Avoid overwatering to prevent these issues. Asparagus fern's leaves will turn yellow if the plant has pests—like spider mites or mealybugs—or if your plant isn't getting enough sunlight.

Foxtail fern (Asparagus densiflorus ... Foxtails are not highly susceptible to bugs and pests, however, the mealybug and other scale insects could move in on a plant that is unkempt.