Carpinus betulus 'Frans Fontaine' is a possibility. Pretty much problem-free and a great screening tree. Maintains a pretty narrow profile, much like the pear (but a scosh narrower).

Thanks that was the top contender but it's in the Birch family.

I'm sorry Hornbeam is a Beech. My wife is allergic to both Birch and Beech.

Actually, Carpinus IS included in the birch family (Betulaceae) but it is NOT a birch. Beech is in an entirely different family (Fagaceae :-) But both are heavy pollen producers so understand the need to find some that may be less of an allergen.

Your alternatives list has kinds that do not have the Callery pear outline at all. If you are willing to browse the list at the link below there are multiple selections on it that do have the more or less compact and upright shape that you may have been indicating is what you want. Some of the maples for instance. While they are a wholesale company you will be able to find various examples of their offerings at retailers here and there.

http://www.jfschmidt.com/introductions/index.html

Idealy they would branch out at 8 ft

==>>> trees are pruned to the height you want them .... or you buy them that way .......ken

Yoshino cherry is a pest and disease magnet, won't last more than 15 years. Look at cercis canadensis and some of it's cultivars ('Royal White' has white flowers in early spring), also look at crepe myrtles ('natchez' would be good for this).

Are you saying the mature width needs to be 8' wide?

Perhaps you have more than that but I really like Prunus sargentii Pink Flair. This particular species is one of the best in the genus. Blooms, great fall color and interesting bark sheen/color.

https://www.jfschmidt.com/introductions/pinkflair/index.html

Tilia americana, Diospyros virginiana, Cladrastis kentukea

All attractive trees not closely related to the trees your wife is allergic to. As insect pollinated trees, they should have less wind born pollen.

First and third grow much larger than flowering pears.

I'm still undecided on these trees. Thought if I added some photos of the area that might spark some new suggestions. Again I live in 7a (Southern CT) I have 140ft along a fence line that I would like to plant 6-8 trees 25'-40'(mature height) 20'-30'(mature width). I can't plant birch, beech, and hazelnut due to allergies and would like to avoid the issues with Pears. I am leaning towards maples but worry about size and surface roots. Thanks for any help/suggestions.

Maybe try this.

http://hort.uconn.edu

What about 'Autumn Blaze' freeman maple? If you want something that flowers, maybe look at 'Winter King' hawthorn.

Redbud (Cercis canadensis) or Crabapple (Malus), though you will want to be sure to choose a crab that is disease resistant. I like your idea Yoshino cherry and tupelo/blackgum (Nyssa sylvatica). Do you feel the need for just one species, a more formal look? If you choose a few kinds you will have different plants providing interest at different times - flowers or fall color - and different growth rates and leaf textures.

No ornamental fruit! Redbuds are nice, but I would consider them small trees, not "medium".

Redbuds get to 25 feet, so within YG's size range. And to YG, Logan has a bee in his bonnet, based on not a lot of experience as far as I can tell, about ornamental crabs and cherries. I and many other posters have tried to convince him, unsuccessfully, that not all crabapple or all cherries are worthless. I'll let you decide if you will get enough pleasure out of the flowers, along with visiting pollinators and birds, to make them worth planting. There are some glorious photos of yoshinos on this thread, including several down near the end. I have very much enjoyed our cherries, crabapples and apples.

Well, I suppose if you want to replace them every 20 years or implement a spraying program. With ornamental fruit, it's like choosing how you die. Get pushed off a cliff or shot in the back of your head? Either way you end up with the same result (unless, I suppose, you're a mountain climber, or in this case someone who will constantly spray and upkeep the trees). While I have lots of disease-prone plants (such as roses) they are easy to prune, spray, etc. Unlike ornamental fruit, because when they gain some size, they are hard to maintain. Not that I am completely against them, I have a prunus subhirtella and a prunus salicina. The prunus salicina is dying, has gummosis, and is starting to leaf out now after it's sparse bloom. It is destined either for death and a chainsaw, or hard pruning and lime sulfur. I'm probably going to attempt to save it, but I don't have high hopes. The prunus subhirtella is a recent transplant, and is beginning to leaf out. It has been treated with sulfur and copper fungicide, and is growing rapidly because it died back to a stump. It's a seedling, so I expect it will get 30-40ft tall.

