Can varieties be added to plant database for Russian Sage? I would like to add the varieties i.e. Lacy Blue.

It's already there: Russian Sage (Salvia Lacey Blue®)

Often, spellings will be slightly different. I usually search using less characters rather than more, e.g., I found this by searching "Sage Lac Blue"

Edited to add: That search also brought up 2 other sages with either blue or lac in their name, but easy enough to pick out the correct one.

This is a good example of a name that can be added to the Also sold as field. Done.