This is my first year to try to grow dahlias. I have red clay soil to China so decided I should grow them in containers. I have watched several Youtube videos & in one the lady said when the dahlias have sprouted & are a few inches tall you need to add soil to the container. Do any of you grow in containers & if so do you add soil?

Welcome to the Dahlias forum, sallysmom! I hope this is a great first year for you.

I grow the majority of my dahlias in the ground, but I have a little "pot garden" with about 25+ on my back patio. I use top soil and composted manure in my pots (both purchased, not out of my own garden), about a 50/50 mix. I also water and fertilize the pots more than I do the ones that are in the ground.