If it is true that nasturiums grow best in "infertile" soil as some sites say, what is "infertile" soil? I'm assuming it means "don't add compost" but does it mean start w/ just topsoil or actually go full on and plant in sand or rock?
Best Soil for Nasturiums
Certified GKH Gardening Expert
It pretty much means that you can grow this plant basically anywhere that provides plenty of sunlight and in any soil type as long as it drains well. Nastutiums are not too picky about where they are grown.
nasturtiums do not like really GOOD soil. the worst soil in your yard, in full sun, and on the dry side, will ensure beautiful blooms.