..of the plant variety, also known as self-seeders. Here are a few which are always welcome here.
This beautiful and quite large aquilegia appeared through the privet hedge - who knows where it came from. I will collect seed from it.
This soft lavender one came from a garden two doors down. I will collect seed from this one too, as I would like to have it throughout this whole bed. They grow so easily among other things, never crowding them out, unlike the wild pink campion behind which is spreading wildly, but is easy to pull out where you don't need it. I have masses of it this year. I also have some varieties of white campion sown from seed last year and happily coming back this year. Later flowering so no photos yet.
The Welsh poppy in both orange and yellow is hidden from view behind some large shrubs which is a pity - I'll scatter lots of seed around as it is another one which flowers at a useful time and doesn't become a nuisance here.
Perhaps my favourite. Geranium robertianum 'Celtic White' grown from seed many years ago has sprinkled itself about delightfully especially in the gravel areas. Again easy to pull out where not required they give the garden the slightly wild and natural look I am trying to cultivate.