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wcgypsy

Verticillium Wilt...sigh....

wcgypsy
8 years ago

This is a new property for me....been here 2 1/2 years now and this Spring I've had some losses with plants in one front corner of the yard. First planted were two physocarpus / Nine Bark 'Coppertina' and a Vine Maple / acer circinatum. The two pyhsocarpus at the back of the bed to block neighbor's cars. One physocarpus did not make it....hmmmm. Still wanted something there to grow and block their cars and I had two small dodoneas, so put them there with the physocarpus. In about the middle of this bed, in front of the Vine maple and rather alongside, were three coleonemas and to the front of these were a couple of digiplexis and a couple of echium plantaginums. This Spring the echiums died, the digiplexis died, the two dodoneas died, one coleonema died and a second is on its way out. Since we had a much colder, wetter Winter, I thought that was the problem.....WRONG....my neighbor mentioned two days ago that her big, vigorous coleonema in front of her house, in the foundation border, was dying. I hadn't noticed, came back and took a look at my coleonemas and see the second one dying as well....Looks like Verticillium Wilt......

I don't seem to find a comprehensive list online of resistant or susceptible plants, but from the large variety of plants that have been and are being planted here, I'll probably be able to make a list much better than found online....sigh....

Comments (15)

  • wcgypsy
    Original Author
    8 years ago

    Also hit with the Wilt.......one prostanthera cuneata gone, one dying, one left. I have a large prostanthera ovalifolia in a tub and it is NOT going into the ground. A week ago that was what I had in mind...

  • hoovb zone 9 sunset 23
    8 years ago

    There's a list of vulnerable and resistant genus on Wikipedia, did you see that?

  • wcgypsy
    Original Author
    8 years ago

    Thanks, I did see it, but did not 'open' on it...checked a couple of ag depts, etc. and saw mostly tree lists and commercial vegetable growers...I'll take a look at the wikipedia info. I've lived with verticillium before but had not seen it as extensive as this. As I recall, in SoCal area the info seemed to fit that there would be the most problem with especially cool and damp weather.....which is exactly what we have here. I do feel bad for my neighbor who finally got a couple of trees planted...maples...the front one large and probably a couple hundred bucks...I don't think I will tell her about maples and VW....she's already losing a coleonema....and she really is not a gardener, has not got that much planted...loves that Red Maple.

    Off to look at wikipedia......


  • wcgypsy
    Original Author
    8 years ago

    Thanks, hoovb.....I did check out the wikipedia list....quite good, very extensive...so extensive that I now see plants that will not be going in ground and some that are already in ground that I will worry about...oh well....it is interesting that the VW may not be evenly spread out, maybe currently affecting only certain areas since I have an old mixed hedge containing privet and it has not been affected.


    Also, BTW, I thank you for your excellent blog which I check into first thing every morning...miss you when you're not there with something new, so I hope your eye is not still giving you problems....

  • wcgypsy
    Original Author
    8 years ago

    Missouri Botanical Garden website also has a list of numerous plants, though I have not cross checked to see if it's identical to wikipedia's. The good news for me is that grasses are immune / resistant and with my love of grasses, I can / could probably plant those alone and be happy. It will work......one way or another...the luma apiculatas in the front border appear to be unaffected, though the halleria lucida in the center looks to be in trouble, but if it has to come out, it will just leave an opening for a path / entry there....

    The halleria.....

  • gardengal48 (PNW Z8/9)
    8 years ago

    "it is interesting that the VW may not be evenly spread out, maybe
    currently affecting only certain areas since I have an old mixed hedge
    containing privet and it has not been affected."

    Verticillium wilt is an opportunistic pathogen, typically only infecting plants that are under stress for some reason or another or have experienced some sort of mechanical damage. It is entirely possible for VW to be present and infect one plant with a susceptible neighbor untouched. I have seen it happen countless times with my horticultural consultation business and has even happened to me personally: a western redbud decimated by the pathogen while a cotinus only a few feet away was untouched.

    The pathogen is present in most soils, remaining dormant or inactive for decades until stimulated into activity by some underground chemical signal emitted by plant roots indicating stress, damage or other growth issues. If surrounding plants of susceptibility to the pathogen are not showing these signals, they can - and usually are - untouched. Just be aware that replanting in the same area with another vulnerable plant is a big risk as the pathogen is already awake and active and the act of planting itself is a cause of stress and very often root damage.

