PlantFiles: Southern Sword Fern, Narrow Swordfern, Erect Sword Fern, Ladder Fern, Tuber Fern
Nephrolepis cordifolia

Although the Ladder Fern is a handsome looking plant, it is listed in the National Pest Plant Accord, and can not be sold, propagated or distributed in New Zealand. It can grow to 1m tall, and is the only fern that has tubers. It spreads through its spores, runners and hairy potato-like tubers, growing almost anywhere and under any conditions, and in any soils. It can be all invasive crowding out groundcovers, shrubs, other ferns and plants. The runners and tubers need to be disposed of properly.

I planted three small clumps of this fern from pots when I first bought our house; I have always loved the way ferns look. But they have spread everywhere and they seem to make it hard for anything else to grow where they are located. I have/had them planted around some of our trees, and I suspect they may have accelerated the demise of at least one of them. I have found the roots burrowing into the base of some of our big oaks and one of the oaks that fell over recently and was rotten in the center (unbeknownst to us, it looked fine) had ferns all around it and I could see the roots on the inside of the stump, having burrowed right through the outer layer of the tree.

I still think they are pretty, but they need to be aggressively controlled and isolated from other plants, in my opinion.

Yes this plant can become invasive IF planted in the ground. I would not recommend doing so. It is a wonderful fern in a pot though. Much easier to grow than other ferns, and certainly not finicky. Every few years I just lift the fern out of the pot and thin them out. This keeps them looking nice. Doesn't require much maintenance other than that.

Although considered invasive by other gardeners, I have found the spreading habit of this this plant beneficial. It makes great borders around trees where no grass will grow & fence lines to keep grass & weeds out.
Is easily mowed or pulled out if growing where it is unwanted.

Although a beautiful fern, it is a PEST plant in my area. I can't tell you how many thousands we've pulled out of the yard over the last twenty five or so years. I made the mistake of getting one small plant from a friend years ago and now I can't seem to get rid of it totally. It spreads like crazy ... sorta like a bad rash! Makes a lovely hanging basket house plant but I would advise anyone living in zone 9 (possibly 8!) to deter from planting this in their garden unless they want it taking over and crowding out everything in sight!

This is just about the most invasive plant I have ever introduced into my garden. It knows no limits (except it will burn back in hot, direct sunlight). It will bulldoze away any plants in its path as it spreads. Further research needs to be done, I think, to determine if the plant roots have an allelopathic ability to kill other plants. I greatly regret that I ever planted it, but I did so when I was more of a newbie gardener.

This plant is sometimes confused with Boston Fern (Nephrolepis exaltata 'Bostoniensis'). In fact, some unscrupulous or uninformed plant nurseries will actually be selling N. cordifolia in hanging baskets labeled as "Boston Fern" when the plant is actually Sword Fern. There are several botanical differences between the leaf structure of the two ferns, but the differences are generally so small that only a trained eye would recognize one from the other. However, one glaring difference makes it easy to tell them apart. The N. cordifolia (invasive Sword Fern) has spherical tubers on the roots; N. exaltata 'Bostoniensis' does not have these round tubers. Before buying anything labeled as "Boston Fern," I would recommend lifting the fern from its pot or hanging basket in order to inspect the roots to see if the round tubers are present. If the round tubers are there, the plant is most likely Sword Fern and is being misrepresented as Boston Fern.

Jeremy

In North Carolina and other southern states large hanging baskets of this are coveted by many for hang outside on big porches and displayed on pedestals. It is hard for most to keep it looking good, but they try.

Here in Florida it's everywhere, making a soft edge to everyone's gardens. I yank out a bushel every time I go outside to work. It has little "cocktail onion" at its base from which small hair like roots grow from and establish it shallowly in the sand. This pulls up easily, but also grows back when you turn around.

When we have a freeze it does insulate some of the other plants just by its dense presence.

This is on Florida's invasive plant list. I can mark it negative, but that because it is impossible to be rid of it here.

I have grown sword ferns several times.. very hardy here in hot, dry southern CAlifornia... and quite invasive... though have to admit pretty easy to yank out of the ground. Not sure how it does in other climates, but always looks sad after Santa Anas, and winter... half to all the stems die leaving a bunch of sticks as the new ferns come up... makes a messy, unattractive look and requires a lot of work to get things looking nice again.

It is grown very commonly down here and sold all over as an indoor as well as an outdoor fern. Spreads like wild fire.

Tufts of finely toothed sword-shaped fronds rise from short, erect, hairy leaf stems. It will grow to 2-3 feet tall. The spores are visible on the underside of the leaf, but this fern mainly propagates by spreading hairy runners. It does best in shade but will take sun if given ample water.

I have lived in zone 9b for 22 years and gardened here for most of those years. Erect sword fern can be seen many, many places doing quite nicely. It is considered invasive by some, and when put in the wrong place it certainly can be. You can mow it occasionally without harm to the plants, and it is a dependable ground cover in shade here, wherever there is woodsy soil. The more rich the soil, the more lush the ferns and the farther they'll run.

I like this plant. I have yet to release it in my new garden, because I know what it is capable of. But I will, because I know what it does for woodland settings.