Perennial "Pests"

...The Plants You've Grown to HATE!




I would like to hear from you about what your most HATED perennial plants are...those that looked so sweet and innocent before they took hold in your yard and now you can't get rid of them! Please include your gardening zone and soil type. You can email your responses to me and I'll post them here. Ranting and raving is allowed (as long as you keep it clean)! If you don't know the botanical names of the plants, please don't let that hold you back...if we're not sure of what the plant is, we'll probably figure it out if you describe it! (Especially if it's something we've also struggled with.)

I'll go first (zone 8, sandy soil). I have a couple that I'm still fighting. I'd planted Artemisia 'Silver King' when the perennial bed was new and in one season it went from a small 2" pot sized plant to a diameter of about 10'. Eek! I pulled it immediately and managed to get rid of it. Two plants that I still am fighting are Sweet Woodruff (Galium odoratum) and an unknown variety of Campanula (maybe rapunculoides?). I didn't plant the last one. It stowed away in the root system of a plant someone gave me (interestingly enough, she warned me about the plant and had complained bitterly about its presence in her yard). There was no indication that I had anything other than Doronicum and after I realized the Campanula had hitched a ride, I dug up the host, completely cleaned the root system, replanted and in one season IT WAS BACK (and it still comes up after I've tried to eradicate it)! The Sweet Woodruff is really charming, but it insinuates itself in the root systems of its neighbors and tends to take over if there are small, slower spreading plants around it. It would be okay with hostas and the like, but I decided it was a mistake after planting and have to pull it each season. It comes back enough to be charming, but if I stop pulling...it will be off to the races!

-Kathy Miller-

Date: 4/29/2007
From: Paula

I am in NW Oregon, zone 7-9, (this is Oregon, what can I say!) Clay soil, though I amend as I go with OM... still pretty much CLAY. My invasive plant is Dicentra Eximia or "wild bleeding heart." I DO still love it, even though I fight it constantly! It's low growing, lovely ferny grey-green leaves and flowers ALL thru spring summer and fall. BUT, it just APPEARs everywhere! I'm thinking that it MUST reseed. I had it in upstate NY and it was SO well behaved. In a land (Oregon) that it seems every plant has a wild cousin growing, I'm realizing that potting many of my plants is a wise choice!

Paula :P

Date: 6/23/2005
From: Debra Reames

Hi there,
I'm in Maryland, zone 7a (bordering on 6). I'm a pretty easygoing gardener. I encourage a lot of what are considered weeds because they are pretty or useful. For instance, I actually transplant ground ivy (creeping charlie) to crowd out other less interesting weeds. I like my vinca and my sweet woodruff; had no trouble with forget-me-not (wish mine would thrive more); etc. I'm fighting the good fight against the mint which was planted by a previous owner and I think we might be slowly winning that one.

But My WORST choice EVER was planting Tansy in my herb garden! After 2 years I completely eradicated the herb garden (which was mostly Tansy at that point) by plowing, raking, and covering with heavy black plastic and mulch for over a year. Since then, the entire yard has been professionally landscaped (including filling in the slope that the herb garden was on) and 3 years later I am STILL pulling volunteers up!!! It's the Freddie Kruger of plants -- it keeps coming back!

I actually went down to Williamsburg to see how they dealt with it since I knew that Tansy was a popular medieval and colonial herb. Wise gardeners that they are, their tansy is planted in a tall clay pot (a long-tom) that is then sunk into the ground in the sample herb garden.

Thanks for letting me vent!

D. Reames

Date: 5/02/2005
From: Jen

not much will grow here in the desert so a lot of the plants that your other gardeners are complaining about i wish i could grow. The one that i have had the most problems with is mexican primrose. Beautiful pink flower that smells like lemons and is extremely drought tolerant. The next pest i would like to label is st. johns wort, sprayed it with every killer i have and it is still going strong, i might just give up and fertilize it and have something lush in that area of choice. Last but not least is the herb lemon balm, however i like this plant, but it does reseed excessively. the biggest pest i have is mint, but i decided to let it grow through my grass and every time we walk on the grass or mow it, it smells soooooooooo good. thanks for reading and happy gardening to all of those out there!

high desert gardening in ca

Date: 10/9/2001 9:52 PM
From: L. Goudeau

A few years ago, I went to a prairie wildflower seminar in Eunice, LA. Among the edible plants offered was something called "Cajun Radish". It was the white root of a plant, and quite tasty. I took some home and planted them. When I proudly told a friend of mine who was very knowledgeable about edible plants, she told me these were "stacys" and to dig them up immediately and plant them in pots only, because they were very invasive. I did, but alas, too late. I have been fighting them ever since. They are not even tasty anymore, because I hate them so much.

