Is it safe to place Emerald Green Arborvitae next to house?

Question

I'd like to plant an Emerald Green (Thuja occidentalis "Smargd") about 2-3 feet away from my house's foundation, in the midst of a trio of redosier dogwoods. Is the proximity to the wall of the house going to cause me problems? I know it would be a definite no-go for something like silver maple, but I'm reading online that Emerald Green has shallow, fibrous roots and wondering if that's less likely to invade into the basement and damage the foundation?

Answer 1

I have read so much BS about trees damaging foundations that it's not funny. Almost all of this garbage is put out by people with a vested interest in you spending your money on their unnecessary services.

Tree roots follow the path of least resistance towards water and nutrients. If your house is on a slab, then there is no water under it because there's no way for rain to hit the ground under your house (there are exceptions, but that's due to a high water table and, sometimes, extremely poor grading next to a house). There is no incentive for the tree roots to infltrate under a slab. Tree roots also need oxygen and the soil under a slab is anoxic.

If your home has a basement that is NOT fieldstone, then again, there are no water or nutrients to attract the roots. There is also the issue of air-pruning the roots should they somehow make it through a foundation and into the basement. In these cases, tree roots will simply hit the side of the foundation and move parallel to it or away from it. FWIW, I had a house with a 90 ft tall silver maple 12 feet from the two foundations of different eras with NO issues whatsover (the original house foundation was poured concrete, the addition was brick and masonry on a footer).

A fieldstone basement (especially when not on footings) is a different matter entirely because those foundations are less stable than poured concrete or masonry and can be affected simply by the roots growing next to them; tree roots can indeed have an impact on them.

Many of the "experts" talk about subsidence caused by roots due to excessive water intake. This is frankly nuts. It will never be an issue with an older house and is NOT an issue with newer houses - in those cases, any subsidence is caused by the settling of the fill around the foundation, not by tree roots. If tree roots caused subsidence, then you'd see depressions around every mature tree in the world as their roots depleted the soil of water.

As to your arbor vitae, I have nine Emeralds in my side yard and, although their roots are indeed shallow, they also have an incredibly wide radius for such a narrow tree: in my yard, the roots extend nine feet from my four-foot wide trees. They should have a good root run to ensure that they're not stressed by too little water. If you want to try them next to your house, be aware that the arbs' MINIMUM mature width is four feet; they can grow up to five or six feet wide as they mature, with heights of at least 14 feet. They also typically have multiple leaders, so they'll be wide, not pointy at their tips. This will effect tree placement if you have a fascia/soffet because they can actually hit that on a one-story home.

Because you'll always want at least one foot between the tree and the wall of your house (to prevent damage due to branches hitting the siding and from fungus or root caused by the tree's branching resting against the side - a definite problem with evergreens), I'd put the minimum distance from the center of an Emerald to the house at 3.5 feet, with a preferred distance of four feet or more.