Siberian Elm in yard
Hi CSU Extension
I'm a new homeowner and have a large tree in my side yard. I believe it's a Siberian Elm; see the attached photos. Its branches hang over both my house and my neighbor's house. A recent windstorm knocked down a pretty large branch that fortunately missed both our roofs. This branch had some obvious rot/disease to it and I was told that the tree had been treated/trimmed for disease before. I can see additional dead limbs high up that I fear could come down. However the tree currently provides terrific shade to my house and I'd hate to cut it down--but I will if I must.
Before I start calling arborists to come evaluate this tree, I'd like some tips about this particular species, whether it's ever "topped", if it's considered a nuisance/invasive/etc. species, and what questions I should ask of any arborist I have evaluate it.
Denver County Colorado
It's definitely an Elm and it may be a Siberian (Ulmus pumila), however the leaves in the pictures look large enough that it might be an American Elm (U. americana). If it's an American, it was planted a very long time ago - before Dutch Elm disease ravished the species - and so it may be very old and possibly reaching the end of its life. There are still many of these aging trees in central Denver neighborhoods and many of them have interior rot and dying branches. In either case, you definitely should have certified arborist evaluate the tree for safety issues. There is a 'find a pro' function on the International Society of Arboriculture website (http://www.isa-arbor.com/) and Denver Forestry has a list on their website of tree companies licensed to do business in Denver.