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.
Till the soil and rake in manure, compost, blood or bone meal at a depth of 10 to 15 inches (25 to 38 cm). 1  Dig trenches for planting. 2  Trenches should be 6 to 12 inches (15 to 30 cm) deep and around 12 inches (30 cm) wide. 3  If you are planting multiple rows, space the trenches 2 to 3 feet (0.6 to 0.9 m) apart.sparagus seeds require 3 years to grow before they are ready to be harvested. During their first season the seeds germinate and sprout, and after that they need 2 years to establish their long, spongy roots deep into the soil.