Foot-long racemes of lavender flowers bloom in spring and will rebloom on and off in summer. The flowers at the base of the stem bloom first until the entire cluster has opened over the course of a week or more. After the flowers pass, showy blue calyxes that slowly turn silver remain on the dangling inflorescence. This vigorous climbing vine has rough, sandpaper-like leaves and it needs a sturdy support or trellis to climb on. Petrea racemosa flowers and reblooms for us reliably when grown in a container in northern zones.