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Wednesday, March 19, 2008

Vigorous, Aggressive or Invasive?

One of the tips I gave while lecturing is to try to read between the lines when reading that tag in the pot at the nursery. The advertising world is a savvy one and many descriptions are phrased to make something that's not very desirable look perfectly normal or even an asset.

Two phrases get me hot under the collar. The first is when the tag says "short lived perennial". Reading between the lines, that usually means the plant is a biennial. Why not just say "will die right after blooming". I have many biennials that I grow and adore but at least I know they're supposed to only live two years and I don't fret and wonder what I did wrong that killed the poor thing.

The second phrase that drives me crazy is "vigorous grower". When you see this phrase it usually means "start running after you've planted me in the ground if you don't want me to bury you alive". So often I'll be shopping at a plant center and see people pick the pot that's busting out of it's seams. "Look Honey, this one even has some pieces growing out of the drainage holes, what a great bargain!". I want to tap them on the shoulder and say "start running now".

Being realistic, when does a plant cross the line of vigorous to aggressive or worst of all, invasive? I don't care about whether it's a native plant or an import, invasive means invasive. It means that the plant will run over, through, or under all neighboring plant material. In a few cases it might be the seedlings that self sow in the middle of other plant material but most often it's the underground thugs that I've got a problem with.

Lysimachia ciliata 'Firecracker' is the number one thug in my garden today. I can only blame myself for this one. A good gardening friend shared a piece with me and warned me that it runs. I fell so in love with the rich purple foliage that I begged more pieces from her.

The above two photos are two viewpoints of one planting area. The first shows you how lovely the purple foliage contrasted with the neighboring plants. The second photo shows you more of the surrounding area, the Lysimachia still fairly well clumped with a few stray pieces off to the left.

When removing leaves from this area in the last few days I'm horrified to see that the Lysimachia is everywhere, choking out the daylily clumps like they were butter. The Nepeta 'Six Hills Giant' and Euphorbia are still holding ground but for how long?

The little blue ground cover here, Mazus reptans can run as far and as fast as the Lysimachia ciliata. The big difference is the Mazus doesn't choke the companion plants. It simply grows around them and fills in any open spots. If it goes where I don't want it, the roots are extremely shallow and I can remove any unwanted plants in a few minutes.

Here in this golden yellow display are several vigorous growers. Coreopsis 'Zagreb' is the strongest growing Coreopsis in my garden. I choose it over other varieties because it never flops, the stems nice and strong. While it might not grow through a daylily clump, it spreads at a good rate and every 4 years or so I need to go in and pull back the outer edges.

The large leaves in this photo are from the perennial Begonia, I don't have a better name as it was a pass along plant. I'm not sure it's as perennial as people tell me, it just might be a good seeding annual but it has never sown too many plants for me. Further up in the photo though is the adorable blooms of Corydalis. While I'm crazy about this plant, I really need to get in there and be ruthless with some of those seedlings. At least they are easy to pull out.

Uh oh, do you see what I see? There's that tiny spot of purple in the left hand margin. Guess what's run over, through and under everything in this area now?

While most Sedums are well behaved, there are a few that are vigorous growers and yes, some are invasive. This photo shows Sedum aizoon 'Lemon Snowflakes'. It's not invasive but I would list it as vigorous. The original clump grows at a nice pace but it sneaks out seedlings that pop up in the general vicinity. Thankfully it is so pretty and so few people grow it that I've found homes for all those seedlings.

The very first Nepeta I ever bought was at a local nursery named Franks. I didn't know anything about cat mints, didn't save the tag either but the name Nepeta mussinnii keeps popping up in my head. This plant seeds around all over but never choked out another plant. Best of all, I've put many of it's babies in large planters and they over winter just fine. They have such a long bloom season and look so lovely cascading about that I still wish I had more of them.

If you look carefully though you will also see the foliage of Violets in this bed. They are a bit harder to deal with and would have to be moved up the list at least to "agressive" and I know other people who would call them "invasive". It took a bit of practice but now when I weed this area I use a dandelion fork and pop out any violets that are in the middle of the dwarf Hosta.

