My garden is over-run with...

Acanthus mollis - bear's breeches. Tried to dig it out, but it is now coming up through my roses and clematis. At the moment, I am injecting Roundup stump killer directly into the stems.

Aquilegia and violets run rampant in our garden too! Although I love Welsh poppies so I do let those seed about....the trick is to pull off the seed heads before they pop...We also have to weed out teasel and foxgloves.And don't get me started on the forget-me-not....if you do forget they colonise your entire garden! Last year we had to dig up a large part of one herbaceous border as it was riddled with couch grass - managed to save some of the plants and we are now beginning to replant. On the plus side - weeding is good exercise

My garden slopes up steeply, so when I had new steps they stood out like a sore thumb, so planted variegated ivy for ground cover. I quite like the way it softens the edges of the steps and I let it grow across the risers, but it is now rampant in the beds.
I also have self sown aquilegia and poppies, but I love them and only remove the ones in really inappropriate places. I think some poppy seeds must have gone in the garden compost, because the veg plot is smothered this year, but easy to weed out or hoe.
Thistles abound in the lawn as neighbours do not touch their gardens at all, allowing seeds to blow over. I bought a Fiscar weed puller as advertised on TV. Works a treat but leaves large holes which need filling.Now the squirrels are using these holes to bury peanuts! Put out nuts for badgers because if I don't they dig up the garden! Love watching them in evenings, better than TV any day!

One person,s weed, is another's flower !. We actively encourage aquilegia (and violets, if we have any). The other plants that have been a pest are Lilly of the Valley and Bluebells, both of which we weed out continually.

Quite true tjspompa we love our Lily of the Valley and while we weed out any Spanish bluebells (because they are invasive) I have planted some English Bluebells in a shady spot in the garden.

Yes I hated pulling up the aquilegia but they were elbowing everything else aside.
Weird isn't it that alchemilla mollis (is that what you meant?) breeds so rampantly in some gardens and not in others. I have it, but not in an incontinent fashion. It mainly likes the shady corner near the compost heap, where it is very welcome.
Of the violets sweet violet and a purply leaf one (icelandic?) spread a little. Its the later flowering dog violet that is a little devil.

JessM, no the plant we have is Acanthus mollis, which is different from the one you have.

Oh my goodness! You did mean acanthus. So many people complain about the other little mollis. (means soft in Latin? So pretty when it is wet. Acanthus does not look very soft though)
Acanthus is a monster. machetes to get out of the back door?

Anything wild and native that has a pretty flower is welcome in my garden. The soil is so acid and the deer eat so much that those are what decide the limits. Also the climate: everywhere else in my region the ox-eye daisies are blooming. In my garden the buds haven't opened yet! And they can plonk themselves wherever they like. So in the parts of grass where the orange hawkweed and pignut is blossoming right now the grass won't be cut (with a scythe) until they have dropped their seed. Five years ago there was one orange hawkweed, now there are dozens. Five years ago there was one monkey flower, now there are hundreds. I love plants that look after themselves. I have my work cut out already just cutting grass and lopping back the bloody rhododendrons! I love forgetmenots (they struggle here) and violets and aquilegia and native bluebells. The weeds are rushes, dock, sorrel, ground elder, Japanese knotweed and Himalayan balsam. My husband pulls out bracken. Nothing else seems a problem after that lot.

Our garden was an old meadow until five years ago, so the creeping buttercups need constant vigilance, but at least they are fairly easy to pull up. The alchemilla mollis seems to have reached some strange places already but I leave most of it as it looks so pretty at the moment.

The worst thing I ever put in my garden is a bamboo that I planted five years ago when I had a big thing for bamboos! I've got two but one is quite well behaved, stays within bounds and never needs any attention. The other one is rampant, invasive and totally out of control. I keep attacking it but it seems to thrive on being attacked. DH says he thinks there are Japanese soldiers living in there who don't know the war is over! The only good thing is you're never short of canes of all sizes. Geranium Johnson's Blue is a bit of a thug. I cut mine into three this year and gave two pieces away and it has spread again this summer so you wouldn't know I'd touched it. I do love it though. Last but not least - grape hyacinths (muscari) plant a few and they'll have taken over in no time at all.

artygran, grape hyacinths didn't survive in my garden, even though the deer didn't eat them! A north-east facing, acid-soiled Scottish hillside is a challenging place to have a garden. Good thing I love a challenge!

ooh orange hawkweed is a lovely wildflower. Sounds like you have a few compensations up there in Scotland that we don't have in suburbia. Single most treasured thing in our garden are the spotted woodpeckers but they are down to his bird feeding and not my gardening.

In my folly, I planted pink perennial geraniums. They have taken over large areas of the garden and other nicer plants have suffered. Circumstances have made it hard for me to wield a spade this year, and the wretched things are just laughing at me. Other forms of perennial geraniums are not invasive, so why do garden centres stock the ones that are? I may have to resort to weedkiller!

Chinese lanterns - beautful in the autumn but not very pretty the rest of the year, and taking over everywhere, even coming up in the lawn. I reckon there must be a complete root system under there. I keep pulling up the new shoots but it's a losing battle.

jessm, yes, there are compensations to living in Scotland, not least that it's one of the most beautiful countries in the world. A northern marsh orchid has sprung up and flowered today in my front garden and another will flower in a day or two.

Our previous garden was covered with ground elder. I read somewhere that they did not like an acidic soil, and that was confirmed when I realised that this weed does not grow under the oak trees at the lake. So, I armed myself with bags of oaks leaves from friends gardens, and begged buckets of coffee grounds from cafes. I built a layer of almost a foot, way over 20 cm. This forced the ground elder to move its leafwork higher. In spring, I lifted up this layer of oak leaves, and the ground elder had its roots growing underneath this layer of oak leaves, making it much easier to pull out. I felt that I was winning.

Then we moved. And the new plot had 6 oak trees along the one fence. Really acidic soil, and the only weed so far is a kind of grass that has underground shoots, luckily not couch. Also rumex acetosa, but nothing as bad as the ground elder and the geraniums in the other garden.

I have a small patch of ground elder that was introduced with a plant a friend gave me. I am attacking it with super strength Round Up, just hope I have caught it before it gets a hold.

Oh yes those pink geraniums. go from cushions to duvets if you dont watch em.
On the plus side, parsley is seeding itself. Apparently letting a parsley plant run to seed and reproduce naturally is the best way - and lots of baby parsley has come through the winter and is just getting to reasonable size. A woman can never have too many vases or too much parsley I reckon.

I let the parsley run to seed on my allotment in Oxfordshire and we used to be cropping parsley for nine or ten months a year. It was great! Haven't been able to do it in W Scotland probably for several reasons such as being cooler, shorter summers, etc. Sage does well, also chives and mints and, oddly enough, the deer don't eat them, but they do eat tulips!

There is an old saying. Where Parsley thrives the apron rules.

Been a megga year for aquilegia here in the Midlands.

Great spelling Crimson. Botanists say that herbs like sage have evolved their pungent chemicals to deter things like deer.
I realised yesterday why i have some bare patches where neither annuals nor weeds have seeded is a sparrow dust bath habit.

My rockery used to be full of marestail. At first I did not know what it was so ignored it - the guineapig and rabbit loved it so it was kept down a bit. Then they both died and the marestail became rampant. At that point I found out what it was and started Proceedings against it - Pathclear twice a year for 6 years. I paid someone with a strong back to move out all the stones and remake the rockery into a series of little terraces and planted it up this spring with annual bedding (cheaper than perennials for a trial run) All looking beautiful up until I did a spot of weeding yesterday.

Guess what I found hiding behind a verbena?