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.
Standard trees grown from seed require more space than those made by grafting onto a dwarf or semi-dwarf rootstock. Full size fruit trees generally should have 20 to 24 foot spacing. In the case of apple trees, the standard full-sized trees should be planted in a 35â² by 35â² area, at least 25 to 30 feet apart.Semi-dwarf apple rootstocks only need to be planted in a 12â² by 12â² area, or about 10 to 20 feet apart.Dwarf apple trees only require a 10â² by 10â² area, or 8 to 12 feet apart.ig trees should be planted in an area 20â² to 30â² square in a sunny location. Citrus trees need to be planted 8 feet apart. Dwarf apple, sweet cherry, peach and plum trees can be planted in a 10â² by 10â² area. Dwarfed pear trees, however, need a space of 12 feet by 12 feet.