Symphytum (comfrey) was on my wish list for years. The only variety I've found for sale is this pink one, 'Langham's Pink'. While I was highly warned by others, I bought five pots of this plant. Contrary to all advice, four years later they are still in clumps, not a runner or seedling to be found. I'd really like to try to divide these beauties up in a few weeks.

When it comes to finding out what plants are vigorous, aggressive or invasive, blogging just might be the best available tool. While there are plenty of great gardening books out there with this information, it might take you hours or days to find what you need to know. By going to the search tool at Blotanical, you can simply type in a plant name and instantly read about how it does in other gardens. Pretty cool! If only I had thought of that before I twisted Chris's arm for more Lysimachia...

And now for the most distasteful task of all, time to empty the hearth and fireplace of all winter decorations. Other people might call those decorations "Christmas" decorations but thankfully we call them "winter" decorations so we can leave them up all winter. For the past month I've been averting my eyes every time I walk through the living room. It's a much hated job since it requires numerous trips up and down the attic stairs while loaded down with boxes. That's my ugly confession for the day.


Dave said...

You have such a huge collection of plants! i like the catmint. Once mine gets established I'll start taking cuttings of it. There should be a universal system for invasive plants. Maybe a big "I" should be on each tag but then I guess they wouldn't sell! Maybe a ratings system similar to the movie rating system would be good. It might be better than having to read through the creative lingo. Of course a lot of people go and don't look at that aspect and get stuck with an agressive-invasive plant. Good post!

Nancy J. Bond said...

As one who is still planning her perennial garden, this was a very informative article! Thanks.

Blue Fox said...

So much depends on your particular conditions - the soil type and winter cold and all that. My biggest thug is a beautiful golden lamium - it's a spreader and it self seeds, but the babies are green! I think it would still escape even in a pot. I never learn, it's a mint relative!

Frances, said...

HA, I thought that lysimachia firecracker sounded so pretty and it has been a thug. The foliage is a wonderful shade and maybe if the only thing we were trying to grow was trees and large shrubs it would make a fine groundcover. It is constantly being pulled and will eventually be brought under control, but we should have been warned. When I asked the nursery owner where it was purchased what to do, she said to spray round up on it!
Frances at Faire Garden

Anonymous said...

A really good post! I enjoy the fact that you pair pictures with your posts. It's great for someone like me who is not really all that familiar with perennials.

As for your dandelion fork, I had to do a Google search on that one. I have that tool, but never knew it had a specific name. My favorite weeding tool is something called an EZ Digger which is currently sold by A.M. Leonard. I bought mine years ago and I am not sure who I ordered it from. At that time, it was called something more exotic and had an oriental name. All I know is that I can't weed without it.

That might be an idea for a post someday--garden tools you know and love.

Whatever you write about, keep it up. I learn something new every day.

Sorry, Melanie, I guess I have to be anonymous today. It refuses to accept my password.

Gail said...


Universal clothing sizes and universal plant tags, I am all for them.

L quadrifolia/whorled loosestrife showed up in my garden and seeded in between the bricks, etc.

I love the dandelion fork, I had one with a long handle and as the weeds popped out, Tilly, my cat would leap in the air after them.


Katarina i Kullavik said...

Thanks for visiting my blog - I'm so glad I found yours! Your last post is very interesting and useful. I will take your advice in future and read the labels more carefully.
/Katarina (Roses and stuff)

Anna of RavenCroft said...

Speaking of winter decorations, my neighbor has hung out their very cute Happy Easter banner, which looks really stupid next to the wooden candy canes & snowmen they have yet to remove from their front yard. Ah, only in America LOL! SO you see Melanie, you are not alone.

GardenJoy4Me said...

Melanie .. I can't believe you and I did the same trick with Firecracker .. mine went right under a wooden fence and through my neighbor's brick patio .. I still have a few in a specific place and keep an eye on it .. Call me a fool for loving that dark foliage and bright little yellow flowers !
I have had a few comments on my white Gooseneck Loosestrife .. but it is in a "tough conditions" place .. I don't mind if it does a bit of colonizing .. for now ?

