Oleanders appear extensively in landscaping and gardens, particularly in areas with hot, dry summers and mild winters. They occur in a variety of shapes and sizes, ranging from 3-foot-tall mounding subshrubs to 20-foot-tall erect shrubs, but each bears an abundance of leathery, dark-green leaves and showy red, pink or white flowers. Oleanders are common in large landscaping plantings because they require little care and many gardeners seek to create additional plants from a single parent plant through at-home propagation. Cutting propagation is the best method for growing oleanders, and within a year the shrub will be ready to add to the garden.
Select several oleander cuttings early in the growing season when air temperatures reach 10 degrees Celsius. Choose cuttings from the tip of a healthy branch with a 6-inch-long, fairly straight stem.
Put on gloves. Grasp the oleander branch with one hand to steady it. Cut the stem at a 60-degree angle using bypass pruners. Remove the leaves from the bottom 3 inches of the oleander cutting. Set them aside.
Fill an 227gr. glass jar with water. Crush an 81-mg aspirin and stir it into the water until dissolved. Place the oleander cuttings in the aspirin water.
Place the oleander cuttings on a windowsill where they will receive bright light and constant warmth. Monitor the root growth. Plant the oleander cuttings once the roots reach 1 to 2 inches in length.
Fill an 8-inch plastic pot with rich, sterile potting soil for each oleander cutting. Saturate the potting soil with cool water and allow it to drain. Poke a 3-inch-deep hole in the centre of each pot of soil.
Insert the oleander cuttings into the premade holes and tamp the soil around their base. Water the oleander cuttings sparingly every day with 3 or 4 tbsp of water drizzled around the base of the plant.
Place the potted oleander cuttings outdoors where they will receive no more than two hours of direct sunlight each day. Slowly acclimate them to stronger light over the course of 10 days until they can stand direct sun without scorching.
Move the potted oleanders into a greenhouse or where they will receive protection from the elements during their first winter. Water to 1 inch every 10 days during the winter.
Move the oleanders outdoors the following spring when temperatures reach 15.6 degrees Celsius. Transplant them into a 1-gallon plastic pot filled with potting soil in mid-spring, or plant them outdoors in a permanent bed with full sun.
Hardwood and tip cuttings work equally well when propagating oleander and each uses the same method and materials. Oleanders grow best in USDA hardiness zones 8 through 11. Aspirin works as a root stimulant and can be used to substitute commercial rooting hormone in at-home propagation.
Wear gloves when working with oleander shrubs since all parts of the plant are toxic to humans.