Blight and raised beds

ScottinAtlanta · September 27, 2011

Folks, I had late blight this year. I am putting in raised beds for next year. If I cover the existing soil with cardboard, and build on top of it, will that reduce the risk of blight next year? Or will worms just travel between the layers and carry the spores?

RayR · September 27, 2011

Late Blight is not soil borne, it needs living plant tissue to survive and the spores are transmitted through the air.

ScottinAtlanta · September 27, 2011

Thanks, Ray. Will a raised bed change the risk of blight at all?

bcday · September 27, 2011

Covering the existing soil with cardboard and building a raised bed on top of it won't have any effect at all on the risk of late blight next year. Any late blight your plants get next year will not come from your soil unless there are infected potato tubers there that won't get frozen over the winter.

The spores can't stay viable in the soil independently over the winter. They die quickly without a living plant to grow on.

If you didn't grow any potatoes and all your other host plants are dead, then any late blight spores in your garden will also be dead. It doesn't matter if worms and other critters in the soil carry dead spores around. Dead spores can't infect your plants.

Late blight spores are very light and are carried from infected plants into your garden on the wind. The source could be miles away.

ScottinAtlanta · September 28, 2011

Thanks, that is good news indeed. I appreciate everyone's time in responding.

Robert Brenchley · November 24, 2011

The source could be miles away, but often it's very local. Be ruthless about rooting out volunteer potatoes and you increase your chance of escaping the disease.

September 27, 2011	#1
ScottinAtlanta Tomatovillian™ Join Date: Jul 2011 Location: Atlanta, Georgia Posts: 2,593	Blight and raised beds Folks, I had late blight this year. I am putting in raised beds for next year. If I cover the existing soil with cardboard, and build on top of it, will that reduce the risk of blight next year? Or will worms just travel between the layers and carry the spores?

September 27, 2011	#2
RayR Tomatovillian™ Join Date: Jun 2010 Location: Cheektowaga, NY Posts: 2,466	Late Blight is not soil borne, it needs living plant tissue to survive and the spores are transmitted through the air.

September 27, 2011	#4
bcday Tomatovillian™ Join Date: Jan 2006 Location: NY z5 Posts: 1,205	Covering the existing soil with cardboard and building a raised bed on top of it won't have any effect at all on the risk of late blight next year. Any late blight your plants get next year will not come from your soil unless there are infected potato tubers there that won't get frozen over the winter. The spores can't stay viable in the soil independently over the winter. They die quickly without a living plant to grow on. If you didn't grow any potatoes and all your other host plants are dead, then any late blight spores in your garden will also be dead. It doesn't matter if worms and other critters in the soil carry dead spores around. Dead spores can't infect your plants. Late blight spores are very light and are carried from infected plants into your garden on the wind. The source could be miles away.

September 28, 2011	#5
ScottinAtlanta Tomatovillian™ Join Date: Jul 2011 Location: Atlanta, Georgia Posts: 2,593	Thanks, that is good news indeed. I appreciate everyone's time in responding.

November 24, 2011	#6
Robert Brenchley Tomatovillian™ Join Date: Jul 2009 Location: Birmingham UK Posts: 31	The source could be miles away, but often it's very local. Be ruthless about rooting out volunteer potatoes and you increase your chance of escaping the disease.