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Invasive Ferns -- How do I kill them?

17 years ago

I generally love ferns. However, we recently bought a house with a 25 x 4 foot area covered in what I believe to be ostrich ferns. Whatever they are, they are incredibly invasive and spread quickly. They've spread into the adjacent grass, perennial bed, etc. I want to covert the "fern bed" to a flowering perennial bed and and looking for a way to kill the ferns for good. I've had no luck in pulling them and am wondering if anyone has had luck using Round-up each time a new plant emerges. I've tried to stay away from chemicals but it looks like I may need to use them. Any ideas would be helpful.

Thanks much,


Comments (26)

  • 17 years ago

    Have you thought of digging them up and either giving them away or ,heaven forbid, composting them?

  • 17 years ago

    Yep, lots of people buy them every year. You could sell them on ebay! Or tell people at work to come dig all they want.

    But I do think that repeated applications of herbicide would wear them down eventually.

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  • 17 years ago

    Ostrich Ferns are a wetland species and require moisture to survive. You might try covering the area with clear plastic sheeting and trenching around it to prevent water from running or seeping underneath the covering. Once their moisture source is removed, they will soon die. If the area receives some direct sunlight, the clear plastic will aid in sterilization of the soil, thus inhibiting any plant growth.
    Ostrich Fern growth is not sustainable in my garden, but a couple of other moisture loving Fern species, New York Fern (Thelypteris noveboracensis) and Bramble Fern (Hypolepis repens) have adapted to a much drier habitat and have become a weedy nuisance. According to Fern "experts", the Bramble Fern is a tender species and is not hardy below 20 Deg.F, but they have also adapted to much colder temperatures and send rhizomes out, up to 20-30 feet in all directions, much like your Ostrich Ferns.
    Good luck with controlling your problem. Digging and pulling them isn't the solution, I've found, as even a miniscule remaining section of rhizome will soon generate a new colony of ferns.

  • 17 years ago

    Hi, have you tried putting in a border of some kind around the ferns. That is what you have to do with running bamboo. It just has to go deep enough and high enough so the runners can't get over and under it. Then you could gradually decrease the size of the fern patch to nothing.

  • 17 years ago

    Have you ever thought about reconsidering your original idea? Rather than disturbing the entire area,why not just plant suitable plants among the ferns.Cultivating the ground will just encourage weeds.

  • 17 years ago

    Ostrich ferns may be a wetland species in nature, but they do quite well in ordinary garden soil that isn't too dry. They spread almost to the point of weediness in my own garden and left on their own, they would quickly smother and shade out just about everything.

    That said, they are fairly easy to control. Young plants come up very easily, but larger plants do take a bit of digging. If you're not in a hurry you could just mow them down, and keep mowing until they're dead. Or you could apply chemicals. But either way, their large woody/fibrous rhizomes would make the bed almost impossible to work, so you're going to need to dig them out anyway--as long as you have good tools, a strong back and elbow grease (and hopefully a helper or two!), a 25 x 4 plot is not that big and you should be able to get them dug out in a day or two.

  • 17 years ago

    They'er taking over! {{gwi:615186}}

  • 17 years ago

    I'll take a fern glade over a perennial bed any day. The picture above does not work. I really wanted to see this. I can hardly get ostrich fern to grow in Piedmont NC

  • 17 years ago

    I am wondering what sort of perennial flowers you are hoping for. Ferns mean shade. Shade means not tons of colorful perennials. I will be interested to hear if anyone posts who has tried to kill them with a systemic. Will the round-up follow the underground arms and kill the entire patch? No one has ever answered that query, and it has been asked before.

  • 17 years ago

    Thanks for all your comments. Arcy, the spot actually is quite sunny (southern exposure) and I'm putting in partial sun perennials -- even if it were deeper shade, there are many, many lovely perennials to use.

    We're doing the second Round-up application of the spring on this weekend and I've been told that we'll probably need to do 3-4 applications before the blasted things will die.

    I love ferns, but anything this invasive is not welcome in my garden. Well, maybe in a different (more wooded) setting, but not at this current site.

