You could do 3 trees in a straight line, 3 trees in triangular arrangement (2 back and one centered between in front) or 2 trees in a line. There's nothing wrong with the canopies touching and growing together (like a hedge) since you're trying to screen.

I appreciate the visual. I like the idea of doing a triangular arrangement, especially since I would need to plant anything a couple feet away from where the Aspen was removed. Do you think I could sneak a Serviceberry tree on the right side in the grass, and use narrow evergreens to the left of it (closer to the house)? Would that be visually appealing or are they too different to be planted that close together?

This is not a large space. I look at it as the creation of a screen that happens to be made up of multiple parts ... not as a collection of different plants that are closely planted together. If you are into variety at the expense of visual strength and clarity, you can mix plant varieties.

I would rather have balance so I just need to choose whether to do 1 (or 2) deciduous trees or a grouping of narrow evergreens. Thanks for helping me figure this out!

"Tree" is a vague word that doesn't narrow down size or specific form. You mentioned Amelanchier at the beginning. Why not 3 of those in a triangular arrangement if that's a small "tree" you like? It's not as if you're trying to create an arrangement where none of these "trees" touch each other. If you want evergreen instead, you could use Juniperus virginiana or something similar. I'm sure there are other species you could choose from as well, but it also depends on what's available locally. You might take the photo to local garden centers and consult with them.

I do love the look of the Amelanchier, I just hesitate that they will be too big at mature size, seeing that the width can be 20'. That's why I was thinking of only planting 1, or maybe 2. Three would be beautiful, but I don't want to overwhelm the whole yard. Good advice on taking a photo to the nursery, I was planning on doing exactly that!

I'd want something dense and constant like evergreen conifers - obvious example for your region Rocky Mountain juniper - so that the house eventually disappeared and was screened throughout the year (notice how you could still see it through the aspen, even when it was in leaf).

You're right,
Embothrium, conifers would eventually screen
that area. The area I would love to completely screen out is the neighbor
directly behind us. He is on a slight hill and has a nice view of the
mountains (looking past our house, and also a nice view at our windows), which
he doesn't want us to block. :(

Do
you think having 2 or 3 Amelanchier trees could create a sense of privacy or
are they too light and airy? I don't
mind conifers, just prefer the changing look throughout the year of something
like the Amelachier/Autumn Brilliance Serviceberry. Plus, I already have large conifers on each
side of the house in the front yard. I wouldn’t need screening
in the winter months, since I wouldn’t be out if the yard much that time of
year.

Can I just put in a word on behalf of the neighbours? If you plant trees to screen their house what effect will it have on them? Will you be blocking their sunshine? Shading their gardens? Causing branches to stretch over into the space? When one lives on a small plot cheek by jowl with others anything one plants in ones yard will impinge on next door. You mention that they don't want to lose their view of the mountains. Have you discussed the options with them? Will they let you into their home to look through their windows to ascertain exactly what they can see of your home and where a screen would be most effective?

The area where I will be planting will not have a negative effect in the neighbor's yard. It will bring some shade, but the shaded area is a dirt patch behind a swing set this is never used (high school kids now). They are aware that we are replanting in the same place where we had the Aspen removed.

The other neighbor (in a different direction) with the view will keep the view. :) I was saying that I wish I could block it, but I will be respectful of his quality of life. I just close the blinds. If there ever is a time when planting a tree is considered along the property line, I will bring him into the conversation. Good questions though!

While it is not the case everywhere, in the vast majority of instances, most neighbors -- probably easily more than 90% -- wish to have some privacy in the back yard, so it's quite common to screen or fence around property perimeters. Many people seem happy if either the neighbors do the screening or untended nature springs up an does it. In the US very few people consult neighbors about their intended landscaping projects. If neighbors are on friendly terms they will commonly inform each other of what's coming that's near the property line. Here in the US, people don't really have an expectation of trying to control what is happening on someone else's property. If they don't like what their neighbor did, they usually just grin and bear it. Of course, everyone has the right to control what comes from their neighbors as it crosses the line.

