How to grow Osmanthus fragrans 'Semperflorens'? Detailed growing methods and precautions

Osmanthus fragrans 'Semperflorens' originated in the Mediterranean region, and has been widely introduced and planted in southern China, so it is suited to growing in warm, humid places. It has high ornamental value, and as a timber it also has considerable practical value.

So, how should Osmanthus fragrans 'Semperflorens' be grown? What growing methods are there, and what needs attention?

How to grow Osmanthus fragrans 'Semperflorens'

1. It is suited to growing in warm, humid places with plenty of sunlight. The soil used should be fertile, loose, slightly acidic and well drained. Osmanthus fragrans 'Semperflorens' is fairly drought-tolerant and cold-tolerant, with an optimum growing temperature of 20—30℃; in winter, if there is no exceptionally severe cold wave, it can generally overwinter outdoors.

2. Osmanthus fragrans 'Semperflorens' likes warmth, and generally grows well at 18℃ to 25℃, flowering abundantly with a delicate fragrance. If the temperature falls below 15℃, it enters a semi-dormant state and flowers less. It can survive winter at 3℃ to 5℃, but will not flower.

Growing methods and precautions for Osmanthus fragrans 'Semperflorens'

1. Choose the pot and soil well

Osmanthus likes slightly acidic, well-drained, fertile sandy loam. In strongly acidic soil, osmanthus grows slowly, with yellowing and withered leaves and few branches; in soil with a pH of 3-4, grafted two-year-old seedlings produce only 2-3 branches in that year, with branch length of only 6cm, compared with soil at pH 6, where they produce 2 times more branches and branches 1-2 times longer.

In alkaline soil, withered and yellowed leaves appear within two to three months, and the plant gradually dies.

2. Abundant flowering depends on fertilizer

1. Osmanthus likes pig manure. It can be mixed into the potting soil, or applied to the bottom of the pot after being composted and dried.

2. The amount of fertilizer applied should be based on 1/4 of the pot height; the fertilizer should be covered with a layer of soil about 1 cun-2 cun thick, then Osmanthus fragrans 'Semperflorens' can be planted, and no further fertilizing is needed within a year.

3. In cities where pig manure is unavailable, donkey, horse or mule hooves can be soaked to make a liquid; water once when new growth begins in spring, then from before August, water once every 7-10 days. You can also use sauce residue, cooked soybeans, or cooked raw peanuts, ground into powder, and bury it in the potting soil in holes dug around the roots.

3. Watering should be appropriate

1. When watering osmanthus, master the rule of two less and one more.

2. Water less for plants repotted before new shoots appear, water less on cloudy and rainy days, and water more on dry days in summer and autumn.

3. After repotting and watering thoroughly, maintain a moisture content of about 50% regularly; during the dog days (July-September), the soil moisture content should be about 60%.

4. At the same time, air humidity must also be maintained. Place the osmanthus in a shaded spot and spray water on the leaves once each morning and evening. Or place a water-filled fish tank or small basin nearby, and put the osmanthus in the open air to receive night dew and increase humidity, keeping the leaves fresh.

4. Flowering period control

1. The formation and differentiation of flower buds in Osmanthus fragrans 'Semperflorens', through to flowering, requires a high temperature -- low temperature — high temperature process.

2. Differentiation begins at a high temperature of about 30℃, with flower buds forming in 25-31 days; after 3-5 days of low-temperature dormancy at about 15℃, the flower buds begin to sprout.

3. After the flower buds sprout, at a high temperature above 25'C, they quickly bloom.

5. Shaping

1. Osmanthus is mainly valued for its foliage, form and flowers. The flowers are small but fragrant; the main appeal is the beauty of the leaves and form.

2. The shaping should express an air of prosperity and wealth, solemnity, and elegant purity.

3. Ligustrum (privet) can be used as rootstock; first move large-leaved privet into a flowerpot, and from the summer solstice to the autumn equinox, approach grafting can be used throughout this period, that is, grafting the osmanthus branch onto the privet branch by approach, removing the top of the privet branch.

4. After it survives, cut the osmanthus from the parent plant, forming a new osmanthus plant; the survival rate can generally reach 100%.

Rootstock grafting methods for Osmanthus fragrans 'Semperflorens'

1. The main ones are privet, white ash, lilac, and fringetree.

2. The disadvantage of privet as rootstock is that its root system is too developed, making it unsuitable for potting, and it flowers late.

3. The disadvantage of white ash as rootstock is its short lifespan, and it easily drops its leaves in winter and flowers relatively little.

4. With lilac as rootstock, the trunk is thick at the top and thin at the bottom, making the tree shape top-heavy.

5. Fringetree as rootstock has good compatibility, drought and cold resistance, strong adaptability, and a long lifespan, with trees living more than a hundred years. Therefore, the most suitable rootstock for potted osmanthus grafting propagation is fringetree.

Common diseases of Osmanthus fragrans 'Semperflorens'

1. Osmanthus fragrans 'Semperflorens' leaf spot disease: the pathogen mostly invades from the leaf margin and leaf tip, occurring at the leaf margin and leaf tip.

2. Osmanthus fragrans 'Semperflorens' anthracnose: this disease infects osmanthus leaves.

Osmanthus fragrans 'Semperflorens' has a certain resistance to harmful gases such as hydrogen fluoride and sulfur dioxide, and can reduce the degree of environmental pollution. Planted in public places or home courtyards, it can play a good role in greening, beautifying, perfuming and purifying, so it is widely planted in flower gardens and similar places.