Hello from Toronto, Canada. Our blue spruce is 15 ft tall and 10 feet wide and we want to stop it from getting wider and taller. We bought it under the pretence that it was a "Fat Albert" but it is not so! What is the best way to prune & what month? Thank you!
Outside United States
Hello, and thank you for contacting us about your blue spruce. According to one major grower, 'Fat Albert' "grows 10 to 15 ft. tall and wide in 10 years; 40 ft. tall, 20 ft. wide in time." You didn't mention how old your tree is, but typically the sizes given in plant descriptions are the average size at ten years.
There is a limit to how much pruning you can do successfully on spruce. At best, you will only be able to slow the growth of the tree. At some point, you will need to remove it.
The practice of topping to control tree height is never recommended and results in a deformed tree. If the tree is too large to fit the space, it should be removed and replaced with a smaller species.
Generally, you can pinch back the growth of the new candles by half. This should be done in late winter or early spring. It slows the annual growth and encourages more dense branching near the cuts. If you cut into old wood, the tree will not develop new growth to cover the cuts and it exposes the tree to disease.
Thank you very much for your helpful response.
Our fat albert blue spruce is about 8-9 years old.