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Oleander, the South brings sun to the garden


Oleander is a beautiful shrub that blooms all summer long.

Summary of key Oleander facts

NameNerium oleander
FamilyApocynceae 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 June to September

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.

Planting oleander

Oleander planting, when done correctly, ensures that it sets in and develops well. Planting is a critical step.

Planting oleander directly in the ground

Preferably done in fall or spring, planting oleander is an important step because it guarantees that the shrub will develop correctly.

Oleander plantingChoose 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

Planting oleander in pots or garden boxes is perfectly possible and even recommended in regions where it freezes in the winter.

Oleander in a potSimilarly to planting directly in the ground, choose again a place that is well exposed to the sun and sheltered from wind.

  • Set the shrub in soil mix because, since it is in a pot, this will help roots develop.
  • Soil mix ensures that water will be retained as long as possible, and will also provide the organic matter needed for it to grow.
  • In summer, feel free to mulch the base of your oleander plants to keep the roots sufficiently moist.
  • In winter, bring your plant indoors, in a light-bathed place that may be cool but that will not freeze, like a greenhouse without any heating.

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.

Propagating oleander

Making cuttings is the easiest and fastest technique to propagate oleander.

Traditionally, oleander cuttings are most successful in August but it is perfectly possible to start a bit earlier, in June or July.

Pruning and caring for oleander

Seed pods of oleander with flowersEven 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.

Pruning oleander planted in the ground

At the very beginning of spring,

  • Prune ⅓ of the branches to around ⅓ of their length for the shrub to recover its vigor.
  • You can easily cut back even to 20 inches (50 cm) without any dire consequences since oleander are not set back by pruning.
  • In the case that oleander has frozen over during the winter, the blackened branches must be removed entirely since they won’t grow back.

Pruning oleander planted in pots

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.

Winterizing oleander against freezing

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.

  • Depending on the cultivar, hardiness can overcome temperatures as low as 5°F (-15°C) but young oleander will always be the better for having been well winterized.
  • Mulching the foot of the shrub and a winterizing cover are the best protections possible against freezing.

What is to be done if leaves turn yellow?

In most cases, it is either a water supply problem or a problem related to freezing.

Watering oleander

  • Oleander requires planting in well drained soil, because any water excess leads to yellowing leaves that turn brown and fall off.
  • In summer, water generously when it is hot, especially for potted oleander.
  • If in pots, check that the bottom has drainage holes for excess water to flow out.
  • If in the ground, do mix sand into the soil and add pebbles or clay pebbles at the bottom of the hole to increase drainage.

Oleander that has frozen over

  • Oleander is vulnerable to strong frost spells.
  • If branches have dried off together with leaves in the spring, remove impacted parts by simply cutting them off just below the damaged zone, and your oleander will recover normally.
  • If the whole shrub is hit, there is a strong chance that it will not survive.

Diseases and parasites attacking oleander

Yellow aphids on oleander leavesOleander 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.

Learn more about oleander

This shrub produces beautiful white or pink flowers all summer long. Its long leaves are typical of Mediterranean plant flora.

White oleander flowersUse 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.

Read also:

Smart tip about oleander

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.

Images: 123RF: 13smile; own work: Rosalyn & Gaspard Lorthiois; Pixabay: M W
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  • MrsRasher wrote on 12 October 2020 at 12 h 58 min

    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

    • Gaspard wrote on 13 October 2020 at 9 h 11 min

      Oleander does grow prolifically when in the proper growing environment. And the blooms are very beautiful!