I have this happening yo my plants leaves what is it and is it bad?
How can I take of the problem?
Certified GKH Gardening Expert
These are leaf galls and caused by pest activity.
Nasturtium actually act as a beneficial pest control by attracting pests to their leaves and flowers and saving other plants.
There is not management needed but you can spray with Neem Oil if you have a pest issue. Neem Oil is organic and safe for people, pets and bees.