Thanks for your question! There is a new factsheet, "Jumping Worm (JW) Bast Management Practices" that was just pulled together at the University of Vermont and published in May 2024.

https://uvm.edu/sites/default/files/Extension-Community-Horticulture/Resources/JWBMPfactsheet.pdf

That factsheet has a whole section devoted to the most effective and practical treatments. Mustard is not a suitable treatment for jumping worms, but it can help you identify if you have them present in your garden. 

Mustard test: Using a liquid “mustard pour” is a way to test for jumping worms. Mix ⅓ cup of ground hot yellow mustard seed (look for Chinese or Asian hot mustard) into 1 gallon of water and pour half of the liquid slowly over a 1 square foot of soil you want to test. Wait a few minutes and pour the rest. This will make worms (any earthworms) come to the surface. Identify, collect, and discard jumping worms, if present. The mustard solution will not harm plants or kill the worms. More info: https://extension.umd.edu/resource/invasive-jumping-worms/ 

Unfortunately, research is still underway to determine effective methods of control. If your property is infested, it may not be practicable to eradicate JWs, but you can manage the ecosystem to reduce negative impacts. Measures you can take include: reducing the worm population (see below), investigate plants that are less susceptible to JWs soil disturbance, and planting species with varying root depths. Some pesticides are being evaluated on JWs, but not legal to use. Adaptation does not address the root problem of invasion and may not be sufficient to prevent long-term ecological changes. 

Feel free to reply to this message if you have more specific questions about JWs on your property!