I moved two large ‘ruffles’ variety ferns and two asparagus ‘plumosa’ inside my apartment at the end of fall to keep them over winter. When I brought them out of isolation, they looked healthy. They are 1 1/2 feet from an east-facing window (which has less light as it is under an overhanging balcony), and are on their own individual pebble trays. However, after 2 months inside, their fronds are becoming brown and dry, starting from the bottom, not the tips. As I had kept one of the plumosas over winter last year in the same place, what can I do to get it and the others to survive until it is warm enough to put them outside on the balcony again? I know I can buy new plants in spring, but I do like them inside over winter.
Thank you for your advice,
You have two very nice ferns which thrive both outdoors in a frost free environment and as house plants: Asparagus fern (Asparagus plumosus) which is not a true fern but a member of the lily family, Liliaceae and Sword fern ‘Fluffy Ruffles’ (Nephrolepis exaltata ‘Fluffy Ruffles’) . Both have specific growing conditions, some of which you have met.
Your asparagus fern will grow indoors in filtered sun or bright, indirect light. However, special attention needs to be paid to the humidity level around your plant. Placing a pebble tray with water under the plant is an excellent step to reach a humidity level of 80%. Unfortunately our indoor environments are so dry in the winter, you may need to give it a daily misting as well.
During winter months, the soil should be kept dry to the touch. Leaf drop will occur with too much water. Weekly feeding with half strength balanced fertilizer is only required during the growing season from spring to fall.
‘Fluffy Ruffles’ grows best in full to partial shade and in organic-rich, well-draining soil with regular moisture. They are somewhat drought tolerant and during winter months, water should be somewhat restricted. Do supplement the humidity levels indoors. They are vigorous growers and should be re-potted on a yearly basis.
Browning of the fronds can be caused by a number of conditions. Perhaps the light conditions are not high enough. An east window under a balcony overhang in the winter may not provide enough light. You may want to try another window location.
If you did not fertilize your fern regularly during the summer, it may be lacking nutrition, specifically nitrogen. Give it a half strength balanced fertilizer once or twice this winter and then fertilize regularly during its growing stage.
Your plant may have outgrown its pot and need to be replanted into a larger one. Pull it out and check the root growth and soil availability. Root growth in a circular manner around the pot indicates that the plant is pot-bound At the same time, inspect the roots. If they are black and slimy, root rot is causing the yellowing. Prune the dead roots, cut back on watering and change to better-draining soil. If it is severe, you will have to replace the fern.
A third possibility is a spider mite infestation. If the fern foliage has a speckled look, spider mites may be the cause of yellowing. Increase the humidity and watering and spray with insecticidal soap.
Good luck with your ferns. They will look lovely on your balcony next summer.