I find this interesting as, having grown a banana plant on the deck last summer, I have been doing research on winter storage methods. Have you read the book "Hot plants for cool climates" which covers the subject of tropical gardening, winter protection methods, etc?

Apparently one way to over winter certain bananas is to dig up and store the root in a cool dark place, similar to storing other bulbs. Unfortunately I don't have such a place so I am trying to keep my banana alive as a houseplant in a bright window and watering sparingly. For those who are wondering, the main advantage to keeping a plant alive as opposed to starting another from seed is that next year it will grow bigger and taller, more impressive.

Apparently other winter protection methods for bananas involve keeping the plant outside in the ground and mulching heavily with bags of leaves to keep the roots and base of the stem from freezing. While I know this method has worked for some in zone 6 I have my doubts it would work in zone 3 Winnipeg as we get too cold for too long and eventually the soil underneath would freeze.

One nursery website, link attached, stated the windmill palm as the hardiest and zone 3 hardy. I love the website, fun pictures. I am not sure a palm would survive zone 3 Winnipeg, however, as like I said it's just too cold for too long with weeks of below freezing temperatures. It's nice to dream and devise ways to make things work, however.

My latest project is to try and fill my yard with cold hardy plants that look tropical, mixed with real tropicals. Catalpa, hardy yucca, petasites, etc. Then on my deck last summer I had a (non-hardy) majesty palm and a hibiscus. It's definitely a fun idea.

Not really a tropical plant, but I do know that winter protection can make a difference. I have a ginkgo biloba that survives here but suffers winter damage. I therefore surround it with a frame of 2x4's and staple some plastic tarp material onto that. Protected out of the wind all winter, it seems to come through very well (at least in past years, fingers crossed for this nasty winter). So, if anyone can figure out a way to grow a palm on the Cdn prairies and have it survive, I probably would be one person willing to go through the extra trouble, just for the fun of it.

Glen

Here is a link that might be useful: ty ty nursery

Glen, do you have a catalpa tree? Someone sent me seeds a few years ago and i have one that has grown and was planted in the ground this summer. I mulched the roots with leaves, and it's still only a foot or so high, so i'm hoping the snow will help insulate as well. It would be interesting to see how big it would grow here.

Great thread, I love out-of-zone plantings!

Can a windmill palm really be grown in zone 3 or 4, even with generous winter protection? That would be great, but is seems way out of zone here in the Cdn prairies. I checked out the website, and I've seen them growing on the west coast of Canada (pic included below), but that's a very mild climate, like zone 8 or thereabouts.

Catalpa seem reasonably hardy for prairie gardeners looking to test the limits. I've got a small one (two feet high and several years old) growing in my increasingly shady back garden here in Edmonton. It's still very small and is sheltered from winter winds by a nearby fence, but it doesn't seem to have suffered much winterkill during the past couple of winters (but they weren't harsh winters).

Ginkos are great... I had a small one but it didn't make it past it's first year in Edmonton's suburbs, yet I know of one on the University grounds downtown that has survived at least 10 years. Actually, I haven't seen that tree in about 10 years, so I really need to locate it again and see if it is still doing okay. I used to also watch a ginko growing in Drumheller, Alberta, near the Red Deer River (pic included below) -- last I saw it was small but healthy, but I haven't checked it out for the past decade so I really need to take another look.

My sugar maple is about 12 feet high, growing more as a bush than a tree. It is maybe 10-12 years old, and has a fairly thick trunk. It can winterkill quite severely, but has been doing pretty well the past 5 years or more.

I have a butternut tree roughly 12-15 feet tall, at least 10 years old, and it has produced nuts for the past several years. My grapes (Valiant) produced heavily this fall, and the wine from them is now bottled. Pears (Ure) are usually ignored when they ripen, but they are tasty and the tree has been growing vigorously for 15 years.

Magnolia and Northern lights azalea survived several winters but seemed to get increasingly smaller each year, eventually discarded.

Forsythia did great in a mild winter, but crappy otherwise, and were a pain to chop out, including all the sucker-plants.

Well, that's all my info on out-of-zone plants. If I can actually grow palms here in zone 3, please let me know!

