Mold or root rot?

For the last 2 yrs ive had a couple of plants get a weird white mold on and around the stalk where it meets the ground. It would slowly kill the entire plant, the mold diddnt look like it spread from the base of the plant but something happened! Yesterday i was turning the dirt over in the bed and started noticing alot of lil roots with white mold on them, is this the same thing that is killing my plants or is this normal during the winter months? PLZ if anyone has any input i would like to hear it. Would spraying the dirt with milk and peroxide help any?

do you use the same soil? and do you use mulch by chance? does it occur in more than one location? if so and you use the same soil and other products you can begin to figure out the culprit. some fugal problems occur from mulch i have very limited knowlege but i would start by changing the soil and mulch (if used)
do you have any pictures by chance? definitly don't spray with milk or straight peroxide, there must be better solutions. let me know about your soil and whether you use mulch and is so what type of mulch. and we can go rom there ok.