Vercillium wilt

[bobm]

Remember about 2 weeks ago, I purchased 10 maple trees from a commercial maple nursery that was selling off all of their trees at their retirement sale. I started to plant the trees right after I got home and finished the next morning. Three days later , 5 of the trees' leaves started to droop and the edges started to turn brown. A week later all of the leaves turned brown. I called the nursery owner who said that to stop watering as the maples in this area like to be on the dry side. Also to dig back up a couple trees to see how wet the root zone was. I did so, and found the soil just moist. A few days later there were several black rings forming on branches and trunks. I just came back from the Washington State Extention Office/ Farm in Vancouver, Wa. ... the tree expert / Master Gardener person identified the culprit as Vercillium wilt ( Vercillium dahliae ) that affects maple trees as well as a host of ornamental and crop plants. I was told that eventually my maple trees as well as most of my other plants will succumb to this pathogen. . The other sad part is that this commercial maple nursery has sold over 4,000 maple trees to other nurseries in Washington as well as to other States, and they donated several thousand 1, 2 1/2 , and 5 gal. plastic containers to WSU Master garden program at their plant propagation to tutor new master gardeners and then sell those plants at their annual plant sales. For a list of susseptalbe plants as well as chemical warfare that is needed to limit this pathogen ( natural control methods are futile ) , I would recommend that you all ( especially DigitS and Thistlebloom ) Google " Vercillium wilt in the Pacific North West" . WSU Master gardener folks will start to inform of this outbreak situation their memebership and contact other purchasers of the maple trees and sterilize/ fumigate all of their container pots,all other equipment, trucks, tractors and storage areas .

 

[thistlebloom]

I have dealt with trees in landscapes that are potentially stricken with verticillium wilt. I say potentially because the only positive ID is through a lab analysis.
It's really not the end of the world. It does stay in the soil, so if you have it, then you have it. As I understand it from conversations with certified arborists, the soil fumigants are not always reliable in eradicating it.

If I had it in my own soil at home I would forgo chemical fumigation of my soil. Just my viewpoint.

There are several trees on different properties that I care for that have started a slow decline, and have been identified as probable victims of VW. The owners did not opt for a lab verification.

I use a tree treatment on them and in every case the following year the tree has perked up and begun putting on new growth. I don't think they're "cured", but it has helped the tree fend off the effects and given them at least several more years in the landscape. It's also important to give those trees every advantage by making sure they aren't planted too deep, not over watered or allowing the bark to get hit by sprinklers, and if they are in a lawn, never to use a weed and feed product on them.

I hope your trees survive Bob.

 

[bobm]

Thistle, what did you use as a treatment for the trees ? My 5 trees first showed signs of a problem with wilting and edge browning of their leaves, now, almost 2 weeks later one tree, which I took to WSU ,is 99.8% dead as all of it's leaves are dead and almost all of it's trunk and branches are black with just a few small areas that are still brown/ black and a very small area of green trunk. The other 4 are between 75%- 50% black/ brown with all of their leaves dead. The tree expert/ master gardener is a professor of horticulture for about 30 years field and teaching experence and is the head instructor for the Master Gardeners. So, I tend to listen. I have no sprinklers nor a lawn. What water they get is from the big sprinkler from the sky and some hand watering in the summer once a week when we get next to nothing from end of May to late Sept.

 

[thistlebloom]

If it happened that rapidly then nothing you do will be likely to help.
Sorry about the loss of your trees. Japanese maples seem to be extra sensitive to VW.