Ginko growing in Drumeller, Alberta - 5 to 6 feet tall, healthy but with some winterkill of top branches
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Windmill palm growing in a garden on the Sunshine Coast, north of Vancouver, British Columbia.
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I have a Chinese Catalpa (catalpa ovata) that has ovate-shaped leaves. ItÂs planted in the ground and about 3 feet high. I also have a catalpa speciosa in a pot (that one has more heart-shaped leaves). The first is apparently a small tree, the second a medium size tree, at least in warmer zones

Some sources state catalpa ovata as hardier. Not sure as both have survived very well for me. The Âovata did bloom in itÂs second year and did develop those long bean-like seed pods.

There are catalpas growing on the Manitoba legislature grounds by the river. Not sure of their age, but they are perhaps 15 feet tall and multi-trunked and look slightly disfigured, perhaps due to winter injury.

My ginkgo is about 7 feet tall. ItÂs sort of an odd tree in itÂs growth habit. For the past two years itÂs gained very little in height, instead adding more growth to the horizontal branch ends. One year it decided to grow itÂs central leader and added 18", but generally very slow growing. Mine has tip kill here and there, but as mentioned I do winter protect. Just so you know, the yellow fall color most nurseries talk about is true, but a bit misleading. Most years the green leaves freeze before changing color, this year was an exception as there was no hard frosts till late October.

Has anyone tried Korean Maple? Mine is more of a shrub than a tree, but around six feet high. ItÂs pretty shade tolerant and itÂs claim to fame is that upon quick glance, itÂs leaves resemble a Japanese-type maple. The only down side is it seems to suffer iron chlorosis (yellowing of leaves due to lack of iron).

Glen

So glad to see your ginko doing that well, Glen. It really is a beautiful tree. Ours bit the dust last spring. DH and I didn't take it out this year, just to make sure, but it will be removed in the spring. It only got to about 4' tall and winter killed so badly that it only had a couple of lower branches on it the year before last. It was a good try but I don't think I'll try another one. We need some quicker trees to get established with our lot only being 4 years old.

Also having a bit of a tough time is our 'Crimson Cloud' hawthorn but I gave it a hard prune in the spring and it put on some good growth this year. I hope it'll really take off next year.

Not sure I'm up to the challenge of trying any palm trees here in Edmonton. I've got quite a wind tunnel that comes through our yard and I think that would do it in, even if I could protect the roots enough. But, I envy anyone that has that kind of success.

Shauna

Arctictropical, I'm going to print off your building plans - not that I think I could actually grow a palm tree up here, though it would be fun to try. I was actually thinking I could probably make your idea serve the same purpose as Sharon's pumphouse. I could make a place that would keep tenders dormant, but just above freezing. Do you have pictures of your palm and banana trees? I bet the neighbors just shake their heads when you uncover those beauties every spring.

Connie

Thanks for your comments Prairierose. It will help seeing the palm boxes. I'll try to dig up some pictures over the weekend and figure out how to post them. I improve upon them each time I build a new one, based on trial and error. I can't see why anyone would not be able to grow a palm in zone 2 if you used this method and caulked the boxes so that they are air-tight. You would just use flourescent lights bulbs with a higher wattage. The reason I use the flourescent bulbs is because they don't burn out as quickly as the incadescent bulbs, something you don't want to happen in the middle of the winter when it is 40 below or in the middle of a blizzard.

This sounds like a very neat idea, look forward to seeing pictures. Do you use the same method for overwintering bananas? I read that with the hardier bananas the top growth can freeze but the roots in the ground shouldn't. Your idea sounds fairly economical to operate and safe too. Do you have a way of checking on the palm trees during winter (that is, possible an opening where you can peek in and see if the lights are still working?) Have you done temperature readings inside the box during winter? Do you mulch the top layer of soil before covering it up for the winter with the box?

I know, questions, questions, but I'm sort of excited about this idea.

As for other ideas, I've sort of wondered what it would be like to build a temporary shed over the garden for the winter. The kind with a metal pole frame and vinyl or tarp material. As it wouldn't be heated you couldn't grow palm trees, but it likely would give you a couple of extra zones of winter protection.

Glen

Artictropical,

I'd like to see pics too! Of the setup and the trees in summer.

How deep does your soil freeze in the open yard? Here the ground freezes two or three feet deep, depending on snowcover. I think that would pose a serious issue of the roots freezing and dying even if the above-ground part of the plant could stay alive here.
-Don

zone 3 needs underground heating cables along with the above ground protection, and even then it might not be enough. 5 feet frost line. that means having to insulate the ground potentially 10 to 15 feet deep just to keep new root growth from freezing year after year as it fills the ground.