The impact of container size on Green Giant Arborvitae

The picture below shows two Green Giant arborvitae. The one on the left is in a 7 Gallon container with plenty of space between containers and is 4’ tall. The one on the right is in a 3 Gallon container and is 4’3” tall.

The one on the left is about 6 months older and the measurement of the trunk size clearly would show it to be more mature.

Tree shape can be influenced with cultural practices, although tree maturity can not. So, by growing the Green Giant Arborvitae in 3 Gallon pots and stacked close to each other, they will stretch in height, although they will remain skinny. Growing them in larger containers (& shearing them) will lead to much bushier, although less tall trees.

It appears that the small container size and thereby the constrained root volume stresses the trees to gain height faster and thereby leading to a faster tree maturation and potential reproduction.

So, when buying trees, the container size of trees is a much better indication of tree maturity than the height. Of course, ultimately the tree ‘caliper’ or trunk diameter will show the true age of a tree.

As for the two trees in the picture below, the one in the 7 Gallon container will put on more growth in late Summer and will be sold. The one on the right will be re-potted into 7 Gallon in the coming weeks and sheared to gain some lateral density and delivered to customers in the Fall.