I was so impressed with ageratum ‘Tall Blue Planet’ for the first couple of years that I grew this annual from seed.
The blue-violet flowers were a refreshing change of cool color in the back of the annual flower border where the warm yellows, reds and oranges of zinnias and marigolds reign.
However in 2013 and 2014 my plants never reached their promised height of 30 inches and got buried by other plants. In 2015 I even tucked them into the middle of the border instead, but that year my plants grew 10 inches tall and stopped. Unless some bees were able to find the flowers hiding under all the other plants in my crowded flowerbed this ageratum was merely taking up valuable growing space.
This year I gave up and went back to the old standby, ‘Blue Horizon.’ The seeds are harder to find, but the plants stand proudly in the back row of my flowerbeds like they’re supposed to.