Basic structure of dicotyledonous stem-Sunflower stem. Inner structure of dicotyledonous stem reveals epidermis, cortex and stele. Epidermis. Epidermis is protective in function and creates the outermost layer of the stem. Epidermis is a single layer of parenchymatous rectangular cells.
Culture. Plumbago is propagated from cuttings in the summer, but you can also grow it from seed. Plant plumbago in light, sandy, well-drained soils, spacing each shrub 36 to 60 inches apart to allow room to grow. If spaced properly, blue plumbago will naturally cascade in a fountain shape.
Growing 8 to 15 feet tall and 6 to 12 feet wide, French lilac shrubs have heart-shaped foliage that is dark green to blue and ranges from 2 to 5 inches long. French lilac shrubs require full sun to part shade and a range of soil varieties including heavy soil. Plant in USDA zones 3b to 7.