18"??
They plant them here along the freeways and they are 10 ft+ big monsters!
I have a yellow salvia madrensis planted next to a small sky blue plumbago that I hope will grow to the same size. Right now the salvia is about 5 ft tall and the plumbago is about 1 ft tall but both are in full bloom and I love that blue and yellow color combo. I have Westerland planted behind the salvia, lots of colors going on here! Still have to see if the salvia will withstand the frost here so I will be taking cutting just in case. Actually I'll just dig out the new shoots I just noticed, looks like this things wants to be a big spreader.
