Friday, April 21, 2017

No One to Blame but Myself - Geranium sanguineum and Ajuga genevensis

Geranium sanguineum looks innocent, but it's a bloody nuisance to remove
Geranium sanguineum looks so innocent, but don't be fooled. I've tried ripping out this plant about five times and it keeps growing back!

I have weeds aplenty.

Some blow into my garden (dandelions, for instance), while others (looking at you, wild grape and oak seedlings) presumably are gifts from birds or squirrels.

That's OK. It's part of the gardening life. As I cover more ground with plants I do want in the garden, I anticipate gradually being able to displace some of those I don't want in the garden.

Meanwhile, I pull. And use the CobraHead.

But what really burns my biscuits are the plants that I add to the garden and then decide were awful, terrible, no-good mistakes that must be evicted.

Sometimes, I shovel-prune plants (looking at you, gardenia and Carolina allspice) because they have died. That's discouraging, but at least those mistakes don't come back to haunt me.

Other times, I have to work a bit harder to rip out overly aggressive / invasive plants (e.g., lemon balm, creeping raspberry, blue star creeper, sweet woodruff) that wear out their welcome, but at least those guys have the decency to leave for good when asked. (And when I say "asked," I mean ripped out of the ground.)

I had a tough time kicking out hardy blue plumbago. It kept trying to make a sly comeback with a stem or two here and there, but I think I've finally gotten rid of it.

Still, none of those compare to the challenge I've had removing Geranium sanguineum and Ajuga from my sticky clay soil.

This is a good time to note that there can be massive differences between the way different species from the same genus behave in the garden. What I'm trying to say is - Just because G. sanguineum has been a bully in my garden, don't tar all the other cranesbill geraniums with the same brush.

'Rozanne' hybrid geranium is a perfectly well-behaved herbaceous perennial that flowers for months. In my experience, it doesn't quite have the heat tolerance or drought tolerance to thrive in a tough-love garden setting in Tennessee, but it's still a very nice plant.

And 'Biokovo' cranesbill geranium (G. x cantabrigiense) is one of my favorite geraniums and one of the top groundcovers I've found for Tennessee. It's basically evergreen here, developing nice red tints to the foliage in winter, has nice flowers that attract bumble bees and expands at a manageable pace. If it goes someplace unwanted, I've found it easy as pie to lift up and remove or relocate a chunk.

Then there's G. sanguineum - bloody geranium. I suppose it's called 'bloody geranium' because of its bright red roots, but it deserves the name for being a bloody nuisance. OK, I'll give it props for being fairly tough and semi-evergreen, but it's quite aggressive. Once it's established, it starts spreading far and wide via deep (relative to the size of the above-ground plant) and thick roots.

Even small blood geranium clumps put down deep roots before they start spreading laterally.

Try to remove the plant and those roots tend to snap (at least when you're pulling them from sticky, heavy clay - sand or loam might be a different story). Leave any bits of roots in the soil and the plant will reemerge to laugh at you behind your back. There are places where I've dug wide holes 10 inches deep trying to get all the root fragments and the plant still pops up after I've backfilled or jumps up somewhere nearby. (I think it also spreads a bit by seeding, though fortunately the seedlings show up near the parent plant and the self-seeding has not been rampant.)

Meanwhile, I'm loathe to plant anything else where I've tried to evict the bloody geranium, because I worry that the geranium will pop up again and I'll have to dig up the whole area, damaging the new plant.

So right now, I have a number of holes and bare spots in the garden where I'm just waiting for the bloody geranium to re-emerge so I can dig up another missed root. I suspect this will continue for months. At least.

Ajuga genevensis returns after a weeding attempt
Ajuga genevensis after I tried ripping it out last winter. Clearly, I failed the first time around.

Ajuga genevensis is in the same category. Well, except that the roots don't go as deep and I haven't tried ripping out (yet) as many times as the bloody geranium.

Still, from the picture above, you can see that it hasn't been impressed by my eviction efforts. I thought I'd torn out a rather large, thick patch of A. genevensis last winter, but clearly all I did was prune it.

Once I had praised A. genevensis for being less aggressive (and more evergreen in Tennessee) than the typical Ajuga (A. reptans) that you usually find at plant nurseries. It's true that A. reptans spreads a bit faster and less predictably, but I've found all the Ajugas are challenging to remove through hand pulling.

I hope my experiences save some other gardeners time, effort and hair-pulling.

Meanwhile, I continue to evaluate groundcover alternatives, focusing on natives. As I mentioned in a recent post, I think that effort is bearing fruit.

I'll keep observing and plan to post an update either at the end of this year or next spring with an overview of the best groundcover candidates so far.

How about in your garden? Have you planted anything aggressive that you later regretted? If so, did you succeed in evicting it or have you given up and simply found a way to live with it?


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