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.
Plant spacing. Place the dwarf plants about 2 feet apart, Natal Plum 2-1/2 to 3 feet apart, and Boxwood Beauty can go 3 feet apart. Come out from the house 2 to 2-1/2 feet for the two smaller varieties, 3 feet for the larger one.Natal Plum and Boxwood Beauty have tiny spikes on the tips of their leaves, so they're best planted away from foot traffic-at least 3 feet.merald Blanket stays low-about 1-1/2 feet tall. Boxwood Beauty can be kept about 2 feet. Natal Plum grows large if you wait long enough but can be trimmed to 3 feet.