Most trees and shrubs produce roots near the surface, where the air is. Mulching with wood chips could improve results, a sprinkle of dead leaves over a narrow area near the bottom of the tree is not much protection. A sheltered position could also improve results, magnolias are woodland trees. A similar small 'Edith Bogue' here had the branches peel off under slushy snow. Plants sold as 'Victoria' that do not have good indumentum may not be the true item. What I consider to be 'Victoria' produces somewhat ovate leaves with conspicuous pinkish sheaths over the newest ones at the ends of the shoots - reminiscent of those displayed by Ficus elastica.

I have grown Magnolia grandiflora "Edith Bogue" successfully in Guelph Ontario for 3 years. Planted outdoors in moist clay loam , slightly above grade and acidified by pine bark, peat moss, humus mix as top dressing . Watered regularly in winter thaws with luke warm water to keep surface roots drawing moisture for leaves ( to mitigate wind desiccation/ winter sunburn ) Flowered 3rd year after planting. Now 9ft high ( 8-12 inches /year) . Growing well this spring (2014) after extraordinarily cold winter down to negative 34C for several nights in January/February. Some leaf dessication this year (first time since planted, probably because of very cold winter)) and 25% leaf burn from spring sun (possibly due to late soil thaw this year as sun got stronger), but these leaves will drop anyway as a matter of course to be replaced by new leaves by June 1. New leaf buds already swelling. Also successfully growing Magnolia asheii, Magnolia virginiana "Porcelain Dove ( amazing plant), 2 hardy crape myrtles, 5 hardy camellias, stewartia and franklinia alamataha amongst other rare/ endangered / and zone pushers. All doing well.

It depends what you mean by "grown successfully in MN". Do you mean a "charlie brown x-mas tree" type thing that barely survives with lots of protection or a 50 foot glorious tree with luxurious green leaves blowing in the arctic January breezes in MN? I used to live in Mpls so I am familiar with winter there. I now live in a marginal zone 7a in coastal SE Mass where I do grow southern magnolias. In my experience, there are two varieties that grow reasonably well here.....Edith Bogue and Bracken Brown Beauty. By "reasonably well" I mean they grow into small or medium sized trees 20-30 ft tall. And they bloom in early summer. The Edith Bogue is hardier and experienced no leaf damage here this winter. It is considered the hardiest southern magnolia. The Bracken Brown Beauty is less hardy and experienced about 50% burn this year here--growing in full winter sun I might add--but the branches and buds are all alive. Just for a point of reference, my location had only ONE below zero morning this winter (-7) and we average one such morning every 3 years--hence the marginal zone 7a designation. So I think if you wanted to try growing one you could try an Edith Bogue. But....it must be small enough so that you can protect it--a lot. Zone designations are misleading because they don't include duration of cold or wind. Even a "mild" Mpls winter features many below zero mornings--and many more windy mornings with just above zero readings. And then there is that occasional day where the temp might stay below zero all day. That kind of constant assault of cold and wind probably kill even the hardiest southern Mag without protection. So build an enclosure for it. Fill it with leaves and pine needles. Then wrap it in burlap a few layers deep and hope for the best! There used to be a forum member in Mpls who I communicated with a few times many years ago. He planted a variety called "24 below" but I lost touch and I have not heard anything about that variety since. Good luck!

Congratulations njoasis! Although I do support my local garden centers, I also love a bargain and I don't hesitate to go to a big box store. The Lowe's near me in Lawnside is always putting plants on sale because they haven't been cared for properly. Last year I bought a large leaved rhododendron for $1 that's doing beautifully. Enjoy your magnolias. Leslie