I have a 25+ year old asparagus bed that has declined dramatically over the past two years. Production was low this year and about 70% has browned already (end of August). I believe it is fusarium and not treatable. I've attached some pictures to find out what you think. If there's a way to save the bed I'd certainly be willing to try. If not, I can try to turn it back into lawn but don't know the best way to proceed. Can you help me?
Montgomery County Maryland
We can't say for sure if Fusarium is causing this dieback. It is a possibility. If the beds have been in decline, you might want to replace these plants. We would recommend starting new plants in a different area, if possible. 'Jersey Giant' and 'Jersey Knight' asparagus are two types that are more resistant to Fusarium.
If you want to turn that area back into lawn, now is the best time of year to do a renovation. You will need to dig out the existing asparagus crowns, and then you can overseed the area with new turf seed. We recommend getting your soil tested first. This will give you the information on your nutrient levels, pH, and organic matter. This information will serve as a guide to amending the soil (for example, if lime should be added). Here is information on soil testing. https://extension.umd.edu/hgic/soils/soil-testing This page includes a list of labs to which you can send a sample.
Also, take a look at the following publication about lawn renovation, which includes all of the basic steps.