Overview
Osmanthus delavayi is a small, evergreen shrub that belongs to the Oleaceae family. This plant is native to Western China and is commonly planted in gardens because of its fragrant flowers and unique appearance.
Common Names
Osmanthus delavayi has several common names, including Delavay Osmanthus, Sweet Olive, and Fragrant Tea Olive.
Appearance
Osmanthus delavayi is a small shrub that grows up to 6-10 feet tall. It has dark green, leathery leaves that measure about 2-4 inches in length. The leaves are smooth on top and have small, microscopic hairs on the bottom.
The plant begins to bloom in early spring and produces clusters of small, fragrant, white or pale orange flowers that grow on the edges of its branches. These flowers have a sweet, fruity scent and attract bees and other pollinators.
After the flowers fade, small green fruits appear, which eventually turn black and contain a single seed when they mature in autumn.
Uses
Osmanthus delavayi is commonly used as an ornamental plant in gardens and parks because of its fragrant flowers and attractive appearance. It is also grown commercially for its fragrant essential oil, which is used in perfumes and aromatherapy.
In Chinese traditional medicine, Osmanthus delavayi leaves and flowers are used as a herbal remedy for treating various health problems, including coughs, bronchitis, and asthma.
Furthermore, Osmanthus delavayi is a suitable plant for a hedge or screening plant because of its dense growth habit.
Light Requirements
Osmanthus delavayi prefers growing in partially shaded to full sun areas. It can tolerate some shade but the plant may not bloom as heavily or produce as much fruit.
Temperature Requirements
This plant can tolerate a wide range of temperatures. It can withstand mild to moderate frost, making it an ideal garden plant for those in temperate climates. Additionally, it can grow in areas with high temperatures as long as it is provided with enough shade and water.
Soil Requirements
The plant requires well-drained soil that is rich in organic matter. It requires a pH range between 6.0 and 7.5, and it grows best in moist but well-draining soils. Too much moisture can cause root rot and kill the plant. Add compost, rotted manure, or peat moss to the soil to enrich it before planting.
Cultivation Methods
Osmanthus delavayi is a shrub that thrives in well-draining soil that is rich in organic matter. The plant prefers a slightly acidic to neutral soil pH, preferably within the range of 6.0 to 7.5. The plant's roots need enough room to grow and access nutrients, making it crucial to plant them in a spacious environment.
Watering Needs
Osmanthus delavayi prefers to grow in moist soil but not in wet soil. A consistent watering schedule is preferable in the first year after planting to help the shrub establish its roots. In subsequent years, watering may be less frequent.
Fertilization
Osmanthus delavayi benefits from annual fertilization in the spring season before active growth. For established plants, use half-pound of a balanced slow-release fertilizer, which contains equal percentages of nitrogen (N), phosphorus (P), and potassium (K). Spread a 2-inch layer of organic compost on the base around the plant, followed by the fertilizer, and then water lightly.
Pruning
Osmanthus delavayi produces flowers on old wood, creating a challenge for pruning. Prune after the blooming period to avoid cutting off the next season's flowers. The shrub requires minimal pruning, mainly for shaping or size reduction purposes. Cut back unhealthy or damaged branches to encourage the growth of new, healthy ones.
Propagation of Osmanthus Delavayi
Osmanthus delavayi is a versatile shrub that can be propagated by various methods, including seeds, cuttings, and layering.
Seeds
Propagation using seeds is the most common and simplest method for cultivating Osmanthus delavayi. This method requires ripe seeds collected from the plant during the mid-to-late autumn period. Seeds need to be planted in a well-draining soil mixture and kept moist. Germination is relatively slow, occurring after several weeks.
Cuttings
Cuttings can be taken from new growth in the springtime and should be about 4 inches long while being stripped of the lower leaves. Dip the cutting in a rooting hormone, then plant it in well-draining soil and keep it moist. Cuttings should be kept in a sheltered location with dappled shade to prevent dehydration until roots have formed.
Layering
Layering is a propagation method that involves encouraging a stem to grow roots while it is still attached to the parent plant. The chosen stem should be partially buried instead of being completely pruned. After a few months, the stem should have produced enough roots to allow it to be detached from the mother plant and replanted in a new location.
Disease Management
Osmanthus delavayi is generally resistant to most diseases but can still be susceptible to some fungal diseases such as leaf spot and powdery mildew. To manage these diseases effectively, maintaining good plant hygiene is important. This includes removing fallen leaves and debris around the plant as well as avoiding overhead watering. Fungicides can also be used as a preventative measure or to control symptoms.
Pest Management
Some common pests that can affect Osmanthus delavayi include spider mites, scale insects, and whiteflies. Spider mites and whiteflies can be controlled using insecticidal soaps and oils, whereas scale insects require systemic insecticides. In addition to these pests, Osmanthus delavayi is also susceptible to deer and rabbit damage. Using repellents or fencing off the area can help prevent damage from these larger pests.
