Care for an oleander tree or shrub by choosing a location with full or partial access to sun, planting it in rich, well-drained coil, watering it well and applying fertilizer once a year. Because this plant isn't cold-hardy, take it inside during the winter in climates that reach freezing temperatures or plant it next to a wall for better heat retention.
First, choose a site that receives partial to full sun with protection from the cold and good air circulation. The soil needs to be well-drained and enriched with compost. For colder climates, plant the oleander bush in a container with potting mix amended with organic material. Care for the plant by watering it regularly, especially in hot, dry climates. In areas that do not receive regular rainfall, water the plant deeply and never let the soil dry out completely during waterings.
Once a year in the spring, feed the oleander tree balanced fertilizer. Prune the plant regularly every late summer to early fall by clipping the limbs back to the nearest leaf node. Snip off any dead and faded flowers. This bush requires hard pruning every couple of years to keep it from becoming overgrown depending on the cultivar.