transplanting miscanthis (ornamental grass) and day lilies
Miscanthus - divide in the spring as soon as you see signs of active growth.
However, Chinese silver grass (Miscanthus sp.) is commonly planted as an ornamental but it has become invasive. https://www.bluewaterbaltimore.org/blog/invasive-plant-to-avoid-chinese-silver-grass/
Daylilies are tough plants. They can be transplanted/divided anytime but spring and fall are the best times.