If the stem breaks when the plant is yanked out, the root simply sends up another plant. This plant also flowers, and reseeds itself. It's only hope for salvation is: if ever there is nothing else to eat, I can always eat this. I did not go through all the pages, and wondered if anyone had mentioned bamboo. It's my other pet peeve.

--- L. Goudeau

Thanks for your email! I don't know when I'll get the updating underway... but your mail will be saved and posted as soon as I can get to it (making a lot of soap right now). :-)

I wonder what this is... did she mean "Stachys"? That is a particular plant family. I'm wondering if these were Jerusalem Artichoke? I've heard of that and know it is edible but very invasive. My cousin planted some ONE time. ;-)

Happy gardening... glad you enjoyed the web page!

Date: 9/21/2001 11:17 PM
From: BrendaSue Solheim

Hi from Eagle Grove IA...

I live in Zone 4, & it is pretty much black soil here. We live on a acreage, & it was a gardeners dream. As I was getting started, it seemed my brothers thought they should help. Little did I know that they brought seeds & dropped them in my largest flower bed. Chinese lantern, which I just hate. As if you don't catch it before it seeds, next thing your finding it all over the place. Also vinca. I couldn't figure out what this was, I just thought it was a weed. Little did I know at the time, that if you even dropped a little itty bitty piece of it, would start rerouting itself once again. Every time I am in that big garden, I cuss under my breath at my brother. Thanks to him, I think of him often.

Two years ago I was riding with a friend, & we asked someone if we could have a sample of a gardeners nightmare. Tall phlox. Geez, I only brought home one plant, next thing I knew it was everywhere in the garden. I have now figured out the plant identity in the spring, & have started removing it early. As the root system is darn hard to dig out. About a month ago, I dug up 30 of these plants, & put them in the ditch, lets just hope that is where they stay, & don't find there way back into my garden beds.

Last fall I took the master gardeners course in our area, boy did I learn quickly what was invasive!!!! Boy, had I wished I taken this course when I first started gardening, it sure would save alot of the headaches I am having now. LOL..

I found that the yarrow/bee balm/obedient plant, new England aster are all very invasive. Can pull it all you want, as it sure isn't going to go anywhere. I have decided the easiest way to get rid of those things I don't like, is pot them up & move them out in the spring. I am sure some new gardener will love to try a sample. I have decided, that it is just easier to start a new flower bed, & spray this 30' by 30' bed with round up once I move all the plants I love. I have tried long to get rid of that vinca, plox, bee balm.

I learned through master garden course, that if you want to try & contain the invasive flowers, cut the bottom of a pail out, & put it in the ground, hopefully they won't jump over it. Otherwise look it up before you purchase it to see how aggressive it can get. Also cutting the flowers back before they drop there seeds may help, but that isn't always a sure way either.

Alot of people don't like the snow on the mountain. Now when friends want theirs dug up, I am ready to go get it. I planted some of that two years ago, for ground cover in the grove & it hasn't done a thing. I dislike mowing in between the rows of trees. Thought this would be a great ground cover, & maybe it would just take over. I am sure one of these days I will wake up, & it will surprise me with taking over that area. Then I will be back complaining about it....

Master Gardner
BrendaSue Solheim

Date: 02/10/2001 12:22 PM

From: Lorraine
North of Scotland
Hi from the north of Scotland. My pet hate is vinca, my neighbours garden is full of the hateful stuff and it persistently creeps through the fence and up the hedging. I am horrified when I see it for sale all over the place. Another hate is the dreaded hogweed, brought into the UK by a plant collector the thing is rife, it seeds everywhere and we cannot walk along the banks of burns and rivers in summer for fear of the stuff, the sap causes blisters.

Happy gardening year, Lorraine

Date: 5/12/99
From: Darlene Best
Plymouth, Indiana

Please warn people against the use of Crown Vetch - a perennial ground cover sold in all the garden catalogues.It is extremely invasive and chokes out the good plants. It spreads quickly (vine like) and throw seeds. Once its in , you can't get rid of it! Theres no stopping it! It is used on the roadsides - but trouble in a yard.

