Fusarium - Ask Extension
This is my 3rd year for my asparagus. I noticed no asparagus was coming up in the center of my patch . I believe it root rot. Crowns have decomposed. ...
Knowledgebase
Fusarium #929127
Asked April 21, 2026, 3:10 PM EDT
This is my 3rd year for my asparagus. I noticed no asparagus was coming up in the center of my patch . I believe it root rot. Crowns have decomposed. Can you tell me the best fungicide to purchase in a garden store also granular to mix in soil. I discovered wet mushy dirt with reminates of crown
Clackamas County Oregon
Expert Response
Hi Colleen and thanks for your question about your asparagus. Unfortunately there are several possible causes for this decline, from viruses to Fusarium fungi and no home chemical treatments available at this time. You may want to get a soil test, as there are several soil problems that can be involved.
According to the Pacific Northwest Pest Management Handbook:
"High soil temperatures (optimum about 82°F) favor the Fusarium disease, which is more severe on plants in light soils. Low soil pH, poor soil drainage, or low levels of available Mn in soil may all favor disease. A high soil K to Mg ratio, if it creates a Mg deficiency, is associated with disease. These soil factors may negatively impact plant growth, making plants more susceptible."
Basically, this means you would want to have a soil test done in the area to see if any of these factors are involved before you plant more asparagus. We recommend the following companies but be sure to let them know you are concerned with asparagus:
*Simply Soil Testing https://www.simplysoiltesting.com/ (just for gardens & landscapes)
*A & L Western Labs https://al-labs-west.com/soil-analysis/ (garden packages but also serves commercial farmers)
*Western Laboratories, Inc. https://westernlaboratories.com/ (garden packages but also serves commercial farmers)
The problem may also be as simple as the very high temperatures we had a couple of weeks ago, so if you still have some areas doing fine, keep an eye on those areas and see if problems develop.
Since there is no way short of an expensive test to tell if the rotting crowns were virus, fungi, heat or soil stressed. I recommend getting the soil test and planting new crowns at a different area if the soil is OK pH and nutrient-wise. PH should be between 6.5 and 7.5.
You can get a free soil pH test at the Spring Garden Fair May 2,3 at the Canby Fairgrounds. The show costs $7.00 but is a great way to spend a day with over 140 gardening booths and lectures about raising different plants. Bring a baggie of soil from the area you want tested and they will tell you what the pH is. Asparagus is very picky about the acidity of the soil, so this could tell you a lot about what may be the problem.
Best of luck whatever you decide to do,
According to the Pacific Northwest Pest Management Handbook:
"High soil temperatures (optimum about 82°F) favor the Fusarium disease, which is more severe on plants in light soils. Low soil pH, poor soil drainage, or low levels of available Mn in soil may all favor disease. A high soil K to Mg ratio, if it creates a Mg deficiency, is associated with disease. These soil factors may negatively impact plant growth, making plants more susceptible."
Basically, this means you would want to have a soil test done in the area to see if any of these factors are involved before you plant more asparagus. We recommend the following companies but be sure to let them know you are concerned with asparagus:
*Simply Soil Testing https://www.simplysoiltesting.com/ (just for gardens & landscapes)
*A & L Western Labs https://al-labs-west.com/soil-analysis/ (garden packages but also serves commercial farmers)
*Western Laboratories, Inc. https://westernlaboratories.com/ (garden packages but also serves commercial farmers)
The problem may also be as simple as the very high temperatures we had a couple of weeks ago, so if you still have some areas doing fine, keep an eye on those areas and see if problems develop.
Since there is no way short of an expensive test to tell if the rotting crowns were virus, fungi, heat or soil stressed. I recommend getting the soil test and planting new crowns at a different area if the soil is OK pH and nutrient-wise. PH should be between 6.5 and 7.5.
You can get a free soil pH test at the Spring Garden Fair May 2,3 at the Canby Fairgrounds. The show costs $7.00 but is a great way to spend a day with over 140 gardening booths and lectures about raising different plants. Bring a baggie of soil from the area you want tested and they will tell you what the pH is. Asparagus is very picky about the acidity of the soil, so this could tell you a lot about what may be the problem.
Best of luck whatever you decide to do,