  • 17 years ago

    Most ferns like bright light rather than deep shade, and some, including ostrich ferns, can do quite well in sun if they have enough water. And as lulu5 points out, even in shade there are plenty of options for colorful perennials.

    Of course as I pointed out earlier, even after the ferns are dead, the rhizomes will pose a problem. They will produce excellent soil if allowed to decompose in place, but I suspect you don't want to wait 2 or 3 years!

  • 13 years ago

    My daughter in law recommended clorox bleach.I am going to try that.I dug up twenty last year and gave them away, and, It looks like there are twenty more this year. I was hoping for some other ideas.

  • 13 years ago

    Beware that spraying chlorox bleach may have adverse health effects. Your lungs can suffer permanent damage from just a small amount of aerosolized chlorine.

    As a gardener, you are part of a connected web of life. What you harm in your environment can also harm you.

    Use a nice heavy flat tined garden fork. Gently pry the soil up to loosen it and remove as many of the brown woody rhizomes as you can. Do this when the soil is moist.

    Using the clear plastic cover after you do this will sterilize any weed seeds you may have brought to the surface.

    Otherwise, you are fighting a losing battle. Chemicals are not necessary.

  • 13 years ago

    Plants are not invasive if they are native to the continent in which you reside. Native plants of course can become a nuisance if planted in the wrong location. I am not trying to be a jerk for saying this, it is just that many people do not use that term appropriately. It is an important term and needs to be used in the proper context regarding all the crap plants that have been introduced to North America because they were pretty or served some other inane purpose, or were unknowingly or unintentionally brought here.

    I am against chemical use as well, because of the harmful effects it has on the environment and to people's health. If you are not willing to do the work, then why change anything? If you are physically unable to do the work then maybe consider paying some enterprising kid to dig them out for you. Or post on Craigslist or the grocery store bulletin board, or spread the word with neighbors and friends offering you-dig-'em you-take-'em. That should at least get you started.

    I have had to remove Ostrich fern colonies that turned out to be in the incorrect location. It is hard work initially and the project can take 2 years but it can be done. Dig out the plants, dig out as many rhizomes as possible, then lay old carpet or some thick plastic down (or better yet do both). Put some stones on the carpet or plastic to keep it in position. Let it sit idle for two years.

    I apologize if I hurt your feelings but in my opinion the problem is not the ferns, it is that you do not accept that this project is going to take time and effort. You want them gone NOW so you can start your new garden, which I can totally understand. In your situation a little patience is going to have to be practiced.

    Or if you just want this project to be over and done with, then simply pay someone to take a skid loader and scrape off the top six inches of soil and ferns and have it all hauled away and dumped at the local compost site. Then add six inches of new soil mixed with compost. Done in a day and it is ready for your new plants and your new ideas.

    Either way, try to skip the chemicals.

    Good luck,

  • 12 years ago

    Bleach is one of the safest things you can use to eradicate unwanted plants/weeds because it does not persist for any length of time in the environment. I use it to kill weeds in my driveway and here and there in unwanted areas. Try not to get it on plants you want to keep, but if you do just rinse them with some water, diluting it renders it harmless. Round-up or most other store bought herbicides are a different story. I work in an environmental office for an organization and that's what we recommend to the people who work at our many facilities for weed control.

  • 12 years ago

    My neighbor's ferns have come under the fence and are spreading EVERYWHERE. They are going under and through concrete and all seem to be connected by what I call a root system. It runs DEEP! I have pulled the tops, dug out huge sections of 'roots', and done one application of Roundup. They scoff at my efforts and continue to spread. I have come to hate ferns like this. And I generally love most plants. My back is trashed and my spirit weakened but I WILL NOT GIVE UP! I don't even know what they are. They send up single fronds all over...

  • 12 years ago

    Andrea, sounds like Bracken fern. See if that is found in your area.

  • 12 years ago

    The last time I sprayed clorox on the ground I was trying to kill algae on a brick sidewalk, and I sprayed it right onto a baby toad. I tryed to catch him to wash him off, but couldn't. That guilt has haunted me for years!!! NEVER spray anything on the earth you wouldn't put on your own baby.

