Sadly, this probably came from a region of the UK where the flat-worm has already established. The damage was done in the past and current phyto-sanitary regulations (Hurray for the EU!) should stop further unwelcome introductions.

Historically, most exotics were introduced as seeds collected by the great plant hunters (Forrest etc.) in the early twentieth century. It was more recently that live plants were imported and the regulations were to late to prevent introduction of some pathogens and pests.

And more sensible to remove the address from the posting.

I bought a plant from a local nursery last year and luckily I had a close look at the roots before just planting it. I had also bought New Zealand flatworms. The nursery were not interested so I have told everyone I know that they have it. The egg cases look a little like a shrivelled blackcurrant, in shape, colour and size.

as for treating the RHS suggest putting sections of plastic sheeting down as the worms will collect on the under surface like slugs do. Then its a case of dropping them into boiling water. There are platyhelminthicides [don't know if available for the home gardener] but I suspect not good for the native species of flat worms.

What is more of a worry are the gardeners who 'smuggle' plant material across continents between friends etc.

I pm Nigel to remove address

Agree with Buddlejagar that the worm is probably home grown and that plants from outwith the EU require strict sanitry proceedures. Actually, it has been shown that the worm population, European and Australation has reached a balance and our 'good' worms are now thriving.

It's not only worms, larvae and insects, etc, that are being brought in on imported plants. Plant diseases and viruses are also a big problem that could be devastating. Look what happened in Ireland in the mid 1800's when the potato blight decimated the crop. The disease is believed to have come from America.

I believe that a lot of pests that we have seen come into our gardens have come from abroad, it is only during the last few years we have had the leeks infected by some insect that leave it inedible so now I am thinking of not growing leeks for a few years and see if it will die out on my plot.

And think of the ash die back, the oak sudden death and the horse chestnut leaf miner......imagine our country without these beautiful trees

Interesting read I'll definitely be taking a closer look at the roots of any plants I buy from now on.
Oh the horse chestnut leaf miner is awful Pam we have two lovely trees(well they were) with preservation orders, every year they're affected as are every other tree in our street they look awful in the summer, such a shame and as there are so many other nearby trees heaven knows how it could be treated.

Ours were better last year, I did send a leaf away and got a nice letter back, they are charting its progress.
I will say though that although they look bad the tree itself seems unaffected, last year it still had flowers and a good crop of conkers.
something to do with the timing of the leaf miner I think after it has done its growing for the year (hope so anyway)