Sick Boston Fern (frond breakage and leaf spots)

Asked January 4, 2020, 4:38 PM EST

This Boston fern has been indoors for about 13 years and was absolutely healthy and stunning until recently. It has always been planted in a self watering container, and I water it once a week with the same amount of water each time. We moved from Michigan to Minnesota and brought it with us in a truck together with outdoor plants. After a couple of weeks, it started to develop discoloring of leaves, mostly in the new fronds, which then fall out. More recently, I have noticed breakage of some fronds. Could you please tell me what could be causing this and how I could treat it? It would be really sad to loose it as it has been with our family for so long. Thank you very much

Olmsted County Minnesota

4 Responses

Several things come to mind. First and foremost, houseplants do not like to be moved. Leaves discoloring and dropping is a common reaction to a new location.

Second, generally speaking, Minnesota indoors will be drier and darker than Michigan. Boston ferns need high humidity, so growing this plant here may be problematic. Some people mist, but that can lead to disease transmission. A room humidifier might help more.

Finally, you didn't say what kind of conditions the plant encountered in its trip from Michigan. When did this take place? In winter? Was the plant left in the truck overnight?

If the plant is quite old, it might benefit from repotting. But I would wait until spring to do this.

If you eventually feel that your plant is a lost cause (the photos don't seem to indicate that), you can always try to propagate the plant. That way you'd still have a genetically identical plant.

Read here about growing ferns indoors in Minnesota:
This article has additional information:

Thank you so much for your response. I reported it last Spring and was doing wonderful. We moved to Minnesota the first week of October, and yes, it stayed in the truck overnight, with outdoor plants. My concern was a fungal or other infection from those plants.
Another concern is the hard water. We have not installed a water softener yet. I was planning to water it with distilled water and add a weak fertilizer as it is throwing lots of new fronds. Would that be OK?

The University of Minnesota Extension article I referenced in my first post has information about fertilizing. Too much fertilizer is a bigger problem with ferns than too little. I would not fertilize this winter, based on how the plants look in the photos. You can fertilize with weak (1/2 or 1/4 strength) fertilizer when the plants are actively growing in the spring.

The change in water may have also been an issue in your move. Hard water is usually less of a problem than soft water. Also, our tap water can be quite cold in the winter, which can damage tropicals. If you use it, let it get to room temperature first. Distilled water (or rain water) is best for all indoor plants. I'd avoid soft water.

Thank you dearly. I hope I can save him.