Sunday, July 6, 2008

Too much of a good thing is never enough.

That's what my refrigerator magnet tells me. And when you're trying to combat acres of hurricane-produced weeds, you can develop a different attitude toward "invasive" plants--I prefer to think of them as "prolific." Still, finding the right spot for aggressive growers can be hard, particularly when you don't realize quite how much a certain plant will like (or love) certain growing conditions.

As I work on the front of the house, I'm faced with ferns, houttuynia and crocosmia run amok. The ferns are natives, and I haven't been able to identify them--they're deciduous, they're about 24" high and very upright, and their roots form dense mats that choke out other plants. They thrive in the bad soil under the French drains at the very base of the house, and they attract Japanese beetles.

Above are some full grown ferns growing behind a hydrangea (they're usually more upright, but we had some much-needed rain last night); below are shots of the root mass and of some babies growing back where I pulled them out of the drain two weeks ago.

I love ferns, and these are pretty in the right spot--they provide a nice backdrop in the tropical garden, for example, and the fig tree there can stand up to them. But the front border is too small for them, so I'm moving those to parts of the property that we don't plan to cultivate, so they can help combat the weeds that sprang up when the big trees fell. Anyway, does anyone recognize this fern?

The houttuynia--well, it's made Dave's Garden's list of top ten thugs (#4), and I wish maybe I'd checked with Dave before I planted it where I did! I'd never heard of it when I bought it in a very reputable local nursery a few years ago. I was looking for a little groundcover, and there was this colorful little plant looking like a cross between coleus and ivy. Nothing on the label suggested it might have a supporting role in Little Shop of Horrors. I bought three four-inch pots (cue the Gilligan's Island theme song: "three four-inch pots . . .")

Truthfully, I have a love-hate relationship with the stuff. I've just let it go around the loropetalum by the back deck, and I like the effect. This is my crazy border--the houttuynia competes happily with marjoram and chrysanthemum (the latter from a house warming gift in 2000--it's now all over the yard), and the loropetalum is itself a kind of freak--it was supposed to grow to about six feet, and it's easily ten and still growing. Bearded iris actually fare well in this bed--the other plants die back in the winter, so they're still small when the iris bloom--and their chaotic midsummer sprawl covers up the aging iris foliage.

I also think houttuynia is pretty in pots--it sets off petunias nicely, and deer don't like it so it tends to protect the tastier annuals.

But it's hard to get rid of it when you (well, when I) plant it in the wrong place--and the front bed where I started it was the wrong place. It's one of the few plants that I won't try to find another spot for when I pull it up--it transplants very easily, so if and when I ever want it in another spot, I have a permanent supply.

Crocosmia, on the other hand, isn't typically considered a thug. Mine isn't quite in bloom yet, but in week or so, the gardens will be full of deep red-orange flowers suspended on slender upright stems--from a distance, the flowers almost seem to float above the sword-like foliage. I think mine is a "Lucifer" cultivar, but I'm not sure since it came from a friend. I love the plant--and the plant loves my soil conditions. It grows from corms, but it also seems to spread from its root system--the handful of corms I started with has become literally hundreds of plants. Crocosmia isn't a problem the way other invasive plants can be, because it roots close to the surface, seems to happily coexist with whatever it works itself into the middle of, and is very easy to pull out and move somewhere else. Nevertheless, the tall, strappy leaves can obscure other plants: this stand started out two years ago as maybe ten corms that I envisioned as a small clump at the base of a crape myrtle.

During the spring and summer, the large clumps accent the corners of the house and garden very nicely, especially when the plant is in flower.

But the straps are fairly unsightly by autumn, so I've been transplanting to the back of borders and among autumn bloomers like mums to hide the wilted foliage.

So I'm removing these prolific plants from the front to allow some more gentle ones to fill in. I'll end with a favorite one, also comfortable at the base of the house, also easily transplanted, but much more polite around other plants.

This is sarcocca hookeriana, and it's a good thing I'll never have too much of. It's held its own beneath the ferns and crocosmia, and provided a nicely spreading bed that I am planting among the barberry and box at the front of the house. It's an evergreen with small, white, fragrant flowers in winter and early spring, and it will gradually provide a beautiful groundcover around the shrubs in the front.

Time to garden so that I'll have something else to write about--until next time.


Roses and Lilacs said...

Good morning. I agree, invasive plants have their place. Even the dread bishops weed looks very nice surrounding a tree or shrub with a lot of grass (and a lawnmower) keeping it in check.

I had my battle with houttuynia a few years ago. It took a couple years to completely remove it from my bed of hostas. It is a pretty plant. I now grow it in a pot.

tina said...

Oh boy-the little shop of horrors. The first owner of my house planted it out front-urrrr! I've been trying to get rid of houtenyia for four years now. No luck. Roundup doesn't do it, digging doesn't work. It still comes back.

I was at a friend's house yesterday and she was telling me how she loved her vinca she planted out front. She also had a red tinged plant she was going to plant there. My heart sunk as I knew it was houtenyia even before she proudly showed it to me. I warned her! Now she will have no one to blame but herself if she plants it. The rest of us, sigh...

Cosmo said...

Hi, Marnie and Tina--I hope you both spent some time in your gardens over the holidays. We finally had some rain, so I spent a couple of cool mornings weeding and pruning--my kind of morning.

Those ferns are actually more of a problem for me than the houttuynia, because they choke plants around them (except things like houttuynia)--so I hope I can get them attacking the weeds under the trees! Happy July, and thanks for your comments.

Gail said...

I am with you, I have several invasive plants that have overwhelmed me and I have cried uncle! Both Vincas were here when I moved in and they are impossible to eradicate. Now I mow it down and pull it out but I think it will be with me forever!

My neighbor refused my offer of columbine seeds saying they were too invasive. As I looked at her beds I noticed she had planted Vinca minor everywhere...I had to bite my tongue!

Just for the heck of it I looked up Ferns + site had two pages listed!

You must have fabulous soil!


Les, Zone 8a said...

I also have your two thugs. However, my houttuynia is not a problem. I have it around the pond in a fair amount of shade and it seems to stay put. In the late winter the same area is amok with lesser celandine. My corcosmia is definate weed, although easy to pull and it makes a good cut flower.

...and yes wasn't the rain wonderful and needed. We spent the fourth on the Eastern Shore and came home to puddles. What a great site. Now if we can only get relief from the smoke.

Cosmo said...

Hi, Gail and Les. I don't think we have great soil in the Tidewater area--it's very clayey. I used to double dig when I first started; now I usually just dig out the clay and replace it with a mix of compost and topsoil. Those ferns grow in unamended soil--it's kind of amazing (it's soil I have to break up with a digging bar!)

So we're finally getting rain where we are--Les and I have been living with smoke from the fires in the Dismal Swamp in North Carolina, but we got about 4 inches of rain last night, which may have helped dampen the fire--no smoke smell here this morning.

Randy and Jamie said...

I've just recently developed an affection for crocosmia so I'm going to start a collection of them. Since I'm not a patient gardener it's wonderful that they spread so fast. If I get too many of them, then I will just have plenty to share. Your blog is wonderful, I look forward to being a regular reader. :-)

susan harris said...

Hi from GardenRant's Susan (also SustainableGardeningBlog). Of course I had to rush over here to see where you are - Tidewater, huh? I used to vacation at Buckroe Beach until a hurricane demolished the family cottage. After that, it was Nag's Head every year. I grew up in Richmond, btw, now live in Maryland, a suburb of DC. Thanks for stopping by and welcome to the gardenblogosphere. Susan