I hate to say it, but I would recommend you getting the native Morus Rubra. I don't know anything about Morus Alba or Morus Nigra to help you out, but if you get an itty bitty Morus Rubra, eventually the birds will love you!

Here is a link that might be useful: Forestfarm

You mentioned you're in toronto, where did you find the mulberry trees at? I'm having a hard time finding anything but the umbrella at most nurseries.

Thanks!

You can find a number of different varieties of mulberry trees at Rainforest Nursery. Gardenwebbie, I'm your neighbor across Lake Ontario from you. Since we enjoy eating mulberries so much, I planted both a "Wellington" and an "Illinois Everbearing" a number of years ago and both have done quite well with good-sized fruits. I know Illinois is a alba x rubra cross but I'm not sure about Wellington. I would expect both to be hardy for you. If I recall correctly, Wellington is a variety from the Geneva Research Station (also located here in Western NY State), making it a good bet for our weather.

I've also got a couple of very tiny M. rubra but it will be years before they produce any fruit. I got them from Musser Forests (in Pennsylvania). I love ForestFarm (west-coast) but the east-coast shipping might be a better bet for you plus they would be better hardened to our type of weather.

FataMorgana

Here is a link that might be useful: Raintree Nursery

Morus Rubra have been some of the most successful saplings (18" or smaller) that I've planted in the last year. Most everything else was demolished by the drought or the incompatible soil conditions or whatever. I wouldn't plant $100 trees. I plant $2 trees. The $100 trees suffer transplant shock and won't grow for many years - and may not grow any faster in the long run than the $2 saplings, as cruel as that sounds. You just need to plant more of the $2 saplings because a certain percentage will die in the first couple years.