Planting arborvitaes near existing tree

Arborist Forum

Help Support Arborist Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Bern41

ArboristSite Lurker
Joined
Mar 22, 2016
Messages
12
Reaction score
1
Location
Atlanta
Hi, this is my first post on here so I hope I have the right forum. I bought 8 greengiant arborvitaes to plant along a fence in my backyard. There are a few oak trees already there. First one went in the ground about 6 feet from nearest oak. I only encountered a couple roots when planting that one, nothing more than 2" diameter, so I just cut through them to make room for my green giant. Next tree is 6 feet further down from the first and after digging a hole I'm seeing a somewhat dense root structure. About 5 roots, up to 2" thick (see pic). Now, these could be coming from a tree that we recently took down or a neighbor's tree that was recently taken down. Or they could be coming from the oak, or possibly even a much smaller tree in front. My question is whether I should be safe in cutting out these roots from the hole and plugging the green Giants in? Thanks
 

Attachments

  • image.jpeg
    image.jpeg
    2.8 MB
I've put literally miles of privacy fence up over the last 40+ years. We drill either 8" or 10" holes, 3' deep, and set the posts in concrete. I've cut through roots as big as 7" in diameter, and as many as 4 or 5 in a single hole that were over 2" diameter (anything smaller I can chop right through with a sharpened drain spade) but I've worn out several reciprocating saws and hundreds of blades doing it. Never once, in all those years, did I manage to kill a single tree or shrub. No partial die offs, sudden changes in health, nothing. You can take that with a grain of salt, and I'm sure that dire warnings will ensue... but I'm telling you my personal experiences with cutting through roots in those size holes, at that depth. When planting landscape trees and shrubs, I try to just remove the dirt around the larger roots and plant the new one in there with them, or just move the new planting over a little and try again. I've had to move the hole 3 or 4 times trying to hit a spot where I do the least damage to existing roots, but believe me... there's a point where I plop them in the ground and cut any roots that are in the way. I have had new plantings that didn't do well, but again, never killed its neighboring/existing plants or trees.

It is my personal opinion that if you're seeing that many roots, the odds of their owners having a weak root system except in that very spot are astronomically slim. You'd have to cut an awful lot of them to kill anything.
Having said that, I wouldn't cut everything in the hole. Just cut them if they are stopping you from getting the hole deep enough, or from getting the new tree in there. Big ones, try digging the hole away from them if you can fudge the final planting spot a bit. Basically, enlarge the hole in some direction where you don't have to cut any more than necessary.
 
I've put literally miles of privacy fence up over the last 40+ years. We drill either 8" or 10" holes, 3' deep, and set the posts in concrete. I've cut through roots as big as 7" in diameter, and as many as 4 or 5 in a single hole that were over 2" diameter (anything smaller I can chop right through with a sharpened drain spade) but I've worn out several reciprocating saws and hundreds of blades doing it. Never once, in all those years, did I manage to kill a single tree or shrub. No partial die offs, sudden changes in health, nothing. You can take that with a grain of salt, and I'm sure that dire warnings will ensue... but I'm telling you my personal experiences with cutting through roots in those size holes, at that depth. When planting landscape trees and shrubs, I try to just remove the dirt around the larger roots and plant the new one in there with them, or just move the new planting over a little and try again. I've had to move the hole 3 or 4 times trying to hit a spot where I do the least damage to existing roots, but believe me... there's a point where I plop them in the ground and cut any roots that are in the way. I have had new plantings that didn't do well, but again, never killed its neighboring/existing plants or trees.

It is my personal opinion that if you're seeing that many roots, the odds of their owners having a weak root system except in that very spot are astronomically slim. You'd have to cut an awful lot of them to kill anything.
Having said that, I wouldn't cut everything in the hole. Just cut them if they are stopping you from getting the hole deep enough, or from getting the new tree in there. Big ones, try digging the hole away from them if you can fudge the final planting spot a bit. Basically, enlarge the hole in some direction where you don't have to cut any more than necessary.
This is great advice and sets my mind at ease
 
I've put literally miles of privacy fence up over the last 40+ years. We drill either 8" or 10" holes, 3' deep, and set the posts in concrete. I've cut through roots as big as 7" in diameter, and as many as 4 or 5 in a single hole that were over 2" diameter (anything smaller I can chop right through with a sharpened drain spade) but I've worn out several reciprocating saws and hundreds of blades doing it. Never once, in all those years, did I manage to kill a single tree or shrub. No partial die offs, sudden changes in health, nothing. You can take that with a grain of salt, and I'm sure that dire warnings will ensue... but I'm telling you my personal experiences with cutting through roots in those size holes, at that depth. When planting landscape trees and shrubs, I try to just remove the dirt around the larger roots and plant the new one in there with them, or just move the new planting over a little and try again. I've had to move the hole 3 or 4 times trying to hit a spot where I do the least damage to existing roots, but believe me... there's a point where I plop them in the ground and cut any roots that are in the way. I have had new plantings that didn't do well, but again, never killed its neighboring/existing plants or trees.

It is my personal opinion that if you're seeing that many roots, the odds of their owners having a weak root system except in that very spot are astronomically slim. You'd have to cut an awful lot of them to kill anything.
Having said that, I wouldn't cut everything in the hole. Just cut them if they are stopping you from getting the hole deep enough, or from getting the new tree in there. Big ones, try digging the hole away from them if you can fudge the final planting spot a bit. Basically, enlarge the hole in some direction where you don't have to cut any more than necessary.

Also depends on the species. some are more sensitive than others to having their roots mucked around with.
 
Not sure if the oaks or arborvitaes will suffer the most. Arborvitaes planted under mature oaks are probably not going to work out well as they need lots of sun. In addition to books I'm also basing my opinion on my neighbor's experience. He planted them under the canopy of, and on the north side of, one of my mature chestnut trees... they look terrible 5 years later. The ones near the edges of the canopy have bent to the side to grab more sun. The ones directly under the chestnut are stunted with very thin foliage. Many of them have also had leafminer attacks. His home center landscape designer/installer sold him a lot of stuff but not the right stuff!

To make matters worse, because the arborvitaes were doing so poorly he hired an apparently untrained tree service guy to prune my chestnut tree "to the property line." The pruner left a bunch of stub branches that died.

Some people should stay in the city. Alternatively they need to educate themselves to know that planting sun loving plants on the north side of a mature tree and under its canopy is not a good idea. He was also not smart enough to realize that his roof full of new solar panels are also on the north side of my mature chestnut tree so they too are shaded quite a bit!
 
Back
Top