I am aware that there are cultural differences in attitude, Yardvaark, but I believe most plots in the US are much larger than over here. I am wondering how big your yard is? Mine is 15 feet x 25 feet. The concept of privacy is one which is extremely strong here, more so I think than in the US. Yards are almost universally walled or solidly fenced with clear demarcation of boundaries. Nobody would cross into an others garden without an invitation. Chain link is not used for domestic fencing because you can see through it. However, if my neighbour to the South planted trees along his fence my home would receive no sunshine at all - ever. My garden would become a pit of gloom and my home would be dark and miserable. It would have a seriously detrimental effect on my life. One's entitlement to light is an ancient easement enshrined in UK law. That is the sort of reason we try to come to a consensus on what we do along our boundaries. It would be selfish and antisocial to ignore the negative effects of one's actions on people living within feet of you. My neighbour to the north has recently put bamboo along part of his boundary after discussion with me. He was concerned that his patio overlooked us and put the screen in entirely for our benefit.

I live in N. CO as well. We had a similar issue and planted Spartan Junipers, which after 5 years are 9' tall. I wish I had planted more. They stay a pretty green all year.

Some trees will grow too tall and their trunks do not act as a screen. How about apple-less crabapples? Many have beautiful spring flowers and fall foliage and stay at a height that really acts as a screen. Multiples would also do well in tight area.

I agree that evergreens would be a great choice for screening, and I'm glad yours have worked out so well. I had originally passed on the crabapple idea because I was focused on looking at upright/narrow trees, and that didn't fit the bill. I do love them though, maybe I'll circle back to that idea and see if there's a variety available at the nursery that would work.

While yards here in the US have been shrinking for several decades, I guess they may still be a good bit larger than other places. Overall, people here are more concerned with privacy than they are with light as the latter is usually obtainable.

I visited the nursery and got recommendations for a couple upright deciduous trees. I'm not too familiar with either one, is anybody else? I still like the idea of planting 3 with the middle one off-set. The crapapple leaves are purplish and the cherry has green leaves. Would a mix of these work (2 crabapple with 1 cherry in the middle is my thought), or is it better to keep it as one unified look? Thanks. :)

1) Gladiator Crabapple - malus x adstringen 'Durleo'

2) Pink Flair Cherry - prunus sargentii

unified look.

That's a personal opinion. I think 2 + 1 would look fine. 3 different not necessarily so.

True. It's a personal opinion, but with several decades of studying such problems in a wide variety of situations, to support it. In evaluating planting arrangements, one style that I find often (but not always) tends to look amateurish is that of alternating plants. Two alike in the back row and a different type in the front is the beginning of such an arrangement. Why would we look at a complete screen as other than a single object ... especially because it is confined to a relatively small area (what amounts to a partial "wall" of an outdoor room)? To create it, multiple parts, closely grouped together, would be used. Why would that invite using dissimilar parts? Why would the driving force for variety weigh more heavily than the force for unity? That strikes me like how using 3 kinds of carpet in the same room adds "interest." Sure, it does. But it doesn't add sophistication and elegance ... or add an invitation for variety to occur elsewhere in a more meaningful way. We're not arguing about the functionality of the screen here but only about its appearance. I don't see how adding more variety to this single object improves the appearance of the overall yard.

Oh, I absolutely agree on the alternating thing. But if it is only 3 I don't see it as a pattern. If there were 4 trees and 2 of each that would be a pattern. I wouldn't regard the arrangement so much as a 'complete screen' or a 'single object'but as an attractive clump of trees which happens fortuitously to block a view. To me it would be a tiny copse, not a wall. The trees would not be in a row but in a triangle with the different one to the fore. For me a row of 3 identical trees is certainly unified but it is also potentially boring. To me a trio of 2 + 1 is also unified, but less predictable.

Maybe it's because I am a plant orientated person and a gardener rather than a garden designer. Many 'designed' gardens leave me cold as they show no feeling for the plants other than as 'material'.

Possibly there's also a cultural side to my preference. We refer to the land around our homes as the 'garden', Not as the 'landscape'. I think that says a lot.

