I am sorry for this delayed reply to your gardening question. The spring rush has brought a deluge of questions and we are working hard to catch up!
Most ferns do prefer humidity but other than installing a mist system there is not much you can do to increase humidity. Water them as needed to keep the soil moist. This may be anywhere from once or twice a day to twice weekly depending on sun exposure, temperature, etc. If you spray the foliage use distilled water or rainwater so the deposits in your water don't leave white residue on the plants.
Thanks for the question. Best wishes for a wonderful gardening season. Please stop in again soon!
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