I should amend my own post to say that it doesn't necessarily have to be something that would run rampant, just any kind of plant that could hold its own, or even spread, against weeds.

Ornamental grasses are really popular right now. There are so many colors and heights available from greenish blue to blood red, redish black to soft pink, and they generally are not rampant. They are very thick at the base so that weeds will not get a foothold in them.

tansy,

Great idea! I have thought of the same thing in the past. You do have to be careful though, some ornamental grasses are annuals in certain zones.

farfaraway,

How about daylilies? I am sure you can find someone in your are you can trade with that has them, in exchange for some of those fine plants you winter sowed!

Hostas for the shady areas.

Daylilies are a great idea. They blend well in the gardens.

Tiffy,

Hosta is another good one!

I planted maybe a half a dozen different daylilies in mom's yard a few years back. The amount of additional plants that we got from them just spreading is astronomical. They do spread, but are easily transplated.

I am trying to find room in my yard for them.

How thuggish?

For foliage, look at some of the mints, some varigated, crinkle leaved but they can get out of control and you will NEVER be rid of them

look at spiderwort - spreads via roots as well. The flower is pretty - white, pink, purple. slightly less out of control than the mint. can be cut back or deadheaded and will rebloom

On a less rampant note, I have Artemisia 'Oriental Limelight' - very pretty grey-yellow-green varigated foliage - can also be cut back if it gets too tall. Again spreads by root, but much easier to remove where you don't want it. :-)

Linda

oooh, I love the idea of artemesia. I am starting some of that this year, but isn't it kind of delicate and ferny?

I also thought of sweet woodruff. It could be said to be rampant, BUT it so easy to pull up, it doesn't really ever become a problem. It blocks weeds well and fills in shady and dry corners too.
It gets a nice white flower in the spring, breezes through winter with no problem, has a woody stem and sort of umbrella like leaf form which are delicate in size. Mostly disappears in winter but comes back thick and lush well ahead of the weeds usually.

Another great ground cover is plumbago. It gets a beautiful blue flower from late summer till frost, has tough foliage that comes back every year with tinges of red, does not let weeds spread. Has a mind of its own.

Grown around the Washington Cathedral in places. A great plant with great color.

Those two more I'd recommend as beautiful thugs: plumbago and sweet woodruff.

I'd watch out for those mints. They might be worse than what you are trying to get rid of!

It is true, though, that beauty is in the eye of the beholder. Everyone likes different things. I have given away many perennials, eliminating them completely, because they spread so much. Spiderwort was one of those, also perennial geranium, considering adding verbena bonariensis to that list. Sometimes the cure is worse than the disease.

Karen

My vote for "prettiest thug" would go to Gooseneck Loosestrife. Actually a plant I loved until it ate half a bed! Pretty white flowers (shaped like flowers on a butterfly bush, but smaller, nice, neat foliage. But if you plant it you will never ever get rid of it, runners go throughout the bed quickly. A friend who has it in a small contained bed loves it,uses the flowers in cut flower arangements too, but I felt it was taking over and struggled to get it out for two years.

How about something like black eyed susans and/or purple coneflower? They spread like crazy and yet are not all that difficult to get OUT of the bed if you change your mind later. And you just might; you never know...

Nancy

A few more:

Any type of yarrow.
Astilbe, given the right conditions.
Beebalm.

WOW, everyone, thanks! What a wonderful list of suggestions!

Tansy, I love your suggestions of ornamental grasses and sweet woodruff. And plumbago...never heard of it, must check it out!

Linda, my property is already covered in mint...no more mint! Ha ha...I will look into your artemisia suggestion. I've heard of the plant before but have no idea what it is. Sounds intriguing!

Nancy, I like the coneflower/rudbeckia suggestion; I can think of one bed where they'd be perfect because it's hot, sunny and dry.

Tiffy, I guess I've overlooked daylilies; I need to check into them. We have them all over our property, but I think they've gone "blind" like some of our daffodils and are no longer blooming. They probably need to be divided.

Greengardener, I love bee balm AND astilbe both. Not so fond of yarrow, though. Astilbe would be really pretty in one of my shaded areas.

