Posted: 16/03/2015 at 21:28
The Purple Toadflax (Linaria) can get a bit thuggish if it seeds into permanent planters, mainly as it continues growing over the winter, pretty much unseen. Once you let it seed, you will have it forever (like most of the willowherbs!) It is quite pretty though.
As for the bluebells, you can tell as the bulbs are white and are quite deep. I'm also plagued by the spanish variety and forever digging them up but just can't seem to get rid of them..