You realize fruit trees are extremely hard to grow. You will need to spray them on a regular basis for any chance of edible fruit. You will have to wait at least 3 years for any fruit. The number of fungi, and pests that attack the trees and fruit is pages long. The only fruit trees I can think of with little care are Cornus Mas, and Serviceberry. Both can be grown in partial shade. Cornus Mas or The Cornelian Cherry is very tart, and cannot be eaten raw. Serviceberries can and taste like blueberries sort of. Northline is a good variety. Both can take some shade.
Cherries, peaches and other stone fruits need a lot of attention and more light. I can't think of any cultivar that is OK in shaded areas? A good cherry tree is White Gold. It will grow well in your area. Self fertile too. For peach trees many exist that are good. They may grow in that less of light, not sure how well though? You could try. But you must spray these trees a lot, and pruning them properly is extremely important.
You could go for a huge bush like say Elderberry. Ornamental, little care, but fruit also has to be cooked. You cannot eat them raw.

To get an idea of what you need to do look at the posts in the fruit and orchard forum. You also may want to ask there too.

Good advice from Drew....think first before you make a mistake of which tree you and your neighbor will have to deal with.

Fruit trees are notoriorsly dirty things....they drop leaves....and fruit....and otherwise dirty up the base around them. Unless you expect to keep the area underneath clean at all times....think to grow something else.
Lawns especially have a tough time trying to grow under trees....and where sun is at a premium, you are just putting your yard in danger of never being green.

Before you decide which fruit tree....visit a couple local orchards; talk to the orchardman...ask his assistance on how to, what to, when to.....grow a fruit tree.

So what did you decide and how is it going?

Hi Drew, thanks again for this great advice.

I think we're going with the Pawpaws, I've printed out some documentation to give the my neighbors but suspect they'll be on board with whatever I recommend. Probably one grafted & the other seedling, one for each side of the fence.

I've not been able to find pawpaws in the GTA, the closest place I've found so far is Niagra;

http://www.grimonut.com/catalog.php?catID=70

It's part of a project, we've also redone the interlocking near where the trees will be after some basement flooding issues last year. Slow & steady :)

Pawpaws are great in the sense they like shade, and really need no spraying. A rare thing! You could mail order one, but it would be very small. Other trees like peaches grow so fast that matters little. Best to get a small one. I no nothing about pawpaws except at my cottage a friend has a couple in his yard, and I steal the fruit from time to time:)

The fall is a good time to plant them.
Stark brothers is a decent nursery and has some for sale via mail order. 5-7 years to bear, must be rather small...
What's cool about Stark Brothers is they have growing and care guides, check that out. They tell you the basics of everything you need to be successful from start to finish!
Look under one of the varieties and you will see a link for plant manuals. Very cool!

Here is a link that might be useful: Starkbros. pawpaws

This post was edited by Drew51 on Mon, Jul 15, 13 at 13:13

I did check out Stark bros, I will use the Plant manual for sure.

Best for me to order a local variety though, since I'm in up north I'd like the strain that native for my area, it's possible there's a difference.

The pawpaws will join some other plants I've transplanted from my childhood home in northern Ontario. Just this weekend I savored some raspberries that taste quite unlike the store bought varieties - they brought an instant flashback to my childhood, in beautiful abandoned farm fields.

This post was edited by PaulGTA on Mon, Jul 15, 13 at 14:38

Good idea to stay local, but I would think any pawpaw rated to zone 4 would grow there. I'm growing pluots and nactaplums from the California breeder Loyd Zaiger.
I just made fruit leather from my strawberries and raspberries. I made Yellow raspberry leather, well it's in the oven as i type! I bought some kiwi's and made strawberry-kiwi fruit leather. i used pineberries, alpine, and regular strawberry blend. Now to bake for at least 3 hours. The strawberries were done first. I never made it before, and so this is an experiment. So far so good. I planted about 15 new raspberry bushes this spring. I had one, Fall Gold that is 3 years old. This is the summer crop. I expect a fall crop from them too. I should also have a fall crop from the everbearings I planted. I also planted summer bearing, and a bunch of blackberries too. Berries are easy to grow and rewarding. I planted a couple of red currant bushes too. I want to add more this fall. I have to find room, but I'm having a ball with these fruits!
Here's a photo of my yard