In rare cases, cover crops or neighboring species of weeds can act as secondary hosts for the sexual stage of P. capsellae. P. capsellae overwinters as thick-walled mycelium on infected detritus in fields, and germinates again to infect new hosts as conditions become more ideal for spread.
In exceptional instances, cover crops or nearby species of unwanted plants can serve as supplementary hosts for the sexual phase of P. capsellae. P. capsellae survives the winter months as a thick-walled mycelium on infected decaying plant material in fields, and re-generates to infect new hosts when conditions become more favorable for dispersal.