Date: 10/29 10:49 AM
From: Michael Blasi

Successful gardening in the claylike soil of central New Jersey (Zone 6) often requires a raised bed and lots of effort in soil preparation. Achillea 'Coronation Gold' (some call it yarrow) is by far my most troublesome perennial pest. Easy to fall in love with on a cold winter night as you peruse your spring catalogs sipping cafe vienna, this plant will start out looking very charming with beautifully detailed leaves formed into a perfect mound. You really start to like this plant! That's when the trouble begins. This achillea will slowly creep and then suddenly leap through the entire bed. Flowering begins in late summer on tall (4 ft), topheavy stems that soon require staking. Cutting back in mid-summer only makes things worse. It freely self-sows, so don't think that pulling out the main plant will end your relationship so easily....this plant will stalk you! If you decide to give it another chance, then treat it miserably.

Spoiling your yarrow only leads to divorce!


I have this Achillea in my back bed and it behaves itself wonderfully. I usually cut off the flowerheads before they actually drop seed because I don't like the fading color ... so I don't have volunteers.

There are other yarrows of the millefolium type that run a lot and I do have those spread. Also an Achillea clypeolata that will colonize, but it comes up easily. Just shows how difference in climate and soils can really affect a plant's behavior. I live in a cool summer area with sandy soil. -K.M.

Date: 10/16 8:42 PM
From: Lolellbe

Here in my Southern California garden I had the prettiest spring time plants with such lovely yellow flowers..My husband dug many of them up in a major clean up and I was so mad...But over the years this charming little "bulb" , I think, has spread into my more formal gardens and just won't go away. I am an avid eradicator now of the "OXALIS" DEMON..I see it advertised in bulb catalogs and want to warn any one who is thinking of letting this thing loose..THINK TWICE!!!!

I suspect that you are talking about Oxalis pes-caprae. It has become naturalized as a weed in parts of California, Australia, Mediterranean Europe and SW Europe, according to the Roger Phillips and Martyn Rix book, "Bulbs." Apparently, it produces little bulbils just below the surface of the soil.

Date: 05/17 6:22 PM
From: Rich, KilfDZines

I didn't think I had a perennial pest to contribute, but then I remembered... The first plants I ever bought mail order were in a grab bag from Michigan Bulb (go ahead and laugh). Included was something called hardy Ageratum (Eupatorium coelestinum). Long after everything else in the garden had bloomed, this thing decided it was going to bloom and it wasn't even that attractive. I decided to yank it up the following year, but it was too late. You see, it has creeping roots and it's still creeping to this day, 8 years later. It's easy to spot in the spring and I just pull it up with the other weeds.

Carpenter Perennial Gardens

Date: 06/03 7:36 AM
From: Catriona Ruthard

Dear Kathy
I have just found out the pest I hope I have gotten rid of. I hope it isn't anybody's favourite. The common name in these parts (Toronto, CA...Zone 5-6) is the Obedient Plant (Physostegia virginana). I think it is a plant that took its name too seriously. I found out it is a relative of the MINT family... enough said. I planted a small clump from my mum's next door neighbour. It went from that small clump to march across my perennial border taking no hostages. It wiped out everything in its path - even hostas. I took three weeks working on and off trying to get rid of it two years ago. It came back stronger than ever. It was the start of the demise of my perennial border. I just could not get rid of it. We have dug it out again. I hope it is gone for good. Oh, and I am not too happy with French Tarragon (Artemisia dracunculus) or Chinese Lantern (Physalis). I love the taste of tarragon and I have even made wreaths of the Chinese lanterns but enough is enough. My tarragon I grew from one small plant to a patch of 5 x 8 feet. It is all dug up and some of it is put in a pot for the kitchen. P. S. tarragon starts from root cuttings as well. I'll have to keep at it all summer pulling it out.

-Catriona- ;-)

Date: 06/10 7:41 PM
From: Dianne Duncan

The plant I can't get rid of (I also got from Michigan bulb), is Myosotis/Forget-Me-Not. I planted three plants (everything else I got from them died), this stuff took over my small garden that is limited because it's the only place that gets a lot of sun. I'm still pulling it out. It reseeds everywhere. My mother-in-law asked for some and I gave her some, but am afraid she will hate me for it in a year or two.

-Dianne Duncan-
Kingston, Washington, Zone 8

Date: 07/07 12:54 PM
From: Karen Johnson

I should add two items to the perennial pests list: They're not sneaks slipped in by Michigan Bulb Co., or a plant that looks lovely at the nursery then attacks your garden, choking out everything else. Just horsetail and scotch broom, which sneaks in with your soil, usually. I let horsetail get out of control in one garden, and had to dig the whole thing up and replace the soil to get rid of it. Of course the replacement soil also has horsetail roots, but I dig it out when I see it, and so far, so good. Same with the scotch broom, otherwise my garden would look like most of Washington State's highways....

