A Detailed Guide to Osmanthus Tree Cultivation Methods and Precautions

When the osmanthus blooms, its rich fragrance carries far. Its scent combines both freshness and richness: the fresh note can cleanse, the rich note can travel afar, which is why it earns the laudatory name “fragrance within nine li”. It is also a symbol of nobility, chastity, honor, friendliness and good fortune. So, what are the cultivation methods for osmanthus trees? What precautions are there?

I. What are the cultivation methods for osmanthus trees?

1. Choosing a site

Spring or autumn should be chosen, and planting on an overcast or rainy day is best. Choose a spot that is well ventilated, well drained and warm; either full sun or partial shade will do. When transplanting, a good root ball must be formed to ensure the survival rate. The planting soil should be on the acidic side; alkaline soil is to be avoided.

2. Sowing

Osmanthus fruit usually ripens from April to May. After harvesting, sprinkle with water and pile up to ferment, remove the flesh, place in a cool spot so the seeds air-dry naturally, then store mixed with sand. After sand storage, they can be sown in autumn or spring. Before sowing, prepare the ground well and apply plenty of base fertilizer; they can also be sown in an indoor seedbed. When sowing, place the seed with the hilum facing sideways, so as to prevent the radicle and young stem from curving, which would affect the growth of the seedlings later on.

3. Watering and fertilizing

Before planting in the ground, mix plant ash and organic fertilizer into the planting hole first, and after planting give one thorough watering. Keep the soil moist before new shoots emerge, and be sure not to water with fertilizer solution. Generally apply a nitrogen fertilizer once in spring and a phosphorus and potassium fertilizer once in summer, so the flowers are abundant and the foliage lush; before winter sets in, apply an organic overwintering fertilizer once, mainly consisting of rotted cake fertilizer and barnyard manure. Avoid strong fertilizer, and especially avoid human excrement and urine.

4. Shaping and pruning

This depends on the tree: set the main framework according to the tree's form, then remove the other root suckers, overly dense branches, water sprouts, crossing branches and diseased or weak branches, so as to improve ventilation and light penetration. For trees that are strong on top and weak below, the upper branches can be cut back by 1/3 to make the overall tree vigor strong; at the same time, apply a wound healing and anti-decay membrane to the pruning cuts to protect the wounds.

5. Pest and disease control

Osmanthus brown spot, osmanthus blight and osmanthus anthracnose are common leaf diseases of osmanthus. These diseases can cause early leaf drop in osmanthus, weaken the plant's growth vigor, and reduce both the flower yield and the ornamental value of osmanthus.

II. What precautions are there for cultivating osmanthus trees?

1. Light and temperature

In areas south of the Yellow River basin it can be grown outdoors and overwintered there. Potted plants should be moved indoors in winter and placed in a sunny spot so they receive plenty of direct sunlight, with the room temperature kept above 5°C but not above 10°C. After budding the following April, move them outdoors, first placing them in a sheltered, sunny spot for care, and once growth has stabilized gradually move them to a ventilated, sunny or partially shaded environment, then carry out normal care. Insufficient light during the growing period affects flower bud differentiation.

2. Transplanting at the right time

One-year-old osmanthus seedlings from seed reach 20-30 cm in height, and are transplanted in early spring of the following year. Two-year-old seedlings are about 60 cm tall, and when three-year-old seedlings reach about 1 m in height, they need to be transplanted again. For use as a shade tree in a courtyard or a street tree, they generally need to be grown for 8-10 years, to a height of 2-3 m and a diameter of 8-10 cm, before they are easy to care for and manage after planting.

Osmanthus trees not only have a graceful shape and stay evergreen all year round, their flowers also have a fragrance that delights the heart. Why not plant one or two in your own yard?