When overwintering orange trees, as with all citrus plants, the principle applies: the warmer the plants are, the more light they need. The flowering of oranges is usually very weak during warm winters.
How should you overwinter an orange tree in winter?
Orange trees should overwinter at 5 °C at night and up to 15 °C during the day. They need enough light, so winter gardens or greenhouses are ideal. Avoid overwintering in the living room and reduce watering and fertilizing during the winter months.
Optimum wintering temperatures for oranges
Oranges are best overwintered at temperatures of around 5 °C at night and up to 15 °C during the day. This corresponds to the climatic conditions existing in the natural location. On sunny days, the temperature can rise to over 20 °C, even in winter. It just shouldn't become a permanent temperature, because then the plants would wake up from their hibernation.
The warmer the brighter
In addition, the available light is the second most important factor: Basically: the warmer, the brighter. This shows why plants that have overwintered in the living room often react in spring by shedding leaves or, in some cases, even by dying branches. Your energy reserves from the summer season are slowly used up towards spring because the light intensity in the living room is not sufficient for photosynthesis.
Light duration not sufficient in winter
In winter gardens integrated into living spaces and bright living rooms, it is often not taken into account that the human eye adapts much better to reduced lighting conditions than an orange leaf. A maximum of eight hours of daylight, filtered through glazing, seems almost like a permanent night to the plants. However, since orange trees are evergreen, they require a certain minimum amount of light to maintain their vital functions, even during cold winters.
Overwintering in the greenhouse or winter garden
For the reasons mentioned, it is not advisable to spend the winter in a heated living room. Greenhouses and winter gardens, which are kept frost-free in winter using thermostat heating, are ideal wintering locations due to the light they provide. On sunny winter days, however, you must ensure that temperatures above 12 °C are avoided through regular ventilation.
Tips & Tricks
In winter you should not fertilize your orange tree, water it only a little and choose a bright, cool and, if possible, frost-free location. Check for pests before putting away and combat them immediately. Cut the plants into shape, harvest the ripe fruits and remove unripe new growth. Unripe fruit may remain on the tree. They simply continue to ripen next year.
