Hello Rogi, Are they flowering now, could they be Japanese anemonies? if so then they are perennial and will come back year after year, they have long roots and can be very invasive but in a nice way, is this a new garden you have? Julien

This confused me, Rogi, and I had to look it up (Wiki). Do you mean that these are Bush Anemonies (Carpenteria californica)? These are generally Mediteranean plants but some frost hardy cultivars (-15C) have been produced and are seemingly popular in British gardens.
I am sorry but I don't knowe any more about them, least of all pruning. If you don't get more answeres you could always look them up on the web.

Hallo Julien and Bulbaholic. Thanks for your answers. @ Julien...yes I forgot to say they are Japanese Anemonies. They are flowering at the moment...as you say they have very long roots and are springing up everywhere...even where they are not wanted..hihi. This is the garden at my Datcha that I bought a couple of months ago and my neighbours tell me that they have been there for many years...the Anemonies...not the neighbours...but most of the neighbours have been there for years too !.

Japanese anenomes are incredibly tough. One of my customers had a large section of garden full of them and I used to hoe them off each year and they came back every year.

I use a hedge trimmer to take off the stems at a height of about 1 inch when they've finished flowering and this is very effective,very quick and slightly less drastic than hoeing.

Don't worry you'll have japanese anenomes coming up every year virtually whatever you do to them !

Someone I know runs a lawn mower over his and they flower beautifully the following year!

Thanks for replying Anchorman. Tomorrow they will get the chop with the shears !.

Although they won't come to any harm being tough with them now Rogi it might be better to leave them a couple of weeks longer before trimming them.

Been spraying the ones in my garden with Roundup for 12 years now, still they grow.

Hello Rogi, Are you keeping the anemonies ?, or do you want to eradicate some or all of them?, if so then cut back the spent flowers before more seed drops, why not concentrate on one area at a time and by useing a good mathook, grub them out, but go deep, a good trench spade is a usefull tool for tackling the deep roots, have used these methods to great effect over the years , hope this helps. julien

Thanks for all your answers. Yesterday I cut them back with the garden shears, the place looks a lot more tidy now.