Matt, if you want a guaranteed way to grow a peach in zone 4 make a cover out of aluminum bubble wrap insulation. You can buy this stuff by the roll and use a regular stapler to "sew" together a large cover for your tree. You use ground staples to attach the edges to the ground. It will be about 20 degrees warmer under the cover since the heat of the ground will come up. I used this idea on my figs and had a thermometer under the cover to confirm the temperature difference. You should be able to grow any moderately hardy peach this way. I don't need the cover for peaches since they are hardy for me, but I used it on figs and pomegranates and it always worked well. The main problem is the wind, the cover needs to be secured very well or it will blow away. Ropes over and around it once it is on helps secure it.

Scott

PS here is a picture of one of my fig covers; its about 6' tall:

{{gwi:60489}}

Scott

It's more tricky than that up here. When it's minus 30 with a wind chill of minus 45 I'd need a heater inside of that . I think the idea is correct except I just need to keep the tree frozen always by just covering it from the sun so it stays cool always.

I think once the tree is hardend off I just need to keep it that way. If I used something like the silver bubble wrap it would wake the tree during the day and night it would drop to minus 25 . To drastic . It would work if I put a heat source for night time.

But again these nurserys are claiming zone 4 hardy? I could cover the trees for the winter and remove the covers late spring which would be full proof if infact these trees are zone 4

I'm right on the tip of zone 4

AH I remember you asking this a week or so ago matt...

One thing I will mention. Im assuming you are in Calgary or lethbridge. Please be careful with the zone ratings there. Calgary is rated zone 3/4, and I was there when it was -43C before the windchill (thermometer and the weather channel both confirmed this). That will definitely kill your peach tree, or most fruit trees for that matter.

The same goes with peach trees hardiness. They seem to be hardy to southern zone 5, which is slightly different then our zone 5. The duration of the cold down south is nothing compared to alberta, where I have seen at least 3 weeks of -30C consecutively.

Ive been researching this same question for a while now (im in zone 4, near a lake which moderates the temps). One of the best things you can do, is keep the tree cold there. The chinooks followed by the falling temps will cause the trunk to split. Again, I remember weeks where the temp went from -20C to 15C in 2 hours. IF you keep the sun off of it, you help keep the trunk cool, and have a less chance of this happening. From what ive read, that can make or break your chances of growing a peach.

I will say this though, Im not trying to discourage you, or say its impossible, just saying its going to be tough. Then again, that makes the end result more rewarding right :D

THis might help. ITs the ontario government site for agriculture, and it lists some of the species grown. S ontario is pretty much the furthest north peaches are grown here (of course, besides BC)

http://www.omafra.gov.on.ca/english/crops/facts/07-041.htm

I bought several peaches that I thought were not hardy enough for my zone. I used Scott's technique of using reflective bubble wrap but what I did was make a circular fence with wire re-mesh and filled it with leaves and covered that with silver bubble wrap insulation. I didn't cover the top, but if I had I would have made it cone-shaped. This worked well for me, but if I did it again I would wrap the trunk with hardware cloth so mice couldn't girdle it.

It turns out that O'Henry and Silver Logan have done fine in zone 5 and I don't do this now. I'm going to try it on my Chicago Hardy figs this year, thanks to Scott!

I am in zone 4a and have tried Contender, Reliance, and PF-25C. They all winter killed. For what I spent on the trees I could have bought a lot of peaches, so it's three strikes and they are out. There are many elaborate experiments people have tried with lights, coverings, pots in garages, etc., but if you decide to travel away from home for a while in the winter or have an unexpected health problem, those things aren't always practical to keep up year after year, so it is better to grow things that can make it through the winter unaided, except for rodent and deer protection or paint for sunscald protection. Northwoodswis

Matt,
It sounds like you have a great system going for your genetic dwarf potted trees... they should be what you rely on for fruit. You might be able to get some peach tree to survive in the ground, but not without a lot of ingenuity, work, trial and error, and winter kill.

Where I live we had some freak zone 4 cold (-20's F) a couple winters back, but it was just a single night, and some established peach trees were still killed outright while all experienced die back to varying degrees.

So to make a long story short, I do not believe in a true zone 4 peach... if I lived there I would do the cover thing, the pot thing, and grow lots of apricots instead (they're much hardier, more expensive in the market, and even better home grown than peaches).

Here's an article about someone trying to grow peaches in North Dakota:

Here is a link that might be useful: http://www.inforum.com/event/article/id/373760/publisher_ID/1/

Apricots are my favorite fruit I have 4 trees already lol
I just see these claims of zone 4 hardy . Ive been talking to the nursery making these claims they say the trees must be grown as shrubs so snow will cover them all winter. I'd emagine alot of fungal bacterial issues being under frozen slushy water and snow. Also I love the true beauty of how a peach tree looks. It's by far the nicest looking prunus tree. I won't consider growing a peach shrub it's not even an option to me.

Apricots are my favorite fruit I have 4 trees already lol
I just see these claims of zone 4 hardy . Ive been talking to the nursery making these claims they say the trees must be grown as shrubs so snow will cover them all winter. I'd emagine alot of fungal bacterial issues being under frozen slushy water and snow. Also I love the true beauty of how a peach tree looks. It's by far the nicest looking prunus tree. I won't consider growing a peach shrub it's not even an option to me.

I know someone who grew an apricot from seed in Calgary. It survived some cold winters while I was there. Last I heard it set fruit for a year or 2 before she moved.

Again, here is the ontario agriculture list o culivars they use. Maybe a good start?

http://www.omafra.gov.on.ca/english/crops/facts/02-035.htm

Apricots are hardy trees. I know of a few in Alberta. The trees are really rare to find here and theirs some real good cold hardy zone2/3 hardy varieties .