Hi, I have a very similar situation. See my thread concerning trees for my backyard. I can however tell you the following.

Determine how tall you need to screen your yard and then figure out whether you need a tall shrub or a small tree. It all depends on the neighboring views into your yard.

Also best to purchase a fairly grown plant but that can get very expensive.
Ianna

A hedge can be made out of trees. A hedge is usually either trees or shrubs planted close together and then maintained at the chosen size by frequent shearing. They are labour intensive.

An informal row of shrubs or trees can be used with less work. Remember that most shrubs get about 2/3 as wide as they get tall, so an 8-10 ft high shrub border will take up 5 to 8 feet deep planting bed. If you have a small backyard, you may be giving up a significant amount of lawn area to shrubs.

Also check the direction. If your yard is north of the fence, the hedge/trees will create shade all day.

Think carefully about why you want the extra height. Do you really need to screen that much view? A regular height fence (5-6ft) will provide privacy from your neighbours when they are in their yard. If you want to screen view from the bordering house's second story windows, think about how often anyone will be looking out--how often do you sit staring out your bedroom windows at your neighbour?

If the fence is wooden, maybe an 18 to 24 in lattice topper would suffice. Or a small tree with dense crown planted close to the patio?

As you'll see in Ianna's thread, there aren't that many short trees to choose from :-)

Trees also tend to have a fairly wide crown and will have to be planted at some distance from a fence to avoid damaging the fence as it grows. If they're planted too close they could also eventually shade your neighbour's yard and that could cause problems down the road. If you have the space then a couple of cherry trees, flowering crabapples, Kousa dogwood or even magnolias ($$$) are some of my favourites.

If I wanted only a couple of additional feet of height and space was an issue, I'd use a lattice topper like Judy mentioned, but if you really want plants there, Maybe you could use a trellis and plant some climbing roses too.

If space is not an issue, then there are tons of shrubs like forsythia, lilacs, mock orange and spirea that will grow to a decent height and provide some flowers and scent as well. They're all fairly easy to care for and easy to find.

Another things to consider: do you want something that will screen in the winter as well? Then you'll want some sort of evergreen plant. Cedars are the usual choice for that sort of situation (fairly fast growing and not hugely expensive) and they can be planted fairly close to a fence. Yew is another option, as it is very prunable, but it is a slow grower.

BP

Why not try a Japanese Lilac, a Redbud, an Emerald Green Cedar, a narrow variety of crabapple with a combination bulb garden in the spring under the deciduous trees progressing to shade perennial and ground cover garden for the remaining year.
Sharon

I noticed the other day, at home depot, in ottawa, they had 7foot Junipers on sale for 20.00. I didn't look too closely, because I don't need them, and I have a bad habit of not being able to resist a good deal, especially if I don't need it!!!
But they looked really nice, and they would make a nice screen, if you like Junipers. I would assume they might have the same kind of deal in Toronto.

Hi I do have cedars but I wasn't planning to a very dense screen but simply an airy kind of screen. With full grown cedars it would look too confining in my small yard. I have my cedars shielding only the shed from view.

I am doing a tree mix of sorts. A tall and yet unidentified tree, suitable to the backyard, together with small trees & shrubs, my redbud (too small yet), lilacs hydrangeas, - so what I am aiming for is foliage mix... I like the idea of the Japanese false Lilac, I've now discovered the beauty of a pagoda dogwood. I may even try an ornamental pear tree.

Anyway, I pretty much know more or less some tree varieties to try in the yard.

Incidentally, I went to Home Depot and purchased an apple tree to espallier. Have it down to a 3 ft height and am now training the branches to grow low and sideways.

Ianna

I need a tall tree to screen a two story house next door a row of about 60 feet long but I would like tidy trees as we may but in a pool some day ! Other problem is I need it fast growing , Is there such a tree? Please help!