Lupins are hardy perennials that prefer acidic soil. They need moist soil, which is why I wonder you have them in pots as pots are great for keeping plants dry. I wonder if having them in pots is keeping them too dry. They also die back during winter. I would pop them in the ground.

Thank you for speedy response. The packet says plants need cold frame protection after autumn sowing before planting out in Spring. Also plants are with me in France at the moment, returning to UK in 2 weeks time. I can then plant them in Dorset garden or pot them on.

Hello and welcome to GOY 2homes I am so looking to following your wonderful project .

Before and after photos or in progress .

You could carefully turn one out of the pot and see if anything is eating them? Little c shaped grubs would be vine weevil. Or maybe they are too wet or too dry!! Check the drainage holes too. A little detective work is needed!!

Thanks for advice. The ones that are not thriving have a very poor root action and look as if they may be rotting at ground level. No sign of any infestation. I will put them out in the soil when I return to the UK and hope for the best. I can always try again in the Spring.