I don't have any magnolias myself, but theres a star magnolia tree I drive by every spring. It's located on state-owned land next to a roadway. Been there at least three years, from a distance seems quite healthy. It is in zone 6, central Long Island NY. Apparently never tended. Except the grass is mown semi-regularly.

I am north of you in zone 5 and have had one for almost 30 years. It started out as a 1 or 2 foot plant and is just magnificent now. If you go to the garden section of my link below you can see it ..that pic was taken a few years ago.
I think it should be fine in your area. Kareen

Here is a link that might be useful: Our pond and gardens

I'm in lower Orange County. But, up in the mountains. I'm about ten degress cooler and about two weeks behind the blooming of NYC.
My five foot high, two years in my ground, magnolia, has its first white flower this spring!
My four year(in my ground) old apple trees have their first flowers now as well! Perhaps this will be my first year of fruit!!!
I keep telling my wife that by the time we are one hundred and fifty years old...we're going to have a beautifull garden...

I am very interested in this same question, as I have a weekend place in Delaware Co. and am also considered Z4, and LOVE the magnolia here in Brooklyn so much! Wayside Gardens has at leat two magnolias they say are hardy to Z4...on the other hand, I don't see anyone up here with magnolias, which leads me to wonder...

However, my experience in watching two magnolias within a couple hundred feet of each other in my Bklyn backyard has also convinced me of the importance of looking at microclimates when planting delicate creatures like magnolias; each year (I have observed this for at least the past 6 years), there is a full 10-day to 2-week difference in the blooming of these two otherwise identical trees. So maybe the trick is placement...finding a little patch of Z5 on your otherwise Z4 terrain. Just a thought, for what it's worth. Good luck!

I have a very hardy hybrid magnolia and it has done fine with temperatures down to 20 below 0. It's almost finished blooming now but it was a sight last week. The only problem I have is that it is growing taller than expected and has to be cut back so as not to interfere with the telephone wires. I think its name is Merrill. It's a hybrid of the star magnolia but is much bigger and much hardier.

Catskillcottage, I'm interested in knowing if you went ahead w/ the 'Butterfly' planting. I am in the mood for a magnolia and thought Butterfly was a beauty. What happened?

I'm in the Binghamton area. I planted a magnolia 10 years ago. It started out as not much more than a twig and for several years seemed to grow rather slowly. This year it's just taken off.
Mine is in a somewhat sheltered area near the house.
My mother who use to live in the area also planted one a good 30 years ago it too grew very slowly...hers was a different type...less leafy than mine.
The scent from the flowers in the spring is truly worth the wait!

I am in FL and have a gorgeous magnolia that is over 30 years old. They must be deep root fed - we put 3 foot tubes about 10 ft from the tree, all the way around, and fill with either 6-6-6 or gardenia food (better). You will have plenty of flowers.

I'm not at all sure why fertilizing magnolias is necessary....unless one is working with rather alkaline soil conditions (magnolias prefer an acidic soil). Generally, trees established in the landscape require little, if any, fertilizing unless if growing in less than favorable soil conditions. Magnolias will bloom freely without any additional attention as long as spring frosts don't damage the early budding types. Which is a distinct possibility in upstate NY.