Most ferns grow best in slightly acidic soils; however, maidenhair ferns prefer a more alkaline soil pH. Adding some ground limestone to the potting mix of container grown plants or mixing it into your outdoor beds will help with this
When growing maidenhair fern indoors, the plant prefers small containers and dislikes repotting. Maidenhair is also intolerant of low humidity or dry air from heating or cooling vents when grown in the home. Therefore, you will either need to mist the plant daily or set it on a water-filled pebble tray.
Caring for maidenhair ferns is not very demanding. While it needs to be kept moist as part of its maidenhair fern care, you need to be careful not to over water the plant. This can lead to root and stem rot. On the other hand, don’t let the maidenhair dry out either. But, in the event it does accidentally dry out, don’t be so quick to throw it away. Give it a good soaking and the maidenhair fern will eventually produce new leaves.
Read more at Gardening Know How: Growing And Caring For Maidenhair Ferns https://www.gardeningknowhow.com/ornamental/foliage/maidenhair-fern/maidenhair-fern-care.htm