I think with these 2 choices, the cherry is out (being too big to go with the other 2 trees), and I'll go with the 3 crabapples together. They are more compact and generally smaller in size, which I think is a better choice for being close to the fence.

The back of the yard is filled with color at different times of the year, so the backyard, as a whole, does have interest. Since these crabapples have bronze/purplish foliage, I may come back with questions on how to add bright green or bright pink around it. :) Thank you!

" ... but it is also potentially boring." But that's why there are other places in the yard and they require different things instead of a continuation of the singular screen. BTW, a screen has the duty of a wall. It visually and physically separates side-by-side areas. It is not a ceiling, floor or opening. (Later, it will become a ceiling, too, but that's not the reason for its implementation.)

I don't think the question of the exact word it's called -- a "garden" or a "landscape" -- makes much difference in what solutions work best, though it may indicate how people feel about their outdoor space. In the USA almost no one refers to their outdoor space as a landscape, but call it the front or back yard. The people who are plant lovers may call it a garden. But just as often as not, if one is really into plants (as many people here are) they tend to sacrifice appearance for plant acquisition, collecting and hoarding. I must confess I have no idea what "showing feelings for plants" would look like. To me, all the materials that are used in assembling a landscape ... are materials. Yet that hardly makes me (or many others) immune to appreciating their beauty when well put together and especially, for the plants when they age well.

I don't think the crabs are going to be any smaller than Amelanchier. 3 large shrubs (grown in the tree form) would screen the back neighbor's house. ... Lilac, beautybush, certain Viburnums, Burning bush ... that sort of thing.

Depending on personal preference, I think 3 different trees could absolutely work in your screen/border as well as 3 of the same variety. IMO, that would be preferable to 2 of the same and one different, but that's just my opinion. I'm not crazy about the alternating pattern for shrubbery. We have lots of trees in our yard (in CO also-- east of Boulder), some of them groupings and many individuals. I love Serviceberry trees for their beautiful foliage, fall color, and spring blooms. We have 2 single stem Robin Hill Serviceberries in our yard and 3 clump Lamarkii, and I've got a Saskatoon on my wish list for another area where we just lost an ornamental pear. I'm not sure they'd be the best choice for a screen though as they're pretty open and airy, but a grouping of 3 might give you a screen effect.

Have you considered Washington Hawthorn trees (or one of the other Hawthorn varieties)? They're one of my favorite trees for their all season interest, and have much denser branching than the Serviceberry trees so would give you more of a screen effect. We have a grouping of 3 of them along our driveway, in a similar staggered pattern as you're considering. I can snap a picture if it might help.

Thanks eastautumn. I'm in Longmont and have been to The Tree Farm a couple of times for their recommendations, which has pointed me towards the gladiator crabapple. I've also been to the very expensive Creekside Nursery. Are there other nurseries around that would have a different selection?

The Tree Farm definitely has the best selection of trees around here that I've found, but Green Spot has a decent selection as well (in southeast Longmont at 287 & 107th). The prices are great at The Tree Farm this time of year. You don't have buy even numbers to get them at half price either; we just got a Thornless Cockspur Hawthorne there for free because it was under $100 on sale and the Erie Tree Certificate covered the full cost. I'm not sure if Longmont has a tree incentive program like that.

If you're still considering an evergreen as part of the screen, I'd recommend a Black Hills Spruce. We have 3 of them in our backyard and they don't get as large as most of the spruces. They also come in various shades of green and greenish-blue. The Baby Blue Eyes Spruces are bluer but also smaller varieties. Or for something really narrow, there are Columnar Norway Spruces. We've got 7 of those throughout our backyard and they've also done well (we do have a drip line to water them). They stay pretty narrow, so you'd maybe want a grouping to get the screen effect.

Green Spot, I haven't thought about that one, thanks for the recommendation. At this point, I think I'm past the point of planting (who knew it would still be so warm, I keep thinking a freeze is bound to happen any day now). I may just jump on the Tree Farm sale next Oct. Thanks!

You can plant as long as the ground is not frozen.