i dont know what volume you are working at... but check out the link ...

some suggests that the driveway in august .. and black plastic bags.. might accomplish the same thing ... especially my blacktop ... you can nearly melt a flip flop in it at that time of year. ..

of course.. it will probably be the coolest summer in decades .. lol

ken

Here is a link that might be useful: link

Ken,

I have read about the black plastic bag method and have gotten conflicting opinions. Some say it works; some say it doesn't. My soil volume is too large to use the sterilization method in the link. I can't find any info on the web on this. Very frustrating!

Linda

Soil borne funguses can only be killed by heat. Since you can't do that you can keep it in the soil until it's gone. We had a problem with our tomatoes and VW. After 2 years of fighting it with little success we decided to mulch and that and careful vigilance worked.

We knew that it spreads with water. Water hits the soil and splashes on to the lower leaves carrying the virus with it. It works it's way up the plant the same way. The water carries it from leaf to leaf. We figured if VW can't get to the leaf from the soil it can't infect the plant.

We spread a 2 inch layer of fine cedar bark mulch as far out as the leaves would go. We trimmed off the lower leaves and when we watered we only watered the ground--never the plant. Every week or so we'd inspect the leaves and if any were infected removed them. We ended up with beautiful tomatoes with no sign of disease. In fact it worked so well we continue to mulch even though there is no sign any disease remains

You could do the same thing with your pots of flowers. It might only take mulching and removing any leaves that touch the soil when you plant

I believe VW can enter the root system when it is present in the soil. I can't find any info on whether this cold winter would have killed the spores present in the soil.

Linda

This post was edited by whitelacey on Fri, Mar 21, 14 at 2:02

As per the Penn State Extension..
"These fungi can exist in the soil prior to planting, may be brought in on planting stock, or may move in on wind-blown soil. The fungi can survive either in plant debris or free in the soil. The fungus enters the roots through breaks or wounds and moves into the vascular system, causing a systemic infection. After the plant or plant portions die, the fungus continues to survive in the soil for long periods of time. Factors that can increase disease are heavy soils and cold, wet spring weather.

Disease Management

Verticillium is favored by cool weather and is most severe in poorly drained soils following a cool, wet spring. There are no effective fungicides for management once the plants are in the ground."
They are referencing planting in the ground but pots would likely be the same. Lots of info on the Penn State site and other university extensions.

Thanks! I'll check it out.

Linda