    Also, I can't imagine trying to get rid of ferns...they are my favorite plant.

  • 12 years ago

    >NEVER spray anything on the earth you wouldn't put on your own baby.

    Seriously? Good grief. You're nuts.

  • 12 years ago

    Bleach is one of the safest things you can use to eradicate unwanted plants/weeds because it does not persist for any length of time in the environment.

    It is amazing the amount of misinformation that gets spewed about online. Unfortunately, a lot of it remains there unchallenged and picked up, repeated and recycled and worse......often acted upon, to the detriment of our environment and sometimes ourselves.

    Chlorine bleach poses a significant risk to the environment, and chlorine was even used as a chemical weapon during World War I. Many countries have banned chlorine bleach or restricted its use in an effort to protect the environment and human health.

    As an example of bleach's persistence in the environment, manufacturers who use chlorine bleach as part of the processing, cleaning or sterilization processes often release it into local water bodies along with other liquid industrial waste. Once it reaches the water, chlorine reacts with other minerals and elements to form a host of dangerous toxins. These toxins, including dioxins, furams and PCDDs are often referred to as "persistent organic pollutants" because they linger in the water or soil and take many years to disappear. Greenpeace calls dioxin one of the most dangerous chemicals known to science, and warns that it can contribute to cancer, endocrine disorders and other serious health effects. The West Virginia University Extension also links chlorine-based compounds, like dioxins, with low sperm count, testicular cancer and breast cancer due to their ability to mimic human hormones. So you guys who are so ready to start spraying chlorine bleach all over the place may want to reconsider your choices :-)

    DON'T use bleach as a herbicide. It is not registered for that purpose so technically it is illegal to use it in that manner. Second it is a caustic, corrosive agent that is damaging to all manner of beneficial soil insect life, amphibians and aquatic life and any mammals it might come into contact with. It is also extremely alkaline and can negatively impact soil pH, making it difficult to grow any plant in any area so treated.

    If you must, use a registered herbicide - like RoundUp or similar - according to label directions.

    Here is a link that might be useful: bleach is not a herbicide

  • 11 years ago

    NEVER spray anything on the earth you wouldn't put on your own baby.

    Does this mean I can't even SPIT on the ground?!

    But seriously, gardengal's post is correct, if a bit alarmist. Bleach is a pretty hamfisted way to kill weeds. Roundup is, on balance, less threatening to the environment...but it must be pointed out the net amt. of chlorine you'd add to your garden from using hundreds of gallons of municipal tap water would be just the same as using a couple gallons of a 0.5% bleach solution on some weeds. I've notice some plants don't really thrive on municipal water. It keeps them from dying, but they only grow vigorously with rain water or my non-potable well water. Alkaline sodium salts are added to tap water too, to stop the corrosion of copper pipes. These will build up to some degree, until washed out by rain water or displaced by other ions like calcium. In fact, the reason gypsum "fixes" clay soil is because the calcium causes the clay nano-particles to clump into larger groupings; sodium (which can have been present in the soil for millions of years) is displaced in this exchange.

  • 7 years ago

    I don't mind digging them up, but they invade other plants and come right up in the middle of other stuff. It appears you can only enjoy them if you can keep them isolated in their own confined areas.

  • 3 years ago

    We have just moved to WV We have unattractive ferns that cover the yard. Have used Roundup over and over on them their fronds(?) go deep DEEP into the ground and below them are many baby ferns just waiting to invade our yard. They are the only thing I have been unable to kill. With one arm I cannot seem to get them all dug out and to me, these are very unsightly.

  • 3 years ago

    I planted daylilies with ostrich ferns, which seem to be in a stable balance five years later. Hostas succumbed. The daylily/fern scheme was one I saw on the bank of the quarry of Russel Wright's house, Manitoga, in Garrison, NY.

    As for bleach, I've been spraying a solution of it on all the groceries. Now I'll have new nightmares.....

  • 3 years ago

    It occurs to me to mention another plant that i would never have thought would be 'invasive'. Common milkweed. It has a strong rhizome that appears to travel quite a distance, and seems to be located a foot underground, and pops up here and there, which might be in a garden with other plants in it.