Grey Squirrel or Meghan Markle
OK, I was going to name this thread Troublesome Plants as I'm thoroughly bored of the cats debate. This is probably something you've equally debated before but I'll explain my question for a thundery day.
We had to spend much of last year trying (I think in vain) to clear the local riverbank of Himalayan Balsam, which I believe was first imported in the 1830's as a greenhouse plant but is now an invasive pest. I believe it's also known as Policeman's Helmet for those following the Common Names thread. The last couple of years our canal bank has been overrun by what I think is Rhodedendron Purple Splendour, which although giving a couple of weeks delightful colour is otherwise crowding everything else out. However, it is still sold by lots of garden centres.
Last night on the Chelsea Flower show Monty introduced a piece as "what are the new plants we're all going to be off to buy this weekend" and they started showing Himalayan Poppies and other exotics.
So, back to my question - how do you know when an overseas import is going to become a generally unwelcome invasive species like the Grey Squirrel, or is going to just stand quietly in the corner not doing much but looking nice (i.e. Meghan)? It seems to me these things are always added to lists of invasive species after they've escaped from the gardening world into the wild and not before (that's the grey squirrels again, not Meghan). Do we take any precaution? Do we care?
“Success is the ability to go from one failure to another with no loss of enthusiasm.” Winston Churchill