Wednesday, 13 July 2011

Houttuynia Cordata Chameleon (13 JUL 2011)

There are a few plants in my garden which I would describe as sinister. Houttuynia Cordata Chameleon is one of them. I didn't realise this until I saw what I thought was one of my weeds in another blogger's post. Alarm bells started ringing. Until that day, when I discovered its name and started researching it, I wouldn't have believed that it was a desirable garden or pond plant, which can be bought in nurseries or ordered on-line, cheap as chips.

If you asked me to define a sinister plant, I wouldn't be able to tell you, it's just a gut feeling, like when you're walking down a street on a dark night and you spy a person in the distance who prompts you to cross over to the other side for no explicable reason. Invasiveness is probably a key factor with sinister plants, but wisteria is invasive and I don't find it sinister, I admire the way it challenges me in fact. Maybe it's underground invasiveness that I have a problem with because you can't see what it's up to. Slugs avoiding certain plants also stirs suspicion, but I found at least one specimen of houttuynia that's been chewed by something, which is slightly comforting.

If you snap a leaf apart, a zest of coriander scent hits your nose. I don't recommend eating it, but the species form of this ornamental hybrid is eaten in Vietnam as salad leaves, where its name translates to fishy mint; its roots are stir-fried like bean sprouts. It's also used in Chinese medicine, even reported to have helped cure the SARS epidemic. On the other hand, it's listed in the global invasive plants database and I've found several comments on the web from gardeners saying this plant should be sold with a warning, including a husband accusing his wife of creating an ecological disaster in their garden by planting it.

I can understand why people might be tempted to buy my chameleon variant as an attractive, ground-cover plant. The red pigment in the leaves is brought out by sunshine on more exposed parts of the plant, whereas leaves protected by the bordering wall or other plants are just green and yellow like ivy.
 
houttuynia in the sun
houttuynia in the shade

So far I have just been pulling them out when they get in my way, not digging too far down and disturbing the roots; I assumed that was why they kept returning. For the purpose of this post, I pulled out the tallest stem to see if I could photograph the network of roots underneath. This wasn't so easy to do without washing off the soil, but here are the different thicknesses of root I found on digging deeper and deeper. Then I read that, according to  Paghat, just a small fragment of the thick root can be used to propogate this plant; by breaking it off, I have probably inadvertently induced it to have a reproductive spurt!

tallest houttuynia
houttuynia roots

Apart from this photo of a matted network of houttuynia roots, I can't find any evidence on the web which shows exactly how invasive this plant is. It's supposed to thrive in damp soil, especially at the edges of ponds or even submerged in water, though it can adapt to living in drought conditions too (rather sinister don't you think?). In my garden, I noticed it in a flower bed a year ago, in half a flower bed to be more accurate, which I only water at the bases of annuals when they start wilting in the height of summer. There aren't any annuals except for self-seeded marigolds in my garden at the moment, so it's a good time to show the aforementioned flower bed to you - here are two views up and down the bed.

 
At first you may not detect the houttuynia, but once your eyes get accustomed to the leaves, you see them pop up here and there. It certainly has a presence, but I wouldn't say that it has invaded completely yet. Only time will tell if the plant remains contained in this portion of the flower bed becoming more dense, or if it travels up the bed eventually covering the other half too. My gut feeling is that if I don't over-water this area, it will just fill in the spaces between the other plants. What's going on underground is another matter; sometimes it's best not to probe too much.

accompanying a baby rose
 
accompanying a bulb
  
accompanying a baby lupin
           






accompanying a marigold

accompanying a hebe


houttuynia doing their own thing
 














The jury is out on the scent of houttuynia, reports vary from coriander to tangerines to raw fish :
http://www.uni-graz.at/~katzer/engl/Hout_cor.html
http://www.pfaf.org/user/plant.aspx?latinname=Houttuynia+cordata

Species houttuynia roots stir-fried like bean sprouts in China :
http://www.geolocation.ws/v/W/4cc0e32c1d41c8067f0112f8/roots-of-the-plant-houttuynia-cordata/en

This blogger eats the leaves of the species form of houttuynia before it bites back :http://nashvilleveggiegarden.blogspot.com/2008/07/my-favorite-herb-houttuynia-cordata.html

How to save your garden from houttuynia attack :
http://www.pittsburghlive.com/x/pittsburghtrib/lifestyles/homegarden/s_745325.html

Houttuynia is included in the global invasive species database :

©Copyright 2011 b-a-g. All rights reserved. Content created by b-a-g for  http://experiments-with-plants.blogspot.com/2011/07/houttuynia-chameleon-13-jul-2011.html

15 comments:

Esther Montgomery said...