Thanks to anyone else who replied...I've recorded all your suggestions into a nice list so that I can get started on some of these beds. We've lived here 4 years and it's been overwhelming--we have at least 1 acre absolutely filled with flower beds, and I've been chipping away at them all this time. I'd love to make a little more progress with some plants that can hold their own against weeds!

Far,
You also have to consider that what is a thug to one might not be to you. Any plant you introduce such as Gooseneck Loosestife or Verbena Bonariensis should be closely watched for about three years as per their nature to take over.

Unlike Karen's Verbena, mine reseeds politely in a USDA 5 and the footing grows slowly and with grace. It also attracts White Admiral Butterflies which are gorgeous.

The Gooseneck Loosestrife also spreads slowly here and caters to butterflies as well.

Yet today I am removing a real thug out of one garden. It is beginning to choke Ribbon Grass of all things after being in the same confined bed for three years. It is Lysimachia Ciliata Firecracker. You should see the roots on this thing!!! UGH!

How about Obedient plant? (Physostegia virginiana) It has really pretty flowers and is an aggressive spreader. I bought a pretty pink cultivar from Bluestone Perennials last Spring and it's already spread nicely from last year. I planted it in a dry and sandy spot which it doesn't prefer, to help keep it under control.

Terrene,

Thanks for the heads up! I just purchased some Obedient Plant seeds from the dollar store. I remembered hearing the name and couldn't remember if people had called it that because it was "obedient" or just a rascal.

How aggressive would you say it is? Very or somewhat more than an average perrenial?

Someone posted about Obedient Plant problems within the last week or two, you should be able to find the thread and read all about her troubles! I have sandy, poor soil, and in dappled sun it spreads medium to medium-fast. I'm beginning to wonder if I like it enough to keep fighting it back. I do like pretty thugs, but I think I like Obedient Plant more in the really bad spots, like the dead, dry shade where it will still bloom.

Tiffy, I acquired both that Lysimachia Firecracker and Ribbon Grass in a plant swap last year. The ribbon grass doubled in size in a month! I dug it up, potted it, and sunk the pot. I kept the Lysimachia in a container for much of the summer, and it's planted in almost full shade now. Should I worry about it in full shade and pretty decent sandy soil? If you're finding that it's beating back the ribbon grass, I'm scared!

Oh, and I wanted to mention that I think the Plumbago mentioned above is Leadwort, or False Plumbago. Real Plumbago is hardy in the south, but not zone 5. A neighbor has Leadwort as a groundcover, and it's beautiful.

Greengardener, apparently it's called Obedient plant because you can move the flowers to odd positions and they will stay there? Not because it is obedient and stays put! Mine didn't flower much last year, being a 1 year old perennial. There is a cultivar called "Miss Manners" which is supposed to be less aggressive though.

It is rhizomatous, and looks like it has sent out new clumps this year. I will keep an eye on it, and if it's too aggressive will probably move it to a dry, sandy and SHADY spot. Nice to have stuff that will grow under such conditions though!

Tiffy, you make an excellent point!

I planted two nursery verbena bonariensis last year and I loved them...and I only got two volunteers. They grew right through the weed cloth in my front bed. I moved them last week and they're already doing well; the butterflies and bees flocked to those plants last summer!

I did WS a flat of VB for this year and I didn't even think that it might be a good plant to put in one of those beds. Thanks!

Stage Rat,

The Lysimachia F. actually started growing within the Ribbon Grass. This is a dry spot surrounded by huge boulders which in turn heat up with the sun and create a spot that is very difficult to garden in. Here's a picture from last year... The Lysi is in full bloom (yellow) and the Ribbon Grass is on the left. You will also note the Gooseneck Loosestrife in front which does well.

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I have removed a lot of it but would still like to keep some in that garden. It is a pretty plant - especially from spring to mid-summer when the leaves are burgundy. Definitely keep an eye on it. It was starting to make it's way into an adjacent garden. The roots were creeping under one of those boulders.

Pssst... Your foxgloves started to germinate today. :)

Green,
Terrene is right about the Obedient (Physotegia) plant and the reason it is named that way. It's definitely not because of it's nature.

I had the mauve coloured one and removed it last year. In one year it was starting to wander impolitely into other gardening areas too quickly.

I winter sowed the white version this year. Apparently it is more tame. Notice that I used the word 'apparently'. :O) I am also clearing a small meadow where there will be much more space for it to wander in!