Invasive Geranium

[mark smyth]

I have an invasive Geranium taking over the whole garden, front and back, its in pots and now I've seen it in the sand plunge. What is it?

[Martin Baxendale]

At least it looks easy to uproot - unlike my ever-more-invasive Cardamine quinquefolia.

[Jacek]

Isn't it an annual weed, Geranium pusillum?

[Alan_b]

Herb Robert (Geranium robertianum) tends to do this in my garden.  It certainly has the red stems of the one in your picture and likes to pop-up in pots but the leaves are more fern-like than yours seem to be.

[johnralphcarpenter]

Dove's-foot Crane's-bill - Geranium molle. An annual native plant. I have it too and rather like it.

[mark smyth]

THanks John.

I have an invasion of herb Robert also. In the autumn I removed every one I could find and now its as bad as ever

[Tiggrx]

It looks like Geranium lucidum. Pretty but very prolific.

[johnralphcarpenter]

Yep, could be that too. Both G. molle and G. lucidum are pretty widespread.

[Ed Alverson]

It looks like Geranium lucidum. Pretty but very prolific.

I agree with G. lucidum - G. molle doesn't have that shiny red look.

This species has become a horrible invasive in parts of western Oregon - not just a garden weed, but covering the understory over entire hillsides with natural vegetation, excluding most or all of the native herbaceous plants. It also is spreading and has been found in a few places in western Washington and northern California - poised to take over millions of acreas of woodland understory where the climate is suitable.

See, for example, http://www.kingcounty.gov/environment/animalsAndPlants/noxious-weeds/weed-identification/shiny-geranium.aspx.

I've heard it said that it is allelopathic. Australia and New Zealand also better watch out if it makes it there.

Yes, it is easy to pull, but I've not seen a place where anyone has been able to weed it out completely. There is a patch in a yard a couple of blocks from my house and I am now worried that it will spread into my yard...

[ChrisB]

Good heavens it sounds horrendous.  I've not seen it here yet but if Marks got it will it travel?  Hope not....

[mark smyth]

Allelopathy
http://en.wikipedia.org/wiki/Allelopathy

[mark smyth]

At least it looks easy to uproot - unlike my ever-more-invasive Cardamine quinquefolia.

very easy to pull

[mark smyth]

For £1000 Kew will allow you to adopt this plant 
http://www.kew.org/support-kew/adopt-a-seed/geranium-lucidum.htm

[johnralphcarpenter]

I have Herb Robert, Geranium robertianum, popping up everywhere and I don't mind a bit! As to the other one, now identified as Geranium lucidum, it self seeds in gravel between pots and looks very nice; not yet in flower however.

[Ed Alverson]

For £1000 Kew will allow you to adopt this plant 
http://www.kew.org/support-kew/adopt-a-seed/geranium-lucidum.htm

Now that is hilarious!

In Kew's defense, the plant that is taking over the world may not be the same genetically as the pretty wildflower - it could, for example, but a cross between two different strains of G. lucidum from different regions that were brought together to form what might be called an intraspecific hybrid, and thus exhibiting heterosis or hybrid vigor. So it would be interesting to compare the genetics of the garden weed with the "wildflower" to see if they were any different.