How to care for osmanthus trees in winter so they survive the cold safely

Osmanthus is one of China's ten traditional flowers and is planted in many parts of the country. It is not suited to sub-zero Celsius environments, so it can be described as a plant that fears freezing. In southern China, osmanthus is mostly grown in the open ground and generally survives the winter safely; only in some severely cold areas of the north do you need to pay attention to frost protection when growing it. Below, Huazhiwu Baike introduces the methods for protecting northern osmanthus from the cold and helping it overwinter:

Rows of potted osmanthus in a courtyard

1. Protecting potted osmanthus trees from freezing is fairly simple: just move the pots indoors in late autumn (usually after Frost's Descent and before the Start of Winter), or place them on a sunny balcony. Make sure there is ventilation to avoid pests and diseases. If the plant enters dormancy, keep the potting soil slightly moist, which will help it bloom the following year.

In northern regions, after moving potted osmanthus indoors in late October or early November, place it in a spot with ample light (the indoor temperature should be kept at 3-5°C), and keep the relative humidity between 60% and 80%. Indoor light conditions in winter should be somewhat better (especially before the buds begin to swell in early spring, when even more sunlight is needed). Indoor temperatures in winter should not be too high, and humidity should not be too great either; otherwise the osmanthus will sprout prematurely indoors, which is bad for its growth after being moved outside. In early April of the following year (after Qingming), the potted osmanthus can be moved outside in good time. After moving it out, first place it in a sheltered, sunny spot for 1 week so it gradually adapts to the outdoor conditions, then spread the pots out as needed.

Open-ground osmanthus trees

2. For osmanthus trees grown in the open ground, seedlings are more afraid of freezing than mature trees. You can build a windbreak barrier or cover them with transparent plastic film. For mature osmanthus trees, you can tie straw and plastic film around the trunk for cold protection.

In the north, open-ground osmanthus can tolerate a minimum temperature of -5°C to -8°C; beyond this limit, the osmanthus will suffer frost damage to varying degrees. Therefore, when planting osmanthus in the open ground in the north, choose a sunny, sheltered spot and add artificial winter protection measures so it can overwinter safely. After the Winter Solstice each year, you can manually tie the trunk with straw rope, or wrap the trunk with other insulating materials, which can prevent ordinary frost damage. Before the soil freezes, cultivate the soil around the root collar along with hoeing, and then you can also wrap the osmanthus canopy with light-transmitting plastic film, taking care to leave ventilation holes, so the osmanthus safely gets through the severe winter.

Wrapping the trunk and mounding soil around the roots for frost protection

[Tips] Although the above from Huazhiwu Baike mainly covers methods for protecting northern osmanthus trees from the cold and helping them overwinter, friends in southern regions who grow osmanthus trees can also provide cold protection if they wish; under normal circumstances there is simply no need, and doing simple winter care and management is enough.