Hello,

Yes, Arborvitae have central leaders but some have many stems growing from the roots. It all depends on the cultivar. Arborvitae do not form new buds from old wood so you cannot prune back to old wood and can reduce each branch by one-third only. Read about arborvitae here: https://libguides.nybg.org/arborvitae

To reduce height, prune in late winter by removing the central leader by 1/3 and pruning back vertical shoots to maintain its pyramidal shape. This will encourage another side branch to take over as central leader. It also can be sheared flat across the top and wider by at least 6 inches at the bottom. This type of formal shearing would probably have to be done up to three times a year to maintain this appearance.

Read more about how to prune arborvitae here: https://mortonarb.org/plant-and-protect/tree-plant-care/plant-care-resources/pruning-evergreens/#!

And here: https://www.gardenatoz.com/what's-up!/big-mistake,-big-lesson/arborvitae-too-tall/#overall

I hope this helps with your trees.

Thank you for contacting Ask Extension.