Prunus Salicina:

My Landscape · More Info

Prunus Subhirtella:

It has grown since I took this picture, and I will go and get some more when it stops raining.

What about paperbark maple?

Paperbark maple would look nice in that spot. I have never grown it, and have rarely seen it in person. I'm sure one of the other members could elaborate on it quite a bit. I do know that they are similar to japanese maples, but instead of having maple like leaves, they are shaped more like boxelder (which technically is a maple) or poison oak/ivy. It's called a "trifoliate" maple. I know if I could find one, I would definitely get it.

Serviceberry looks a lot like ornamental pear, without the same problems as the pear.

Logan, could you please just stop with the war against Prunus and Malus. You have had bad luck with them in your area. OK, we understand that. But the world is a big place and your experience is very limited.

At this time of year the ornamental cherries are in full bloom where I live. They never need spraying and remain healthy and disease free. Their life span is not as long as an oak tree but 50 - 70 plus years is plenty for most people given the glorious sight of a cherry in bloom. They are a sine qua non in our parks and gardens.

I would just say maybe a small, and perhaps unusual Japanese maple. I was going to say Redbud, but everyone beat me to it, and for all I know they may live about 10 years... I've never had one.

I like the paperbark maple, serviceberry, American Smoketree, and redbud suggestions. All smaller then Bradord pear.

Redbud are beautiful but tend to be short lived. However, a lot of people who have trouble with them live in colder climates...the fancy cultivars can't take as much snow as you would think from the labeled zone tolerances. You should be fine on that front.

What about Winter King Hawthorn?

What is it about ornamental pears you like.

Thanks everyone for the great feedback. I like a
very formal look using multiples of the same tree. Would love to pleach Hornbeams but my wife is
allergic. We have a couple rows of boxwoods in the front yard and the
monochromatic look appeals to me. Some
may think it’s boring but you like what you like. I like the overall size and
shape of pears as well as their dense canopy and interesting fall color. These trees will provide screening for 3
seasons. I do like the redbud,
serviceberry, and paperbark maple suggestions.
I will be hitting a couple nurseries this weekend as they are just
getting the new spring stock here in CT.

I believe that pleached hornbeams would be unlikely to flower since they are pruned every year. But they would look totally unlike a pear in shape. Also the tree is monoecious so if you could get female trees there would be no pollen. I don't know if that is possible. Perhaps someone else can opine.

Maybe some holly, american or english holly. They can be sheared while kept as trees, and it looks nice. I like a formal look, too. I haven't yet done pleaching. You could plant some american sycamore, and pollard them when they reach a desired size.

Paperbark maple in a row could look fantastic with it's wonderful branching structure. You could certainly achieve a pleached effect.

I don't know about a "pleached effect" but it would look nice.

That paperbark maple looks nice!

But have you thought of dogwood? Maybe too small but they are lovely.

I'm partial to Japanese maples, and there are so many varieties, some quite unusual and some with variegated leaves. Many different size to choose from as well. I see there are some big trees behind that fence of yours, and Japanese maples often do particularly well when planted near larger trees.

Do Chinese pistache trees grow in CT? They are GORGEOUS and look like they're on fire in the fall. I'm partial to the variety that produces the red berries after the leaves drop -- so interesting! Maybe it's a bit bigger than what you want, though.

And then there is the Wointer King Hawthorne to consider. It groes to 30 feet.

Crape myrtles are usually thought of as southern trees, but I've seen one growing in Newport, RI. Lots of different colors to choose from there, but beware that some have a more upright growth habit, so be sure the one you get has a more spreading growth if that's what you want.

Nothing goes with a formal look like beech...