Most of the time when you hear the word “sport” you think of a game like soccer or baseball. In botany there are sports of another kind. Occasionally, a plant will develop a very different looking branch compared to the rest of the plant. Sometimes this branch has characteristics that make it desirable to nurserymen to propagate a new type of the plant. If they can get a cutting going and grow the whole branch out into a plant on its own roots or graft it onto a rootstock, they may have a new variety of the plant that can be propagated for commercial purposes. These sports are highly desired because of this.
An example of a sport that has become a popular garden plant is the dwarf Alberta spruce. It is a dwarf variety of a white spruce (Picea glauca). Regular white spruce can grow in the forests up to nearly 100 feet tall. With the sport, the distance between the branches is very reduced. It may only grow a couple of inches per year. A twenty-five year old regular white spruce may be about 40 feet tall and a dwarf one may stand only 5-6 feet tall. This reduced branch growth makes the little tree very tight and compact. It is a very attractive small landscape shrub and commands a good price for the grower.
The large branch winging out is a normal Alberta white spruce without the dwarfing effect.
The picture above was taken of a Dwarf Alberta Spruce growing in a cemetery where it has attained the height of over 8 feet. Since it is actually a white spruce, genetically, it has all the makings of a big tree. Only the small genetic change that occurred in the sport branch has dwarfed the plant. Plants and other creatures make mistakes sometimes in their cell division when the chromosomes split and sort and divide. It was a mistake that created the sport in the first place and after many years and cell divisions later, another mistake can undwarf it. This “big” branch coming out will soon grow and grow and begin shading out the shrub. It is a more successful form of the spruce so if the tree has a chance, it will send more nutrients and water and growth hormones to it at the expense of the dwarf part. If you want the shrub to stay dwarfed, it is important to prune out the reverted sport and keep the form dwarfed.
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