White or pink flowers open all summer above long evergreen leaves typical of Mediterranean flora: oleander (Nerium oleander) is a 3 to 10 foot shrub for hedges, windbreaks or standing alone. Give it full sun and free-draining soil and it flowers for months on end — though every part of it is highly toxic.
| Name | Nerium oleander |
|---|---|
| Family | Apocynceae or dogbane |
| Type | shrub, bay |
| Height | 3 to 10 feet (1 to 3 m) |
| Exposure | full sun |
| Soil | ordinary, well drained |
| Foliage | evergreen |
| Flowering | from early summer to early autumn |
Pruning, caring for and watering oleander helps increase flowering, growth and avoid diseases. Take note, though, that this beauty comes at a price. The entire plant is highly toxic, and ingesting a single leaf can be fatal even to adults. In some places it’s also considered invasive.
Oleander planting, when done correctly, ensures that it sets in and develops well. Planting is a critical step.
Preferably done in fall or spring, planting oleander is an important step because it guarantees that the shrub will develop correctly.
Choose a sun-bathed area, sheltered from stronger winds. Amend the dirt in your garden with soil mix to ensure proper drainage and access to nutrients for your oleander.
Adding tomato or vegetable fertilizer is a particularly effective trick to produce abundant flowers all summer long.
Planting oleander in pots or garden boxes is perfectly possible and even recommended in regions where it freezes in the winter.
Similarly to planting directly in the ground, choose again a place that is well exposed to the sun and sheltered from wind.
More so than with oleander planted in the ground, soil mix in pots quickly loses its nutritional value. Adding tomato fertilizer is a definite “plus” to continue producing abundant flowers.
Making cuttings is the easiest and fastest technique to propagate oleander.
Traditionally, oleander cuttings are most successful in late summer but it is perfectly possible to start a bit earlier, in early summer or midsummer.
Even though it isn’t required, pruning oleander may serve to boost flowering and thicken the bush.
But take note that oleander flowers only on wood stems from the previous year, so it’s better to not prune it all at once since this would lead to a year without flowers.
The idea is to prune ⅓ of the branches every year (as in, “one in three”), so that you cover the entire bush within three years.
As for regular care, oleander can get by with very little care once it is comfortably settled in.
At the very beginning of spring,
After flowering and before bringing your potted oleander in for the winter, cut back ⅓ of the branches to half their length to maintain a nice, tight silhouette.
Every year, proceed to pruning again another third of the branches so that the whole of the shrub is pruned over a three-year cycle.
If you live in a zone where there is little or no freezing, you can leave oleander outdoors without any manner of protection.
But if it freezes in your zone, protect your oleander with a winterizing cover.
In most cases, it is either a water supply problem or a problem related to freezing.
Oleander is vulnerable to several diseases and parasites, often resulting in yellowing leaves or white marks.
Correct watering and adding a good dose of fertilizer is often enough to strengthen it and let it fight back the diseases.
Regularly applying Bordeaux mixture acts as a deterrent against most types of fungus such as leaf spot septoriosis due to Septoria nerii.
Most oleander setbacks show up first on the leaves. Match what you can see to the right cause before reaching for a treatment.
| Problem | What you see | What to do |
|---|---|---|
| Water excess / poor drainage | Leaves yellow, then turn brown and fall | Improve drainage with sand and pebbles, or drainage holes in pots |
| Frost damage | Branches and leaves dried off or blackened in spring | Cut just below the damaged zone; the shrub recovers |
| Scale insects | A white accretion resembling cotton | Correct watering and fertiliser to strengthen the shrub |
| Oleander knot / nerium canker | Small brown, round spots on the leaves | Remove affected parts and keep the plant well fed |
| Aphids | Leaves curl up and turn black before falling | Treat as for aphids on any shrub; rarely fatal |
| Leaf spot septoriosis (Septoria nerii) | Fungal spotting on the foliage | Apply Bordeaux mixture regularly as a deterrent |
Correct watering and a good dose of fertiliser are often enough to let the shrub fight back on its own.
This shrub produces beautiful white or pink flowers all summer long. Its long leaves are typical of Mediterranean plant flora.
Use in hedges, wind-breakers or simply standing alone. Oleander needs mulch in winter to protect its leaves and roots from the cold.
In summer, water in abundance during heat waves, especially for oleander in pots.
Easy to care for and to grow, oleander is without doubt one of the most beautiful summer-flowering shrubs.
Trigger massive flower-bearing with fertilizer suited to tomatoes and vegetables.
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When watering in the summer, choose to water in the evening to avoid evaporation.
Watch out for the plant’s toxicity: coming in hand or mouth contact with the plant is dangerous for health. Wear gloves and teach children not to play with it.
Oleander’s hardiness depends on your climate zone and cultivar. Some varieties can tolerate temperatures as low as 5°F (-15°C), but in areas where it freezes, you should protect the plant with a winterizing cover and mulch at the base. Young oleander plants benefit especially from winter protection, and if branches freeze and blacken, they must be removed as they won’t grow back.
Yes, oleander is highly toxic—the entire plant is dangerous and ingesting even a single leaf can be fatal to adults. The article emphasizes wearing gloves when handling the plant and teaching children not to play with it, as hand or mouth contact with the plant is dangerous for health.
Yes, growing oleander in pots is recommended, especially in regions where it freezes in winter. In summer, mulch the base to keep roots moist, and in winter, bring the potted plant indoors to a light-bathed, cool location like an unheated greenhouse where it won’t freeze.
In summer, water potted oleander generously during hot weather, checking that drainage holes allow excess water to flow out. For oleander in the ground, ensure well-drained soil with added sand and pebbles to prevent water excess, which causes yellowing leaves. Water in the evening to avoid evaporation.
Oleander flowers only on wood stems from the previous year, so pruning the entire bush at once will result in a year without flowers. To maintain blooms, prune only ⅓ of the branches each year over a three-year cycle. Additionally, apply tomato or vegetable fertilizer to trigger abundant flowering throughout summer.
Just found very useful information about my standard oleander, bought it last spring didn’t know much about it and it got huge in summer
Oleander does grow prolifically when in the proper growing environment. And the blooms are very beautiful!