How to Plant and Grow Oleander

Oleander (Nerium oleander) is a tough shrub that is a sturdy ornamental addition to landscapes in warm areas (it won't tolerate a hard freeze). It's versatile and useful as a border, hedge, or screening plant, and a good pick for a potted plant.

Oleander flowers emerge at the tips of stems for a flush of pink or white. The flowers typically have a single row of petals, but some varieties set a double row of petals for a better show. They stand out against long, narrow, bright green leaves with a light midrib, making them reminiscent of olive trees.

All parts of the oleander shrub are highly toxic to humans, dogs, cats and horses. Unlike some plants that have one toxic compound, oleander has several. Also, be careful when pruning oleander because the milky sap can cause skin irritation. Even dried plant parts remain toxic.

Where to Plant Oleander

Plant oleander in full sun for the best results. It will grow in partial shade, but the shrub may become lanky. It tolerates most soil types as long as they drain well. Don't plant it near areas where children and pets play.

Oleander can be used as a living wall or screen, maintained as a specimen shrub, or trained as a small tree.

How and When to Plant Oleander

Plant oleander in early spring while the shrub is still dormant or in late summer or early fall after it stops blooming. Dig a hole two or three times as wide and exactly as tall as the nursery container. Amend the soil with compost or organic matter if needed for good drainage. Remove the oleander from its container and position it so it sits at precisely the same height in the soil as it did in the container. The base of the main stem should be at soil level, not below.

Fill the hole halfway with the amended soil and add water. Wait a few minutes and fill the hole the rest of the way with soil. Keep the leaves dry as you water the base of the plant again.

Oleander Care Tips

Once established, oleander requires little maintenance.

Light

Oleander grows fast and can develop a lanky habit if not correctly maintained. One of the best ways to create the densest habit possible is to plant it in full sun, which also encourages the most blossoms. Oleander tolerates part shade, but in those conditions, it requires staking to prevent flopping and needs frequent pruning.

Soil and Water

Oleander is drought-tolerant and does well in poor soil. If the roots stay wet for long, it is prone to rot, so excellent drainage is essential.

Temperature and Humidity

Although they grow in warm zones, most oleanders can survive a temperature that drops to freezing for a short period, but damage to the foliage may occur. Gardeners who live in areas where the temperature routinely drops to freezing should move their oleanders indoors for the winter.

Oleander grows best in an average humidity of about 40 percent.

Fertilizer

Oleanders in the landscape don't need much fertilizer. A slow-release, balanced granular fertilizer, such as a 10-10-10 formulation, can be applied in the spring and again in the fall, following the product's instructions.

Oleanders planted in containers require more frequent fertilization. Apply the same fertilizer as for landscape plants every four weeks during the growing season.

Pruning

Oleander shrubs should be pruned in late summer or early fall to give any new growth time to harden off before winter temperatures arrive. Remove any diseased, dead or damaged stems, making the needed cut just above a leaf node to encourage branching. Limit the pruning to no more than one-third of the foliage.

Potting and Repotting Oleander

In many parts of the country, oleander can't survive the winter temperatures. In climates where oleander isn't hardy, it can be planted in containers that are moved inside when the weather turns cold. Select a large container with good drainage and a small or medium-sized oleander. Fill the container with potting soil or garden soil amended with compost or other organic matter, and plant the shrub so the stem base is at soil level. Water the shrub and position it in a sunny spot for the warm months. Although oleander plants in the garden are drought-tolerant, those in containers need to be watered regularly and fertilized every two weeks during the blooming period with a granular or liquid balanced fertilizer, following the product directions.

As winter approaches, move the container into a cool, sheltered area, such as a garage or basement, where it is protected from freezing temperatures. Cut the plant back by one-third to make it easier to manage. In the spring, move the container back out to the garden gradually, leaving it for a couple of hours the first day and then increasing the time a little each day.

Although oleander can be repotted if needed, cutting it back by one-third each year should keep it a manageable size.

Pests and Problems

Aphids, spider mites, and scales are familiar garden pests that sometimes appear on oleander shrubs. They can be treated with a strong stream of water or an application of insecticidal soap or neem oil.

The oleander caterpillar is more challenging to treat. Even through the leaves of oleander shrubs are highly toxic to most animals, they are a delicious meal for the oleander caterpillar. An infestation may require two or three treatments, preferably with a product containing Bacillus thuringiensis.

How to Propagate Oleander

Oleander can be propagated via stem cuttings or seed.

Cuttings: Oleander is easy to propagate with stem cuttings. Choose several 10- to 12-inch semi-ripe wood cuttings from a plant stem or from material you have pruned off the shrub. Old woody growth doesn't root well. Make the cut just below a leaf node and remove the foliage from the bottom half of the cutting, leaving a few leaves at the top. Also, remove any flower heads. Dip the bottom of each cutting in rooting hormone and put it in a pot filled with good-quality potting soil, firming the soil around the stem. Water the pot and cover it and the cutting with a clear plastic bag. Keep the pot in a warm, bright place, watering as needed to keep the soil moist until the cutting roots, as evidenced by new growth or resistance to a slight tug on one of the leaves. Remove the plastic bag and move the pot into an area that receives partial sunlight to continue the rooting process.

Seeds: Harvest the seed pod of a mature oleander when it turns brown and dries out, but before it pops open and spills its seeds. Fill a small pot with moistened seed-starting mix and press a seed into the planting medium, but don't cover it with soil. Cover the pot with plastic wrap and put it in a warm area at about 68°F and under grow lights. Mist the soil occasionally to keep it moist. Germination takes a while—one to three months. Remove the plastic wrap when the seeds sprout. In a few weeks, the root system will be robust, and you can move the seedlings to a larger pot or outside if you live in a warm area where oleander is hardy.

Types of Oleander

'Pink Beauty' Oleander

Nerium oleander 'Pink Beauty' cultivar bears large, clear-pink flowers with little or no fragrance. It grows 20 feet tall and 12 feet wide and tolerates light frosts better than most oleander varieties. Zones 9-11

'Mrs. Lucille Hutchings' Oleander

Nerium oleander 'Mrs. Lucille Hutchings' is a large variety with showy, peachy-pink double flowers. It grows 20 feet tall and 10 feet wide. Zones 9-11

'Hardy Pink' Oleander

Nerium oleander 'Hardy Pink' forms an open, upright plant that grows 15 feet tall and 10 feet wide with clusters of rose-pink flowers all summer. Zones 9-11

White Oleander

Nerium oleander 'Album' offers white flowers throughout the summer on a big plant 18 feet tall and 10 feet wide. Zones 10-11

'Tangier' Oleander

Nerium oleander 'Tangier' produces light pink blooms on a big shrub 20 feet tall and 10 feet wide. Zones 10-11