Trachelium caeruleum - Throatwort

Trachelium caeruleum grows well in light shade to full sun. The leaves are ovate and lightly dentate. They carry a bit of red on the veins and stems. Trachelium caeruleum is a sub-shrub that grows to about 3 feet. I occasionally get one to grow a second season. I often get seedlings but not too many so as to call them weeds. Throatwort has a great late spring through fall bloom. Trachelium caeruleum will continue to bloom with its flat heads of small purple flowers if the dead flowers are removed. Trachelium caeruleum has survived in my yard to the low 20°s F. I think it did so because it was able to harden off, as it was killed by less intense cold nearer the coast. The flowers are in 3" umbels at the ends of the branches.