Keeping Japanese Maples zone 4

Can't stand it anymore....have to have one! I know it'll have to be in a pot and come into some shelter for winter. Anyone doing this? What would be the ideal temp over winter. We were minus 30 for a bit this winter. That is unusual tho, the last few years. I really want to try..........help, please?

Yes, I'm doing this. Where I live is listed as 4b, but I haven't seen -30 in so many years I now consider myself 5a (wishful thinking?). This year, I haven't seen lower than -10, but there has been wind on those nights so I'm sure the trees thought it was colder.

Anyway, I winter the pots in an unheated garage, and that has worked successfully for two years. As an experiment, I'm also trying some pots in a 50 degree heated garage this year. So far, they have remained dormant, but I do expect they may break out of dormancy too early from the 50 degree garage. If I catch that soon enough, I was thinking I'd then move those plants to the unheated garage to finish the winter. If they seem too far out of dormancy to risk that, I'm planning on moving them to the sunroom until it is safe for them to go outside. The two pots I have in the heated garage are young plants in small pots, that I was worried wouldn't be able to take the cold of the unheated garage. In all cases, I have selected JM's that are listed for zone 5. I would not try this with the zone 6 ones.

It is work, but it is so worth it, I encourage you to try.

Oh, and I forgot to say, there is a Japanese Maples forum on Dave's Garden where you might find more kindred souls.

granitegneiss has the right idea for trying the 50F garage. We need to insulate, insulate, insulate in an unheated garage. One that is attached to the house would probably stay an average of10 degrees F higher than outside. But everytime you open the garage door, you equalized the temp inside and out. Thus the need for insulation, so those sudden exposures to -25 won't devestate.

In the very late fall, put the tree (pot and entire plant) inside a box insulated with styrofoam, newspaper, whatever. The easiest might be to build your own box with sheets of builders "styrofoam" used to wrap the outside of houses or in the attic for insulation. The thicker the better. It will need to be at least one inch thick. Two inches is better and easier to work with. The box will guard against the sudden blasts of frigid air when you open the garage door. Do not water before you the tree in the box. Fairly dry soil is a good thing in the winter.

You do want to use cold hardy cultivars. I have a friend in Bloomington (Minneapolis) who has a JM called Robinson Red. He has grown it outside in the ground for several years with cold damage, and it is at least 4.5ft now. If you can get your hands on that one, it is probably one of the cold hardiest of them all. Try searching for "Robinson Red" here and at GW. I am sure he has written about it in one or both.

That 50* temp info is what I was looking for. Don't have an attached garage and none of the out buildings are heated at all. The veggie room in the basement will have to do. Thanks, Leftwood. Guess I should look more closely, I hadn't noticed the JM forum. Will go there and snoop. And drool!

Actually I hadn't thought about the JM forum, that was granitegneiss. Look up Robinson Red on the Tree and shrub forum too.

I would still try a pot, even in an unheated, unattached outbuilding. Insulate around the base. I pack snow at the top of my pots so on warm days it melts a little and keeps the pot a bit moist. Unlike Leftwood, I would urge you to water the plant as usual until the soil freezes. From what I have read, it is not a good idea to have the roots too dry. Be careful in the spring, that is the trickiest time. You don't want it coming into full sun too soon, as it starts coming out of dormancy, keep it in a protected spot, and move it back into the outbuilding overnight if freezing temperatures threaten after the sap is flowing. From what I understand, JMs are prone to splitting the bark with a cold snap after the sap is flowing. There are many experts on the JM forum who can provide much more insight than I have. But my point is that unheated building in zone 4b should protect the plant enough for it to survive. The cold plus wind chill is avoided, you just get the cold, and you'd be surprised what they can take.

To each their own. If you enclose the entire plant in a box, I stand by my "no extra water" recommendation. If you only insulate the roots, that's a different story.

I'm in Zone 4b and have kept two red maples alive for 4 years now, with one the entire crown froze out so I cut all the dead stuff off mid-summer last year just to see what would happen if I gave it one more year. With the other, the bark split (very nasty) but the hardy little soul soldiered on, and seemed to look pretty good last year. I don't know that I'd do it to trees like this again. They just struggle so. The local landscaper suggested and planted them, so I really didn't know they'd be so marginal in this climate. I also didn't know to wrap the trunk, to avoid the splits that inevitably occur when sun reflect off snow and warms them to a thaw spliting the bark.

I'm in Minneapolis, zone 4a, and I've had an Acer palmatum Robinson's Red (no single quotes since this is a seed-grown selection) in my garden since 2003 and it is outgrowing the space I have for it. I never in a million years thought this tree would survive here, but it is doing almost too well. This tree is in a fairly exposed spot in my yard so it is not protected.

I purchased the Robinson's Red from Girard Nursery in Ohio. Here is a link to the page with the Robinson's Red Japanese maple. It's almost all the way to the bottom of the page.

http://www.girardnurseries.com/Ornamental-and-Shade-Trees-s/47.htm

Good luck,
Mike

treelover3 is my friend I spoke of, and I just realized I made a huge typo in a previous post:
I said:
He has grown it outside in the ground for several years with cold damage
And I meant:
He has grown it outside in the ground for several years without cold damage