Plumbago – Hardiness
Q: I planted several blue plumbago plants last spring. Their blue and white flowers were outstanding all spring and summer until the first frost. Will they make it through the winter?
A: Plumbago is also known as leadwort. However, confusingly, there are two different leadworts commonly sold in nurseries. One, Plumbago auriculata is a lanky half-hardy perennial, meaning it usually dies in winter here. The other, Ceratostigma plumbaginoides is a fully hardy groundcover.
The difference is that the first leadwort blooms all summer long while the second only makes blooms in fall. You have Plumbago auriculata, Cape leadwort. My advice is to cut dead stems back to four inches tall now and lightly mulch with pine straw. If the winter cold doesn’t kill them you’ll enjoy plumbago again this year. And if you see another plant which is also called leadwort, you’ll now know the difference.