I would like to grow an Acer shirasawanum 'Jordan' here in Ottawa. Unfortunately, the climate is too harsh for the tree to survive in the garden. Does anyone know if it is possible to grow this specimen in a container? If yes, how large should the container be, and what restrictions are there to over-wintering in a garage? Some advice would be greatly appreciated.
Plant in a tub, expect to be repotting periodically. Overwinter in cool and humid environment, cooler than inside a house but not freezing severely. Enough moisture to prevent drying out but not enough to produce a mold problem. Be sure to monitor moisture content of potting medium even when dormant.
Thanks Ron - good to know that it is possible. Our garage is just above freezing during warmer winter days and just below freezing when it is -30C outside. Since it is not particularly humid, I would definitely have to water it to keep it at the correct moisture level. Now I will have to try an get one shipped to Ottawa in the early spring :-)
What is the climate like there in Ottawa iway? I've never tested it but A. shirasawanums are though by many to be a solid z5 plant.
Our friend Zonebreaker who lives in Northern Sweden (zone 4) grows successfully in the ground A. shirasawanum 'Aureum' http://www.botanicalgarden.ubc.ca/forums/showthread.php?t=47851&highlight=zonebreaker Gomero
Shirasawanums live and grow in my zone 3-4 in sweden,give them a try you will not regret it! Plant in well drained sand and in a elevated bed. God luck!
About the same conditions i have for some of my palmatums except my earth basment is humid. Be carful and not over water it during dormency,havent watered any one of my potted acers yet, almost 5 month now.....
What would you say is the purpose of watering, since the tree would be dormant, including the roots, I assume? And how would you gage the correct moisture? Do you use a moisture meter that gages the root-level moisture? Ingrid
In a garage the air is much dryer than in a earth basment so the winter air can dry the soil out during a long winter. sorry for the intrusion of the thread.
Good point. I suppose I could alway create a plastic 'tent' over the soil to retain moisture. Thanks for the advice.
Acer shirasawanum is generally believed to be more hardy than Acer palmatum. There is another member of this forum (bamboofish) who lives in Ottawa area, and grows and supplies many varieties of acer palmatum for various nurseries around here. You should have a good chance of success growing it outdoor, but selecting a location protected from winter wind and sun helps a lot.
Fully agree, their native range in Japan confirms. Disagree, this cultivar (as opposed to 'Aureum') requires full sun to keep the yellow coloring of leaves. And I bet that Ottawa's sun is probably milder than in Southern France. Gomero
maf That is exactly what I meant. In particular, the chance of winter damage appears to be inflicted under a combination of low temperature+wind+strong sun. Many maples and even conifers 'appears' to be a lot 'hardier' when such condition is avoided. Ottawa is in Zone 5a and I am in Zone 5b.
Sounds like I could plant it directly in the garden in a protected area. Our temps get to -30 C as well, although we have not had any that cold this winter. I would wrap with burlap to prevent wind damage. Thanks again.
I have a hard time figuring out how the winter sun at those latitudes could be detrimental to trees. The only effect that I know (and have experienced) is that the lack of direct winter sun leads to poor colouring for the red-bark maples. Gomero
Gomero, my understanding of the situation is that cambium damage can occur when the bark cycles between being warmed up by the sun during the day, and severely frozen to very low temperatures at night. The problem is worse with young Japanese maples with thinner bark, and in late winter when the sun is stronger. It has been suggested that the level of dormancy needed for the cambium to survive the very cold temperatures is interrupted by the warming effects of the sun. Ottowa is far to the south of where I live, I imagine the sun can be quite strong there in late february. Thankfully, you or I are not in a marginal hardiness zone for Acer palmatum so do not have to face this situation. Maybe someone with personal experience can confirm/deny/flesh out the above.
Here in the middle of the US where we get plenty of sun and very cold temperatures (-21F, -29C on January 8 this year, coldest since 1886) I've seen winter sunscald on lots of trees. It can definitely hurt japanese maples, as well as many other trees with thicker bark. Last year my parents had to remove a large English oak (Quercus robur) from their yard after it eventually succumbed to severe sunscald it received when it was a juvenile. It had a large scar running about 2m up from its base - the only tree with the scar, the oaks nearby are still doing fine. Maf hit the cause on the head - it's due to fluctuations of winter temperatures. Around here almost all sunscald (and "frost cracks" as described in article below) occur on the southwest facing side of the trunk - the side that gets the warmest sun just before nighttime temperatures return. This article from a Farm Production Extension Pathologist in Canada talks a bit about it: Winter Sunscald and Frost Cracking: Tree Bark Damaged from Winter Bite PS - I'm also looking forward to planting a 'Jordan' this year! It might have to replace one that didn't make it through this extra harsh winter.
That is an interesting article and has made me aware of damage to some 10 year old maples at the edge of our property. I shall be more cognizant of such damage in the future. Thanks and good luck with your planting.
Thanks Maf and prairiestyle, I have learned something I did not know. I am glad I do not have that problem. I wonder, for example for Sango kaku et al., how to manage the need for sun to redden and the protection from sun to avoid damage as explained, do gardeners in those zones have removable protection? Gomero
From my experience, it seems like the trees usually affected are the ones in the most exposed locations - ie on a hill with full sun. I've planted my japanese maples in locations that are generally protected from strong afternoon summer sun, and this carries over well for winter protection too. Plus, I am near the bottom of a valley that runs North-South so my yard stops receiving direct sun well before sunset. I have seen many young trees wrapped (along with those that have forgotten to be unwrapped the following spring) but it's not something I do myself. As for coral barks, I'd imagine it would depend on location and the planting conditions, though in the right spot there'd be plenty of sun to induce good color while also being protected. But to memory I don't think I've ever seen a mature tree planted around here. I don't personally have any as I've shied away from cultivars with any reputed tenderness issues (as well as early-leafers) - as our weather is sometimes quite demanding!
Just a quick update on the thread started 3 years ago. I received and successfully overwintered my "Jordan" in its pot. Last November I moved to a new location and planted the Jordan in my new garden. It has never been more beautiful, and is loving the full sun.
Update please, after this long and very cold winter. How is your Jordan doing this spring? Thanks, Kevin in KC
