I'm guessing it might be s. lyrata, purple knockout sage also I think s. sinaloensis has purple leaves and blue flowers. Helena

My Salvia lyrata doesn't bloom this time of year. Could it be a purple leaved coleus? They're in the same family as salvia (Lamiaceae) and have similar looking bloom spikes now. Some are actually rather showy.

It could be a form of Ajuga.(?)

SG

Thank you for all of your ideas so far. It was very tall, like a foot, so I know it is not Ajuga. The plant shape and leaves are like coral bells (heuchera) but the flower is definitely salvia like.
Any nurseries specialize in salvias?

Scutellaria flowers look similar to the salvias, don't know if there's blue ones though or if they bloom at this time either.

Another possibility is that it is Perilla frutescens, Shiso in Japan. Very Salvia like in habit, with small purple flowers in a fairly dense spike. Foliage is aromatic, and it is used to add color and flavor to pickled vegetables.