I live in Toronto,

I let nature handle it. I see plenty of yellow jackets/wasps, bumble bees, mason bees, and sometimes hummingbirds and I don't do anything to attract them. I just don't spray any pesticides until the trees are done flowering.

kokos:

You might want to try getting Manson bees started in your orchard. You will need to study their needs and probably buy starter bees. Bumblebees work very well in my greenhouse for all kinds of fruit. They are very hard workers just like Manson bees. You can buy hives suited for outdoors. One hive lasts for 8 weeks for me, longer than needed.

Agree with homer
Most likely you have no problems in getting fruits, when I got my honeybees, I couldn't see any different in pollination. [Guess my wild bee population is still good] If you're fond in working with some bees, go with Mason,.. low maintenance. To take care of European honey bees takes allot more
time and effort.

Konrad

I live in a city and the backyards are close to one another. I have a big back yard. I would like a few bees for the bloom period.

I've read various sources that Mason bees are the better pollinator due to:
1) They are sloppier with the pollen they collect in hairs on their lower abdomens which drops directly onto the middle of the flower when they land. Whereas honey bees pack it neatly into baskets near their hindquarters.
2) They fly during drearier weather.
3) They do not fixate on alternate pollen sources.
4) The visit more flowers per hours.

I can vouch for #1. #2 I think is overstated. My observations is Mason Bees stay "indoors" on cool or wet days as much as Honey Bees do. #3 and #4 I don't know.

What I will say for sure is that keeping mason bees would be easier than honey bees. Smaller numbers, no stings, no diseases or parasites to worry about. No swarms, no neighbor issues, no big hive messes.
However, Mason Bees where I live don't even hatch out of their cocoons until *after* the plums blossom and generally after (or late into) the sweet cherry bloom. For apples the timing is great, hatching in early April and remaining active thru the end of May.
Also, when your Mason Bees hatch out, if there isn't sufficient flower forage in the area, Mason Bees have no choice but to abandon the area.
I doubt I need the Mason Bees but they are a fun activity. When my plums are blooming and there aren't any bees around, when I walk up to those trees I can see various insect activity throughout. Flies and gnats and such... I guess.

Where do I find a few Mason bees in Toronto Canada

"kokos"
In a word you don't. The only place I have found in Canada is from the West Coast.
Might I suggest a visit to the URL below. No sales involved just information on rearing/keeping Mason bees.

Here is a link that might be useful: Mason Bees

that's no good.....there has to be a source of bees to buy somewhere in ontario

I can get honeybees do they sting and are they aggressive?

Honeybees are much more aggressive than mason bees, and they will sting if they sense that the hive is in danger.

I wouldn't say honeybees are aggressive but they will sting when they perceive a threat to themselves or to the colony. Mason bees would rather abandon their nests than sting. I have read that a mason bee sting is more like a needle poke than a typical bee sting. Keeping honeybees you will have to do regular hive maintenance that requires getting into a hive with thousands upon thousands of bees inside. It's no picnic.

Around here, I've got all sorts of little wild bees and wasps that work hard. They aren't very noticeable. I only see them because I am looking every day.

My suggestion is to plant some assorted flowers with a long extended blooming period. If your yard has flowers from spring to fall, the bees will come to your yard all year and they will be there when the fruit trees bloom.

The bees here like zinnias, sunflowers, marigolds, and cone flowers. All of those are cheap and easy to grow. Only the sunflowers take up space. The rest can be fit in just about anywhere.

I put in the sunflowers for quail food. The tweeties got them; the quail didn't get a single seed. But the bees were working the sunflowers really hard, so I will plant them again.

I just bought 50 Mason Bee cocoons and will store them in my "cool room" till spring. Found as supplier in BC that ships to Ontario.

I'm a little confused where to place the nests, raccoons and cold are the worry.

Koko, if they are individual cocoons, or even in straws, you can just put them in any sort of a box with a convenient escape hole in it. You would place this as close as possible to the nesting tubes that you wish for them to use when they emerge. That is... assuming you will be providing nesting materials. If not then your only concern is to release them in a dry spot near your trees and hope they can find lodging nearby on their own.
A good location is on a house or shed structure, under the eve high enough that rain doesn't get to them. An east or south exposure is best to warm them up on cold mornings so they can get busy. Never put them on a northern exposure.

I concur with tcstoehr.

Put the box with your straws and have the hole in the box facing towards the back of the shelter. Mason bees will leave the box, crawl out of the straws, and memorize their area. You might catch them "dance" in the air zig zagging back and forth.

Place your shelter about head height or above. You want to enjoy watching them, but don't want a stretching racoon to get in. Cold shouldn't be an issue.

With plum blooms, you can either pre-emerge mason bees (our website in commercial section gives suggestions),OR, just paint the blossoms with a paint brush or "ov-gloves". I tend to do this at my house and have 1,000 + mason bees.

Here is a link that might be useful: Crown Bees