Oleander, or Nerium oleander, is an evergreen perennial shrub that thrives in hot climates. Once established, this hardy shrub requires little care and, if left unpruned, can grow up to 20 feet tall. The oleander's leaves are long and deep green. Depending upon the variety, the shrub produces fragrant blossoms in white, yellow, pink, apricot, cerise or scarlet from June to November.
Site and Soil
Oleander needs a site that receives full sun yet is sheltered from cold winds. In USDA zones 8 to 11, oleander can be left outside throughout the year. In other areas, it needs to be planted in a container and kept indoors until late May when it can be moved outdoors. Except for clay, oleander does well in most types of soil as long as it is well drained.
When planting oleander in the garden, dig a hole that is twice the size of the container the shrub comes in. Remove the plant from the container and place it in the hole, being careful not to damage the root ball. Place the soil around the roots to halfway and water gently to settle the soil around the roots. Finish filling the hole, tamp down gently and water again.
When planting oleander in a container, choose a container that is large enough to hold the mature plant. Make sure the pot has drainage holes and use a container saucer. Fill the pot 1/3 full of potting soil, place the oleander in it and fill the pot about half full with soil. Water gently to settle the soil around the roots. Finish filling the soil in the pot, tamp down gently and water again. Set the container in a location where it receives full sun, like in a conservatory.
Water the shrub regularly, especially during long dry spells, but do not overwater. To promote large blossoms in oleanders planted in a garden, sprinkle bone meal over the root area in the spring and fall and gently hoe it into the soil. For container shrubs, sprinkle slow-release fertiliser granules in the spring. Limpet-like scale insects are sometimes a problem for oleander; treat with malathion or horticultural soap every 2 weeks. After flowers fade, trim the shoots by half their length. In the spring, shape the bush by trimming 4 inches off the side shoots. If the oleander becomes root-bound, repot it in the spring.
Oleander is quite toxic. Keep children and pets away and wear protective gloves when handling seeds.