Sword Fern Pests

Asked August 25, 2014, 1:21 PM EDT

Do you know of any pests that nip the very tips of sword fern fronds? There doesn’t seem to be a difference between ferns that are in sun or in shade, or ferns that get more water than others. All sword ferns in my yard seem to have the same problem. It appears that something is nipping off the very tip of the fronds. Happens to many but not all fronds. I will find just the very tip brown and dangling while the rest of the frond is green and vibrant. While I have checked both during the day and with a flashlight at night, I have not found any insects that are nibbling at the tips of the fronds. In any case, it doesn’t seem to be harming the ferns as all seem robust and healthy other than the dangling brown bits at the end of the fronds. Any clues? Duane Karstens Happy Valley, Oregon

Clackamas County Oregon horticulture

4 Responses

Young deer often try eating most anything until they learn what is good.

I'm pretty sure this is not deer damage. There hasn't been a deer seen in this area in the forty years I've lived in the area. There are the usual coyotes, raccoons, opossums, and various birds and reptiles, but haven't seen a deer in this neighborhood in a very long time.

I've attached a couple of photos so you don't have to depend upon my limited description of the problem.

Thanks,

Duane

Hi Duane-

Thank you for you question to Ask an Expert.

I do not suspect insects are causing this situation. To me, it looks like mechanical damage and I agree that deer could be a potential cause. Or kids?

The plants look very healthy and this damage will not affect the overall growth of the plants.

Please let me know if you have any further questions.

Weston

I have not ruled out mechanical damage, but as I do not have children, dogs, or deer the sources of mechanical damage elude me. (I'm pretty sure my cat is not biting the tips of my sword ferns) I have even considered heat and/or lack of moisture damage, but extra water on only a few of the ferns doesn't seem to make any difference. They still have the damage just as much as those receiving no extra water.

I agree that the plants are healthy and this doesn't seem to be affecting the growth of the plants. I'm just curious as to the cause.

Since you keep going back to the deer theory, and since I know that there are no deer in my back yard I'm just going to go with the assumption that you have never seen this sort of damage before and you just don't know what is causing it. My search for answers continues.

Thanks for your time.

Duane