different. Diversity is part of the charm of a garden.