Our zone is very close to being a Zone 7, because -- being on a plateau above the Stillaguamish and the Snohomish rivers -- it's just a tad colder than the Zone 8 in most of Western Washington.

Our soil type is sandy-loamy, originally. But I've had to ship in soil for the garden, which 1) was some sort of dense sandy-clay mix and had to be mixed with organic stuff to loosen and aerate it; 2) was from nearby fields, and was also sandy-loamy but with nasty scotch broom roots throughout (and they said it was sifted, too, made no difference); and 3) was a 3-way mix from the hills east of where I live (loam, peat, and aged manure), sifted also, but with a few horsetail roots in it. Sigh....

-Karen Johnson-
Karen's Pacific Northwest Garden Web Page

Date: 07/20 12:20 AM
From: Daphne Stannard

I'm in Tacoma, Washington, zone 8, with a variety of soil conditions.It doesn't seem to matter. Anchusa is taking over my garden and working its way up and down the alley to the neighbors. Sunset says, "Not for small spaces: once established it is difficult to eradicate." What an understatment! This plant can grow to be 5' tall. It has lovely bright blue flowers (like forget-me-nots) in the Spring and Summer (until the heat hits). It never suffers from pests or diseases and thrives with lots or little water, full sun or deepest shade. The problem is - a tap root often bigger than a parsnip which will grow even after being composted for a year! AND it self-seeds like crazy. It can't be pulled out unless the plant is just a seedling. Each and every plant has to be DUG out, the whole root, and thrown away! And the tap roots are very clever. If they grow next to a tree stump or under the edge of a large rock, you can never dig them out. If you don't get the whole tap root, it will send up new little leaves, pretending to be a seedling.Plus, the leaves and stems are covered in bristly hairs that are very unpleasant on bare skin. So handling them without gloves and long sleeves and pants is a no-no. I can't believe that anyone actually WANTS this stuff, even if the flowers ARE blue.


WE had a huge stand of this at my childhood home... near the edge of the woods and behind the garage... there it was lovely, but I would never want to walk in there! :-)

Date: 08/29 7:49 AM
From: Judy Fleck,

I believe it's Japanese Quince--(orange blooms - this is actually a woody deciduous shrub)... orange being my most unfavorite color of all, and I made the mistake of planting a small plant on both sides of driveway, and if I didn't prune it to the ground, my house would disappear!! Be wary.

-Judy Fleck-

This is not an invasive plant but a robust one. It underscores the need to research how big a plant might really get in your area before you plant it near walks or foundations. The tags are not always correct... might be good to look in other people's gardens and see if you can find the plant in an established yard. More telling than a tag.

Date: 08/08 9:34 AM
From: Mark and Kristin Shriner

I live in Nebraska, Zone 5. Here are just a few of the plants I have eagerly removed from my garden after finding that they wanted to take over.Oddly enough, most of these were given to me by experienced gardening relatives and friends when I was just learning about gardening. Hmm. Needless to say, I've learned a lot and now the first question I ask (if I don't already know the answer) is "how quickly does it spread and how." 1. Artemesia "Silver King", I see it's already been mentioned so I won't go into detail but to say that I agree.However, before I "launched" all of it out of the garden, I cut off a healthy bunch of it, hung it upside down to dry and then placed it in a nice vase.That was 5 years ago, and it still looks just as good. Guess you can't even get rid of it when it's really dead!! 2. Linaria, "Butter and Eggs". This one took over in the same manner as the Artemesia, except I still find it coming up every spring and I officially "removed" it 5 years ago. It gets about 3ft. tall and has small pale yellow, snap-dragon-like flowers. Grrr. 3.Vinca. You know, that dark-green creeping groundcover with those "cute" little purple flowers in spring. (sarcasm included here) I have my own little landscaping business and once dealt with about a 30 X 30ft. "crop" of this stuff all interplanted with MINT!!! After 2 years of trying to battle it's unending root system, I told the folks to have it sprayed.Well, that helped, but it's still growing. Grr. again. 4. "Snow on the Mountain", variegated pale green and white leaves.Nice looking plant, if you like to look at a lot of it! 5. Ribbon Grass, I've found that if you plant this one in the shade, it's not nearly as spreading. 6. Violets. Etc. Etc. Etc. Please, anyone reading this who would like to have a nice, organized, clean looking garden, do not use any of the plants listed above, or be warned.

Good Luck!

Get more out of life-- Drink Coffee

Kathy says... live a healthier life... drink water! What can I say?... I'm LDS! ;-) Thanks for the humorous input... you might have saved someone your pain!

This page last updated 15 August 2007.

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