These 3 Butterfly Bushes were all planted the same day a few years ago. In past years they were about the same size although quite a bit smaller. The 2 on each end are the same variety (Asian Moon. The middle one is Pink Delight). Im just wondering why theyre such different sizes? This spring I cut them back about the same distance from the ground. On another note, 2 of my other BBs started rotting at the base. They did ok last year but this year they lost a few canes. My Black Knight looks like a 2-year old plant, small and spindly. The Pink Delight sent out growths to one side and the main shrub is sad looking. Should I just replace them? ( photo / image / picture from TheBip's Garden ) Moderator's note: added a more descriptive title to topic
Last year was much colder than most winters. I normally cut mine back in March and by then they were already sprouting new growth. I thought the cold had killed mine this year. They didn't sprout until April.
Just a guess, but warm air seeps through windows better than walls. Perhaps that is why the one closest to the window is largest and the one furthest from the window is smallest. It might help to mulch well before the cold weather hits and then feed them in the spring and a couple more times throughout the growing season. Do they all get the same amount of sun?
Is the one on the left the cultivar Black Knight and the one on the right is the hybrid Asian Moon? Those are two different plants, Asian Moon is a seedless hybrid and smaller (only 3'-5' wide) than both Black Knight and Pink Delight. The one on the left appears to be the only one enjoying where it is planted, even though it looks to be too close to the house. Since it's mature size is typically 4'-6' wide, it should be planted 2'-3' away from the house. From info I have found on line the Pink Delight is generally a larger plant (5'-7'tall and wide) than the Black Knight. And the growth only on one side could be explained by it also being too close to the house and not getting enough sun light on the back side. If the one on the right is Asian Moon then the size is probably just right for it's age. But it does appear to need more sun to fill out.
The big and small one are both Asian Moon. The big one is planted 3' from the wall, the small is 4' from the wall and about 3' from the fence. They all get the same amount of light.
These are the other 2 I mentioned. They start growing well, then canes (stems? limbs?) start rotting off at the base. This is my oldest Buddleia. Its around 8 years old I think. Last year was the first time I had problems with it. Black Knight ( photo / image / picture from TheBip's Garden ) This is my 2nd oldest. Same deal as above. Did well until this spring when canes started rotting at the base. The clump on the left is the original shrub. The clump on the right is what started growing this spring :/ Pink Delight ( photo / image / picture from TheBip's Garden )
Okay, confusion cleared up. 1 and 3 being the same bush I would think that you could dig #3 up and check the root ball to be sure it isn't girdling and killing itself. Some butterfly bushes are relatively short lived, so 8 years might be as long as you get. I can't find any definitive answer to how long they live though, other than some sites labeling them as short lived perennials. Is the new growth on the 2nd oldest coming from the original root ball or did the plant re-seed? The heat and drought took out two of mine in the back yard year before last. The one out front is about 7 years old and starting to show it. I think I will trim it back one more Spring and see what happens. If I have to replace it I am going to put out two Joe Pye Weed plants instead.