Brenda Kula said...

I haven't had any luck with catmint, but have some seeds to sow right now. People tell me mint is invasive. But my gardens are only a few years old. Haven't had that problem yet. Mine is planted around the pond. Makes it smell good. Seems to me you're doing a lot right to get that much stuff going in your gardens!

Cinj said...

My biggest thugs in my other garden were the dragon's blood sedum, yarrow, and staghorn sumac. Some plants like to crowd everything else out of the yard. YIKES!

Robin's Nesting Place said...

Another winning post!

I find that yarrow is too invasive and hate trying to keep it pulled from the garden.

Anna said...

Alright-I got my Old Country Gardens Fix for the day--I can live another now. I run from anything that has lysimachia in the name. It is tough as nails. I thought I got rid of mine but just this week--saw some creeping up. The new owners are going to love me for it.

Loved your warning for those seeking plants that have roots growing out the bottom of the pot!!! Too funny.

Melanie said...

Dave, I really do have a huge collection but every year I find more that I just must have! Right now I have 5 or 6 different catmints but my favorite was a pink blooming one 'Dawn to dusk' and I need to get it again. I had to move it when I had the tours here and didn't get it back in the ground soon enough.

Nancy, I'm glad it was helpful, I always try to think of things that I wish I knew before I made all these mistakes.

Blue fox, you are so right! So many of the things I'm reading here that are thugs for other people are fine for me and viceversa.

Francis, at least I can feel better than I wasn't the only sucker. I still love the way it looks, it'll probably stop me from pulling every single piece but I do promise to be ruthless.

Pauline, I have problems with the password thing all the time. I have to click on the circle that says Name/URL and fill that out instead.
I like the idea of a tools post.

Gail, you made me laugh out loud at the image of your cat leaping!

Hi Katerina, I will have to remember to listen to my own advice too! Today I didn't read the tag because I forgot to bring my glasses. I just started wearing them and it's so frustrating when I'm in a store and can't read something.

Anna, what a picture! The whole wall of my living room is granite with a massive hearth. I cover it with winter greens, twigs with cool bark, pine cones, dried artichokes, and lots and lots of elves (I have a thing for elves). It really isn't "christmas" but kind of looks like that. I'm glad I finally got it all cleaned up and even did all the vacuuming afterwards. My back will pay though for all those trips up the attic ladder.

Joy, you too! Last year I potted up some of the lysimachia 'Firecracker' in plastic planters and put them near the street. Two years ago I was hit by Hosta thieves who stole my whole new row of expensive Hosta. I was hoping they'd come back and steal the Lysimachia but no go...guess they aren't as dumb as I thought.

Brenda, no problem here with any of the catmints but I have acidic soil, don't know if that's why.

Cinj, and Robin, you both mentioned yarrow and I've lost it every year for 3 years now. I always blamed it on our cold wet springs but now I wonder if it's our acidic soil. Maybe it likes alkaline soil instead?

Anna, you are so funny, glad I could help fuel your daily fix :-) My mom called the other day because I didn't post early enough and she needed a fix with her cup of coffee.

(Hi Mom! Love you!!!)

Cabs said...

If it makes you feel any better, we just loaded all our "winter" decorations back into the attic (up a ladder) on Sunday. I have declared it Spring!

Thx for your comment on Terra Nova Design. Glad you like my "new look."

I am headed your way tomorrow, NYC actually.

garden girl said...

I have my moments when I'm tempted to bring home some lysimachia or some other invasive species just to get something to stay alive in my dry shade!

Not really. I've made my share of mistakes with vigorous spreaders and self seeders, and don't want to go there again if I can avoid it. Trying to eradicate a mistake like that can take a long time, and just when you think it's finally gone, it pops up again someplace else!

Meems said...

While I can't relate to the same plants you are able to cultivate I can relate to the subject at hand. I happened to be talking to someone about this just yesterday. Even the online retailers don't give out information on plants that is (IMO) 100% correct. Of course they want to sell plants. That is why it is so important to do the research.

