Knowledgebase
Downsizing Arborvitaes #745950
Asked April 23, 2021, 5:26 PM EDT
Charles County Maryland
Expert Response
Arborvitae (Thuja) will withstand heavy pruning and shearing because new branches develop from concealed buds in the branch crotches. Prune in early spring or mid-summer.
- When heavy pruning is necessary, prune before new growth begins in early spring so that new growth conceals pruning cuts.
- To lower the height (no more than 20 percent) of a plant, cut back to a lower branch crotch, making cuts only into live wood. To regain the natural shape of the plant, balance lower limbs by lightly pruning branch tips.
- Older arborvitae growing in shade will develop a dead zone that is incapable of regenerating new growth. Do not prune into this area.
- Oriental arborvitae (Thuja orientalis) is slow growing and responds best to shearing new growth only.
Hope this helps.
On Mon, Apr 26, 2021 at 2:40 PM, Ask Extension<<personal data hidden>> wrote:
Unfortunately, there is no way to permanently stop a plant's growth. If you want these plants short, you will have to prune them every year. This is a good example of the need to do research on plants before you buy them to find out their mature size. It appears you have the full sized variety, Thuja occidentalis, native to eastern North American which grows to 20-40 feet. If you decide to take these out and want to plant Thuja occidentalis that stays small, here are some suggestions: 'Little Giant" grows to 4 feet, "Skinner Dwarf' grows to 7 feet, "North Pole" grows 10 - 15 feet.
On Mon, Apr 26, 2021 at 5:18 PM, Ask Extension<<personal data hidden>> wrote:
They won't immediately die if you take off more than 20%. But they will look scalped. It will make them the height you want, and maybe it will take longer for them to get to their natural size but it will stress the plants. If they keep getting stressed, they will stop growing, as per your original question, but that means they will eventually die.
On Tue, Apr 27, 2021 at 6:14 PM, Ask Extension<<personal data hidden>> wrote: