Experts and BHG readers answer.
Where to plant mosquito fern
Does your plant have any other name that you know of? The reason I ask is that the common name mosquito plant is generally used with a floating water plant that's very invasive, but clearly can't be what you have since you are talking about it invading daylilies. If you don't know of another name for the plant, can you give us more information? What does it look like? Did you plant it or is it a native? I'm so sorry I can't be more helpful, but common names are often confusing and not helpful.