How to Grow Osteospermum? The Latest Cultivation Techniques and Methods Tutorial

Osteospermum (African daisy) is a perennial herbaceous flowering plant of the Asteraceae family, native to South Africa and introduced into China from abroad in recent years, grown as an annual or biennial herbaceous flower; whether used as a potted flower for desktop display or for early-spring landscaping, it is a rare and valuable floral material. Below, let us take a look together at the cultivation techniques of Osteospermum!

Growth Habits of Osteospermum

Osteospermum loves sunlight and is moderately cold-tolerant, able to endure low temperatures of -3°C to -5°C. It is drought-tolerant and prefers loose, fertile, sandy loam soil, performing even better in moist, well-ventilated environments. It has strong branching ability and does not require pinching. It blooms early and has a long flowering period; low temperatures favor flower bud formation and blooming, and in regions with a mild climate it can grow year-round.

Cuttage Propagation of Osteospermum

1. Cutting method: For cuttage propagation, the cuttings need to be planted in the rooting seedbed within 12 to 24 hours after being taken. If time does not allow, they need to be temporarily stored at a temperature of 7°C to 10°C. A higher substrate temperature (20°C to 23°C) is beneficial for rooting of the cuttings; after rooting, the temperature can be lowered. In addition, dipping in rooting hormone can stimulate earlier rooting and improve the uniformity of rooting.

2. Cutting management: In the early stage of cuttage (within 3 to 5 days), the misting system needs to be kept running for extended periods, taking care to prevent unrooted cuttings from wilting, and reducing the frequency of misting at night. After rooting, fertilizer at a concentration of 75 ppm to 100 ppm can be applied, gradually increasing the fertilizer concentration to 150 ppm as the root system grows, while keeping the substrate moderately moist and avoiding over-saturation. This not only prevents leaf yellowing caused by iron loss but also reduces the occurrence of diseases.

Cultivation Techniques of Osteospermum

1. Sowing method

[Time] November to January.

[Plug tray] According to the purpose of production, choose 72, 128 or 200 plug trays.

[Method] Dibbling, one seed per cell.

[Substrate] Mix peat : vermiculite = 3:1, pH 6.2-6.5; too low will cause poisoning by certain metal elements (such as iron, sodium, etc.). Soak the plug tray thoroughly the day before sowing and set aside.

[Covering material] Cover the seeds with medium-grade vermiculite, which facilitates air and water permeability. After sowing, to ensure the temperature and humidity needed for germination, plastic film can be used to cover the plug tray.

2. Germination stage, phase 1: From sowing to the emergence of cotyledons, about 6-8 days. At this point the plastic film can be removed.

[Substrate] Substrate moisture content 80%±5%.

[Humidity] 70%-80%.

[Temperature] 20°C-25°C.

3. Germination stage, phase 2: From the appearance of cotyledons to the cotyledons fully grown, completing the germination process.

[Temperature] Lower the temperature to 18°C-25°C.

[Substrate] Keep moist (moisture content about 80%); when necessary, water can be sprayed onto the seedling tray in the form of mist.

[Fertilizer] Apply 50-75 ppm (EC value 0.8) nitrogen, phosphorus and potassium compound fertilizer.

[Light] No more than 25000 lux; supplemental lighting can make the plants bloom earlier.

4. Germination stage, phase 3: From the appearance of the first true leaf until the plug seedlings reach standard specifications (more than 4 true leaves, root system filling the cell).

[Temperature] 18°C-20°C.

[Moisture] Moderate moisture content, avoiding the substrate being too dry or too wet.

[Fertilizer] Apply 150 ppm nitrogen-phosphorus-potassium compound fertilizer once every 3-4 days (EC value 1.0-1.2). Ammonium nitrogen fertilizer favors the growth of above-ground stems and leaves, while nitrate nitrogen fertilizer favors root development.

[Light] Same as phase 2.

[Control] Under normal circumstances, Osteospermum plants grow relatively robustly and rarely become leggy. To prevent some varieties from growing too tall, B9 or PP333 can be used at the end of phase 3 to control plant height.

5. Germination stage, phase 4: The transitional growth stage between the end of plug seedling cultivation and potting up or selling of the plug seedlings.

[Temperature] Lower the growing temperature to 17°C-18°C. From the beginning of this period until before flowering, the plants must go through a low-temperature phase of 5°C-8°C at night, which is beneficial for the plants to smoothly carry out flower bud differentiation and blooming.

[Water and fertilizer] Control moisture and excessive ammonium nitrogen fertilizer to avoid leggy growth of the plants. Keep the substrate on the dry side, strengthen ventilation and lighting, and enhance the resistance of the plants.

6. Management after potting up: Generally, the plug seedling period for Osteospermum is 10-12 weeks. After the plug seedling period ends, potting up should be done promptly, otherwise it will cause the flowering period to come earlier.

[Substrate] Mix peat : vermiculite : garden soil = 1:1:1, pH 6.2-6.5.

[Temperature] 18°C-23°C during the day, 10°C-18°C at night. Too high a temperature will make the flowers smaller, and too low a temperature may cause leaf yellowing in some types.

[Moisture] Keep the substrate moisture alternating between dry and wet, but do not let the substrate become too dry or too wet; excessively high humidity will lead to leggy growth of the plants or trigger diseases.

[Fertilizer] Apply 150-200 ppm nitrogen-phosphorus-potassium compound fertilizer (EC 1.2-1.4).

7. Pests, diseases and their control

[Pests] Osteospermum cultivation and management is simple, with few pests and diseases. The common pest is aphids, which can be controlled by spraying the plants with 80% dichlorvos emulsifiable concentrate at 800-1000 times dilution or Yibianjing at 1000 times dilution.

[Diseases] The first common disease is root rot, mostly caused by overwatering. It can be prevented by properly controlling water and keeping the substrate slightly moist to on the dry side. Once root damage is found, repot promptly and replace the substrate. The second is leaf yellowing; the causes and control measures for leaf yellowing are as follows: ① Yellowing mainly affects young leaves and often shows spots. The cause is too low a substrate pH, resulting in iron poisoning; the substrate pH can be adjusted by watering with an appropriate concentration of lime water. ② During the seedling period, the temperature is too low; the night temperature can be appropriately raised. ③ Insufficient nitrogen fertilizer application; the amount of nitrogen fertilizer can be appropriately increased.