This is such a wonderful plant. blooms for me down to less than 20. if the soil stays a little wet will spread well. mine was covered in weeds and now that the weeds have been frosted, the vervain is showing up real well, dark green leaves and blooming.
I agree it's a little beauty, Arlene. Mine is still green, but starting to decline. I'm not sure it's getting quite enough sun. I have a volunteer beauty berry that grew much more quickly that I'd ever expected and seems to have shaded it more than it likes. Hopefully it will reseed itself and I will find it somewhere in the yard this spring!