Always enjoy a journey through your photos. So pretty and so nicely done.
Meems @ Hoe&Shovel

Layanee said...

Don't you love that Euphorbia!? I don't have that Lysimachia but I do have the gooseneck and it is invasive but easy to pull. The funny think is that it is invasive only in the one garden! In the dry garden it is well behaved!

Hoot Owl Hollow Nursery said...

Short lived perennials aren's all biennials. Some things are truly perennial, but I expect that there preferred location is in a different, colder or warmer zone. We have lots of things that make it 4 or 5 years here and then I replace them because I like them so much. Sedum Aizoon is not so well behaved here. I also got it because it is so pretty, but it spread about 4 feet in all directions before I pulled it all out and now I still find seedlings 20 or 25 feet from the original clump. If you want a really knockout comfrey, try one of the variegated leaf forms. We have 2 of them. Not quite as hardy maybe but definitely not invasive.

Mr. McGregor's Daughter said...

Great post! I'm always on the lookout for buzz words such as "vigorous," "excellent groundcover for dry shade," and my favorite "spreads by underground runners." I'm in the midst of an experiment to see if I can restrain Convallaria majalis. The former owners planted it, but it has started to become invasive. I love the flowers so much, that I don't want to get rid of it completely. Hence my experiment of planting it in sunken containers in the garden. It'll be interesting to see if the runners sneak over the edge, or if the roots will break the bottom of the containers first.

Kathryn/ said...

My current home came fully stocked with the most aggressive plant I have ever had to deal with: arum italicum. Stand forewarned. It is EVERYWHERE. It is taking over every single part of this large property. I have to routinely just pull it up, pull it up, pull it up.
Did I mention is it poisonous as well? Oxalic acid. You don't want to hear about my vet bill Finding This Out
the Hard Way. The mere mention of the word "corm"
sends me out the door...

Dee/reddirtramblings said...

I can see why you loved that little purple flower. It is pretty, but I'm sorry it tries to take over every year. coreopsis zagreb doesn't reseed or spread here. All of the fine-leaved coreopsis just barely make it while the broad leaved ones seem to spread a little more. The only thing I'm worried about right now is Mexican feather grass. We made some new beds last year and put manure mix soil in them. My MFG had only been in regular soil. It took to the new manure mix like gangbusters, and I've been pulling it up everywhere.~~Dee

Cinj said...

If you want to go with yarrow, I'd put it in a pot and keep it reigned in! It is beautiful, but spreads like wildfire. I think it does like alkaline soil. My new soil is acidic. Hmm, maybe I should try an experiment for you??? Hubby would probably kill me if it made it over here though. He views it as a weed!

Melanie said...

cabs, I feel much better knowing other people were as late as me with my winter decorations.

garden girl, can you believe I willing planted another piece of this insane lysimachia in the dry shade around my mail box! It's a spot that gets hit with road sand and crap and the garbage men always throw the garbage can lid there. Hope I'm not sorry soon.

Meems, you are right, selling seems to come first, information comes second.

layanee, I have the gooseneck loosestrife too, I love it, invasive or not.

Hi Jane, you really are right about the biennials, for instance, Verbascum was short lived but not a biennial for me. I only saw the variegated comfrey once and it died on me, if I see it again I'll try it again in a different location.

mr. mcgregors daughter, last year for the first time I potted up four pots of convallaria and people complained that I didn't pot up more. Bwa ha ha, this year I'll make sure I have plenty :-)

Kathryn, how funny, I'd give anything to get some increase from my Arum italicum! That's the big difference between the east coast and the west coast I guess. Dee, the coreopsis 'Zagreb' doesn't seed here, it just grows in every direction. If I move a clump it always seems like a tiny piece left behind starts growing all over again. Doesn't matter though, I love this plant and have many large clumps of it.

Cinj, yarrow is another one I've been struggling to keep alive. Can't figure it out at all, I never had a problem in the past. Maybe it's the new cultivars I'm trying and I need to get back to some of the earlier varieties like "Paprika"