Oleander plant care and wintering guidance

Gardening guidance for oleander (Nerium oleander) focuses on seasonal transitions from late summer through winter.

In September, care involves selecting hardy varieties like the ‘Villa Romaine’ cultivar, which can withstand temperatures between −12 and −15 °C. For potted plants, it is recommended to use containers with a diameter of at least 40 to 50 cm and provide 6 to 8 hours of direct sunlight.

As winter approaches, plants should be moved to sheltered areas or indoors by mid-November. Ideal overwintering conditions include cool, bright spaces with temperatures between 2 and 10 degrees Celsius; keeping plants in warm rooms is discouraged as it may prevent necessary dormancy. To prevent root rot, watering should be gradually reduced in late summer, leaving the soil only slightly moist during winter. Additionally, gardeners are advised not to prune faded flowers in autumn to protect new flower buds.

In October, management of water saturation becomes critical to prevent root asphyxiation caused by excessive rain. If saturation occurs, action should be taken within 48 to 72 hours to avoid root necrosis, where roots turn “black and soft due to a lack of oxygen.” Recommended interventions include emptying saucers and cache-pots and elevating containers to facilitate drainage.

To rejuvenate older, sparse plants, gardeners can utilize the ‘rule of thirds’ pruning method. This involves replacing one-third of the oldest, thickest stems by cutting them close to the ground to encourage new growth from the base and restore a bushy appearance.