    I should qualify this as applying specifically to woody based plants (trees and shrubs) primarily. That is where my area of expertise lies and that's where most gardeners biggest landscape investments are concentrated. Farmers or those more concerned about herbaceous material may well have a different opinion :-))

  • wcgypsy
    Original Author
    8 years ago

    @ gardengal48...Thank You very much for your input and knowledge. In 30-some years at my previous location in San Diego County, I experienced VW only with the schinus terebinthfolius and I would cut out the affected branches and the trees would continue on. Nothing else there with extensive plantings was ever bothered, but I'm assuming that the dry climate helped.

    I'm glad that I've already planted extensively here, otherwise I would be afraid to plant anything except known resistant plants. As you say, not every plant may be affected. I do have multiples of lot of things and will keep 'back up' plants in pots. tubs in case. Fortunately for me, grasses are my great love and I've already planted a lot and could be happy with mostly grasses alone. I was not wanting to pull the halleria that looks like it's been hit, it will leave an open space in the front shrub border that I've installed for privacy and to block out a house across the road. There are luma apiculatas on each side of the halleria and they are unaffected, and again, fortunately, I have a third luma that is in ground just around the curve from these two and I can transplant it over to the space left by the halleria's vacating....LOL...I would rather have had something differrent in there as this is a mixed shrub border, but I already have the luma and it seems to be a safge choice. I don't have much faith in treating the soil there, but will do so anyway, just in case.....who knows? the newly planted luma may be vulnerable whereas the two beside it are not. The VW showed up in the one area after a colder and wetter Winter than the one before. I've planted dodoneas along a side fenceline to block out a too close house next door and they've done well, growing quickly as is their assigned task and I'm hoping they continue to do well.

    Thank You once again.....


  • gardengal48 (PNW Z8/9)
    8 years ago

    "I don't have much faith in treating the soil there, but will do so anyway, just in case.....who knows?"

    Unfortunately, you can't treat soil for VW control. Fumigation is really the only soil control method for this pathogen and that is not an option for homeowners.

    UCDavis has prepared this list of VW susceptible and resistant species common to many landscapes that may be of value to you.

  • wcgypsy
    Original Author
    8 years ago

    hahah..you've set my mind at ease...I'm yanking the halleria, which opens up a new pathway to the door anyway, and have dug out the sod from the old grass pathway to the door and am transplanting a third luma apiculata into that new spot, along with grasses which I already have. I plan on transplanting the luma today and was trying to make myself go see about something to treat the soil with...now I don't have to bother, thank you...I'm hoping that the luma, the other two of which remain healthy, will do okay in this new spot...it is closer to the problem area.


    I've checked online info as to resistant / susceptible plants and unfortunately a lot of what I'm growing is not on the lists so it's a crap shoot, I guess. I have a lot of potted stuff waiting to find spots and now I will probably plan on keeping a lot potted. I have a lot of new perennials sown in flats and those can be experimented with and woven in through my grasses, which, fortunately, are resistant.

    Two of three prostanterha cuneatas is now dying and I will dig the third today and keep it potted to see how it does. I see that penstemon is resistant and there are so many nice penstemons that I can plant in with my grasses also. It's all good...I'll live.......


    I've checked wikipedias list and Morton Arboretum's list and will now take a look at UC Davis's list.....thanks again....



  • wcgypsy
    Original Author
    8 years ago

    I have a number of Aussies and access to more from a friend who has been seeding his property in Pistol River to naturalize a lot of Aussies.....so, I've been searching online hoping to find a listing of resistant / susceptible Aussies. No luck so far, but an Australian organic gardening site states that using radishes and certain brassicas as a cover crop and hoed / tilled in are effective in fighting VW and also improve the soil which helps fight the VW also....hmmm...perhaps I will be sowing a lot of radish around the plants in my one bed currently affected...can't hurt....

  • gardengal48 (PNW Z8/9)
    8 years ago

    Not sure how they arrived at that conclusion as both radishes and brassicas are host species for the pathogen. So yes, it could hurt :-)

  • wcgypsy
    Original Author
    8 years ago

    and I just came home with radish seeds to baby my acer griseum planted this past Fall...LOL...guess I will have to go out and dance in the moonlight around it...or some other such ceremony to protect it.....at least I won't be forever hoeing in radishes...you are now my official VW guru....

  • napapen
    8 years ago

    try native plants and they may be more immune to VW.



  • wcgypsy
    Original Author
    8 years ago

    Maybe, seems that my romneya has already taken a dive.....