We have this tree in the backyard and we are not sure if we should let it thrive.
When it started growing (on its own) we thought it was a sumac and we were fine with that.
But now it’s much taller than that, we have not seen the red clusters typical of a sumac and, as you can see from the pics, very close to the house.
We don’t know what it is and if we should let it grow so close to the house.
We like the shade it provides to the deck
PS: located in kitchener, ON, shade in the morning and full sun in the afternoon, clay soil.
The tree that has sprung up in your backyard is Ailanthus altissima or “tree of heaven”, also occasionally referred to as “Chinese sumac” for its resemblance, as you mention. This is an invasive species which grows quickly and liberally self-seeds. It is impervious to bad soil, to drought, and to pests. Ailanthus altissima can be very difficult to eradicate because it can also reproduce quickly from any piece of root that remains in the ground. Here is a blog post that takes a gentle look at this invasive tree (including a good picture of a small seedling): https://www.torontogardens.com/2009/06/warning-dreaded-ailanthus-altissima.html/
The Toronto Master Gardeners have received many questions about this tree – specifically, how to eradicate it. This is not an easy task, but you should consider removing it for a couple of reasons: first, its location is indeed rather close to the house and they do grow to great heights (hence the second part of the name, “altissima”) and secondly, they reproduce so prolifically and are so fast-growing that you may find your garden inundated with them.
You are best to remove this tree by digging up as much of the root as possible and being vigilant about removing new saplings as they appear from pieces of root that may have been left in the ground. Cutting the tree down will only encourage suckers at ground level. If you google “Toronto Master Gardeners Ailanthus altissima” you will be able to read several posts on this tree. Here is some good basic information about this invasive species.