In the garden in Dublin and Limerick.
Very easy to weed out.
Plants from 20cm to maybe 50cm tall.
Small pink flowers, red blush on stem/leaves/roots. Red nodules on roots. Cottony fluff on seeds.
Flowers in little funnel with have 10 petals, light yellow on inside.
Found it here first:
American Willowherb - Epilobium ciliatum
"an immigrant from across the Atlantic that took big time to its new abode. It was first recorded in 1958 in Arklow but wasn’t until the 1980’s that it started to spread. It’s now found in all corners of the Irish countryside."
Interesting. Another willowherb.
Ireland https://maps.biodiversityireland.ie/Species/41421
Finland https://luontoportti.com/en/t/1046/american-willowherb
UK https://www.naturespot.org.uk/species/american-willowherb
Looks quite like this one: http://www.gardenwithoutdoors.org.uk/weed_guide#short-fruited_willowherb
http://www.wildflowersofireland.net/plant_detail.php?id_flower=583&Wildflower=Willowherb,%20American
http://www.irishwildflowers.ie/pages/195a.html
https://wildflowerfinder.org.uk/Flowers/W/Willowherb(American)/Willowherb(American).htm