Hardiness of Metrosideros umbellata

Discussion in 'Outdoor Tropicals' started by Deneb1978, Aug 24, 2009.

  1. Deneb1978

    Deneb1978 Active Member 10 Years

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    Hey,

    I am wondering what is the hardiness of Metrosideros Umbellata is. I read that this tree has been grown as far north as Scotland in the Northern Hemisphere. I wonder if anyone has ever tried this tree in the Pacific Northwest anywhere and if it could succeed.....
     
  2. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    The ones in Scotland (Logan, Inverewe) are in zone 9. It is slow-growing there (Logal tree is just 6m) and hasn't been successful in any colder areas of Britain.

    One on the south coast of Ireland (just into zone 10) is 14m tall.
     
  3. Ron B

    Ron B Paragon of Plants 10 Years

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    Yes: western coastal Britain is warmed by the Gulf Stream, taking some of the significance out of statements like

    "As the hardiest Metrosideros it has been planted and succeeded as far north as Scotland"

    http://en.wikipedia.org/wiki/Metrosideros_umbellata

    Lots of stuff grown quite far north there is hardy only to southernmost coastal Oregon here.
     
  4. Deneb1978

    Deneb1978 Active Member 10 Years

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    Yes that's true.... that is why when it said it was grown as far north as Scotland, it seemed ambiguous to me as well. It depends where in Scotland it is grown of course.... too bad that it can't be grown here. It looks like quite a beautiful tree.
     
  5. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    The one at Inverewe is at 57°45'N. In latitude, that's midway between Sitka and Juneau in Alaska.

    I'd suspect it would also be worth trying in the Faroe Islands (62°N); I've not seen any mention of it being tried there, but several other species from the same parts of New Zealand are doing well there
     
  6. Deneb1978

    Deneb1978 Active Member 10 Years

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    Interesting... I've never been there but I wonder if the climate of our Queen Charlotte Islands (53 degrees north) could be compared to those of the Faroe Islands even though it's much further south. The islands lie much further from the coast than Vancouver Island does (the Hecate strait is up to 140 kilometres wide at its southern part) and so probably wouldn't be subjected to as many arctic blasts. In fact during the last ice age, the islands almost completely escaped glaciation I read.... who knows.. some sheltered place on the west coast of these islands in the right spot could be quite mild and could support some of the same plants as at Inverewe like Metrosideros....
     
  7. Ron B

    Ron B Paragon of Plants 10 Years

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  8. Deneb1978

    Deneb1978 Active Member 10 Years

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    True the warming effect is not nearly as great as the Gulf Stream but it's still warm enough to keep the islands quite mild. "The moderating influence of the Pacific Ocean ensures that there are no extremes of temperature, summer or winter. Average annual temperature is 8 degrees Celsius (46 degrees F)." Nowhere in that article does it say anything about arctic blasts and while I'm sure the islands receive them, they are probably not nearly as severe as other places in the region. Most other places in the region are much closer to or on the mainland and thus would not have nearly the protection. Water is a great insulator and any cold arctic air would have more water to cross which would warm it up....and considering it's almost 10 degrees further south than the Faroe Islands (62N), the water temperatures around the islands would be roughly the same between the two places when you take the warming effect of the Gulf Stream into account.
     
  9. Ron B

    Ron B Paragon of Plants 10 Years

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    The Gulf stream cancels out the latitude to a large extent. That is why western coastal UK is much milder than many other places at the same latitude. If the Charlottes were as mild the native trees would be coast redwoods instead of Sitka spruce. In California the spruce is replaced by the redwood because of the different climate.
     
  10. Deneb1978

    Deneb1978 Active Member 10 Years

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    True but Coast Redwoods I am sure can grow in the Charlottes. In fact the Wikipedia article on the Coast Redwood says that they are grown there...Coast Redwoods have a very limited natural range anyways due to a number of factors not just cold hardiness.
     
  11. Ron B

    Ron B Paragon of Plants 10 Years

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    Plants grow wild where they can live over the long term. In 1990 towering planted coast redwoods in western WA had their foliage burnt by the cold.
     
  12. Deneb1978

    Deneb1978 Active Member 10 Years

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    Western WA (and the rest of the BC mainland coast) is not nearly as protected as somewhere like the southern part of the Queen Charlottes would be from arctic blasts as there is no large body of water between it and the source of the arctic air to modify it. Same thing happens in Europe... somewhere like Paris or Amsterdam have a lower hardiness zone rating than somewhere like Dublin or Belfast because there is a large body of water between it and the source of the arctic air to modify it. Therefore they should be able to support hardier plants.
     
  13. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    Coast Redwood is most likely not native to the QCI because of its more limited seed dispersal abilities compared to Pinaceae conifers which have much lower seedwing loading (wing area divided by seed weight). A Coast Redwood seed is about the same weight as a Sitka Spruce seed, but only has about a quarter of the wing area.

    Another advantage that the QCI have over Vancouver (city) is that there is no major river valley facing them to channel arctic air outflows in their direction. Vancouver suffers when cold pours down the Fraser Valley. I'd say Metrosideros umbellata would be well worth trying on the QCI, somewhere like Jedway. Places like Tofino and Kyuquot on the west coast of Vancouver Island might also be worth trying.
     
