Ferns/macho fern turning brown, dropping leaves
QUESTION: Hi Dan,
I've read a couple of your answers about macho ferns. Mine may sound like another version of those questions. We have three macho fern beds in our yard. One under an oak providing deep shade. One under a Chinese Elm, providing moderate to light shade. The third is under a Peltophorum, providing moderate to light shade. The last bed under the Peltophorum is the one being stressed - all of the sudden the leaves are dry,brown and curling, not mushy, and dropping from the stems. The entire bed seems to be affected, though I can see an occasional new fern head popping up. This bed gets the same irrigation - so far this year, mainly from rain, and virtually no fertilizer except for whatever leaches from the lawn fertilizer once or twice a year. I'm ready to pull out or cut down the sick looking fronds, which is the entire bed, really. Any ideas as to what caused the problem, and whether cutting or pulling out is the better thing to do.
Thanks for your help!
ANSWER: Dennis hi;
My first question would be, where in the state are you and when did the damage occur?
If this is something recent (as in, last week), I would venture that your fern froze and then I would recommend doing nothing at all. However, if you think this is a chronic situation, then I could better address it if you would upload a few pictures (close and far) of the affected area.
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QUESTION: Thanks for such a quick reply! We're in Port Saint Lucie, southeast, north of WPB about a hour. No, we didn't get close to frost this year, yet, as far as I know. Nothing else in the yard is suffering. I'd say the drying/dropping began several weeks ago. Two images are attached.
Indeed, these ferns appear to have become 'blighted' with either a physiological condition, an insect pest, or a disease. Without a microscope or lab investigation, it would be hard to assess the causes.
I would still look at two alternative scenarios:
Macho ferns are very tolerant to a variety of shade conditions, but they must become acclimated. For example, if the overhead canopy has been trimmed recently, then existing 'shade' fronds would suffer but new ones would be OK.
Also, I would inquire whether they may have been hit with drift of herbicide sprays or even ocean spray.
If neither alternate suggestions rings potentially true, then I would suspect a pest / disease and would suggest a hard prune (all the way to maybe a foot down) and follow the new growth. If it's fine, then problem solved. If not, then your problem may have become vascular (existing within the plant) and the affected plants, as well as those around them, would need to be uprooted.
I would not suggest any type of chemical intervention without positive identification of the cause and, in any case, in a natural type setting as the one you apparently prefer.