How hardy is C. Kousa anyway????

Discussion in 'Cornus (dogwoods)' started by bamboofish, Jan 29, 2008.

  1. bamboofish

    bamboofish Active Member

    Messages:
    33
    Likes Received:
    1
    Location:
    Ottawa, Ontario,Canada
    Hi,
    I'd like to here from anyone in the north, who blooms cornus Kousa, as to which ones are the hardiest.
    They are said to be hardy to zone 5. We are zone 5 here in Ottawa, but nobody grows them. I have a couple that grow but never bloom or bloom very little. Kousa is said to be hardier than C. florida. I have it as well but no blooms. i have an acid soil, good mulch, light shade. I never have winter kill. they are 4-5 footers and established for 3-5 years.
    Anybody got any ideas??

    Rich
     
  2. Ron B

    Ron B Paragon of Plants 10 Years

    Messages:
    20,991
    Likes Received:
    679
    Location:
    WA USA (Z8)
    "Hardiest and strongest grower of all the dogwood species we have in production. Exceptional vigor.

    No visible dieback or winter burn during our most severe winter blizzards and subzero temperatures of the past 25 years."

    http://www.lakecountynursery.com/galilean.htm

    "Cornus kousa is cold hardy to USDA zone 5, although it has potential for solid zone 4 with some new introductions likely to come onto the market over the coming years. In 1984, a U.S. expedition including Paul Meyer of the Morris Arboretum, Daryl Apps, Peter Bristol of the Holden Arboretum, and several others collected seed in South Korea. This Korean collection has yielded plants with excellent cold hardiness. John Wachter, who was working with Paul at the Berheim Arboretum, Clermont, Kentucky, at the time, tested several accessions in their lab and found more than one plant able to withstand -30F (-34C) or better. Stay tuned."

    --Cappiello/Shadow, Dogwoods (2005, Timber Press)

    If your plants were raised from seed they may not be old enough to bloom yet.
     
  3. smivies

    smivies Active Member

    Messages:
    793
    Likes Received:
    0
    Location:
    Kingston, Ontario, Canada
    They grow & flower ok in Kingston. Very few around but those that are seem to do well.
     
  4. bamboofish

    bamboofish Active Member

    Messages:
    33
    Likes Received:
    1
    Location:
    Ottawa, Ontario,Canada
    Hi again,
    are you the guy I spoke to before with the bamboos in kingston??

    Richard
     
  5. prairiestyle

    prairiestyle Active Member Maple Society 10 Years

    Messages:
    107
    Likes Received:
    1
    Location:
    Omaha, NE, USA
    I'm in Omaha, Nebraska, which is also zone 5 and I've got a Cornus kousa 'Gold Star' that hasn't had any problems growing in the three years since I planted it. It has yet to flower, but it was just a wee little guy when I got it so I'm going to give it some time.

    There is a species kousa at the botanical gardens here that has had some spectacular blooms in years past.
     
    Last edited: Jul 10, 2008

Share This Page