I'm sad it's sinister because it looks interesting. I know what you mean though about some plants bringing out revulsion and suspicion. There are even some which I accuse of being dangerous and poisonous - even though I have no idea whether they are or they aren't. They just look it.

Esther

gardenwalkgardentalk.com said...

Oh do I agree, sinister. I have a client that planted it long ago and has been trying to eradicate it ever since. I almost fainted when I saw how it was taking over everywhere. You are right, it needs a warning label.

debsgarden said...

My houttuynia is planted in dry shade, far from a water faucet. I imagined a mass of it covering the ground in a particular part of the woodland garden. It barely survives. I think with better conditions It should be planted where it can be contained or where it can have free reign to ramble as it wishes, without interfering with other plants, for example - an island bed surrounded by asphalt! I plan to transplant some of mine to a pot and place it in a sunny spot where I can enjoy it but it will be no threat to other plants.

Kalipso said...

I too have Houttuynia and manage to keep it under control. Invasive - yes but looks nice too.

Cathy and Steve said...

This reminds me so much of red dock and curly dock, which are definitely weeds around here, but which are sold as water plants around here as well. I have a plain houttuynia in our water garden and it's perfect there... of course, it's in a pot and it can't invade anything. I also have red dock in the pond, but there is curly dock running rampant everywhere else (we abut a conservation area and it comes from there). What is that quote... one man's weed is another man's perennial... or something like that!

Linnie W said...

Excellent investigative reporting on this plant. Nothing is worse than bringing in some pretty green terrorist to the garden-- thanks for the warning about this one!

greggo said...

Sinister indeed. It is rambling through a vinca minor bed as we speak. Tryed poisoning with picloram, which is a cut stump treatment product to keep suckers from coming back. Didn't even phase it. Not only is it in the ground cover it's under plastic, gravel, and bark that the last owners left. They should have to come back and clean it up. I should send you a photo.

b-a-g said...

Esther - It is an interesting and useful plant, but sometimes you can have too much of a good thing.

Donna & Greggo - it seems that you've seen houttuynia at its worst. Thanks for your cautionary tales.

Deb, Kallipso, Cathy & Steve - you have proved that this plant can be enjoyed if the gardener is informed and ensures that the roots are contained.

Thanks Linnie - It's red, yellow and green actually. Glad to be of service.

Elephant's Eye said...

It does have pretty leaves tho!

Masha said...

I love the look of those bright variegated leaves, but... "fishy mint"?? I certainly wouldn't eat that.

Alistair said...

I have the plain leafed Houttuynia with the small white double flowers, looks good at the pond edge. I suspect this one wouldn't be so invasive in the cooler Aberdeen climate.

PatioPatch said...

Hi b-a-g - hope it does not become as invasive as convulvulus. If it would just confine itself to difficult areas, it would be welcome. I like the variegation and the white flowers but find the pungency is more startling than anything vaguely aromatic. Have heard horror stories of this plant so now confine it to a basket in the wildlife pond - I can always drown it if needs be

One said...

I'm looking for a ground cover. Thanks for pointing out the plant that I should avoid.

The roots look like comfrey roots. I've just begun to grow comfrey. It's currently in a huge pot. I intend to transfer it to the ground where the compost it and hope I do not regret it.

b-a-g said...

Diana & Masha - The pretty leaves are decoys, to take your attention away from the roots.

Laura & Alastair - What a good idea to compliment essence of pondwater with fishy houttuynia aroma! Not so sure about drowning it though, it wouldn't surprise me if this adaptable plant has learnt how to float.

One - Bear in mind that any type of groundcover also takes up a lot of room underground. It may also be difficult to get rid of if you change your mind. Perennial groundcover is for life, not just for a season.

Janet said...

WE were given this plant as a present and duly planted it next to the stream and it took over. The roots were everywhere a bit like big couch grass. I'm sure it is still popping up in that garden.....

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