  14. jmlord

    jmlord Member

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    HI - in the southern hemisphere Metrosideros umbellata (southern rata) grows as far south as 50.75deg but in coastal areas, and although it grows in mountain environments here in NZ its maximum frost resistance is less than -10 celcius.
     
  15. Ron B

    Ron B Paragon of Plants 10 Years

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    Grimshaw/Bayton, New Trees - Recent Introductions to Cultivation (2009, IDS/Kew) rate it Zone 9, say that although the hardiest species it still needs it quite mild. They do suggest attempting increased cultivaton along the southern coast of England - in presumably suitable planting sites only.
     
  16. Deneb1978

    Deneb1978 Active Member 10 Years

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    The outer shores of Vancouver Island and Western Washington are borderline hardiness zone 8b/9a I would say and sunset zone 5 (minimum temps over a 10 year period -8C to -15C). Metrosideros Umbellata might need some protection occasionally from cold temps in this area (say 1 out of every 10 winters) but overall, should do fine otherwise.
     
  17. Ron B

    Ron B Paragon of Plants 10 Years

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    The USDA 9 equivalent on the US coast starts about Coos Bay, Oregon at best. That is where the apparent USDA 9 indicator Cordyline australis is first able to grow for indefinite periods without having its tops freeze down to the crown.

    Sunset 5 corresponds to USDA 8. If we determine that USDA 9 actually corresponds to Sunset 17, then USDA 9 does not start until Gold Beach. If the Sunset climate zone map for western WA and the 1990 USDA hardiness zones for the same area are compared Sunset 4 and 5 line up with USDA 8.
     
  18. Michael F

    Michael F Paragon of Plants Forums Moderator 10 Years

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    How well has this been tested, though? Very few people living on the west coast of Vancouver Island, and even fewer of them experimenting with Cordyline, Metrosideros, or other exotics. I'd be surprised if they didn't succeed there.
     
  19. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    There are Cordyline plants growing in Tofino / Ucluelet that are at least 20 years old.

    Read this thread on Cloudforest for a discussion on the hardiness zone of the area.
     
  20. Ron B

    Ron B Paragon of Plants 10 Years

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    Yes, claims of Californian conditions for Vancouver Island have been made on internet forums for years.
     
  21. Daniel Mosquin

    Daniel Mosquin Paragon of Plants UBC Botanical Garden Forums Administrator Forums Moderator 10 Years

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    Heh, yes -- I just looked at the data. Lowest temperatures in each of Nov, Dec, Jan recorded in Tofino:

    Jan. 30, 1969: -15C
    Nov. 29, 1985: -12.7C
    Dec. 28. 1968: -12.2C

    So, that would put Tofino at a zone 7. However, the historic low in Tallahassee, Florida is -2F = -19C (putting it at a 6b), but Arbor Day Fdn records it as zone 8. So, with the zone systems, there seem to be some exceptions made?
     
  22. Deneb1978

    Deneb1978 Active Member 10 Years

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    I think the USDA zone system is based on the average minimum temperatures over a set period of time... . That -15C in 1969 was an aberration I think... I highly doubt that Tofino has been colder than -10C in the past 20 years. Even last years deep freeze, I don't think it got down to -10 in Tofino. That would probably at the very least place Tofino in USDA hardiness zone 8b and possibly even in 9a in some sheltered microclimates. But as everyone knows, the USDA hardiness zone is not very indicative of whether a plant can survive at a given location or not....
     
  23. Ron B

    Ron B Paragon of Plants 10 Years

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    USDA Hardiness Zones based on something like 15 years. Average annual minimums are used to lay them out. The system started back east, where it is possible to stretch large bands over the mostly gentle landscape and get something that corresponds to the actual situation - unlike out here, in the mountainous West, where the same style has sometimes resulted in different climates having hardiness zones stretched over them in a highly artificial and inaccurate way.

    When you are trying to grow trees and shrubs that you want to last for more than 10, 20 or 30 years those occasional killer drops are exactly what matters. If, on the other hand the excitement of having something that "doesn't grow here" last temporarily is adequate compensation, then the fact that it is likely to be lost at some point may not be a problem.

    Unfortunately, you don't know what year that next big freeze will happen. Rare specimens can cost hundreds of dollars to locate and acquire. In milder climates like ours there are lots of interesting kinds of plants that can be grown that are not so likely to be lost later to a sharp winter.
     
  24. Deneb1978

    Deneb1978 Active Member 10 Years

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    I think with gardening, there are always risks. Sure, you don't know when the next big freeze is going to come but that doesn't mean that you should not try and experiment a little. To give you a good example, look at the citrus industry in Florida and California. Every 10-15 years or so, they get a devastating freeze that wipes out millions of dollars of fruit. When that happens, do they just give up and say oh well it can happen once, and so it will happen again and so we shouldn't bother even planting citrus here anymore?.....No, they keep trying and do the best efforts they can. If they had never taken these risks, we wouldn't be able to enjoy all the fruits of their labour (fresh oranges, lemons, grapefruits as well as the juices). So, people should take risks because that is what life is all about.
     
  25. Ron B

    Ron B Paragon of Plants 10 Years

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    I think I heard or saw recently that the citrus industry in that region is now in fact packing it in. But I have no specific information.
     

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