When is the best time to sow Lagerstroemia indica seeds?

Campanula is native to the Mediterranean coast and likes cool and humid semi-cool environment. It should be cultivated in soil with rich humus and good drainage and air permeability. The growth temperature is 15℃ to 20℃, and it is best to keep it above 10℃ in winter, and give enough light and properly control watering to make the basin soil slightly dry and avoid cold wind blowing, otherwise it will cause freezing damage due to low temperature and low humidity. During the growing season, the soil in the basin should be kept moist. Excessive humidity is bad for the growth of plants. When the environment is dry, you can often spray plants to increase air humidity. Apply decomposed dilute liquid fertilizer once a month and stop applying fertilizer in winter and summer. When the temperature is high in summer, move the plants to a ventilated and cool place for maintenance, and shade them appropriately to prevent them from being exposed to the hot sun. When the weather is hot and sultry, the leaves will turn yellow and fall off, or even the whole plant will wither. Therefore, we should try to avoid this unfavorable environment in cultivation. Propagation techniques are mainly sowing and propagation, and can also be divided into plants or cuttings. Capsule is formed after flowering, and the first fruit has many seeds. The seeds are small, so they can be dried and stored. In spring, late winter or early spring, it should be planted in a plastic greenhouse with heat preservation, so as to facilitate the alternation of high temperature and summer heat during flowering. According to the requirements of small seeds, the soil preparation should be meticulous, subsoiling for more than 2 times, leveling the ground, pouring enough water, and then sowing seeds evenly. After sowing, do not cover the soil or screen the fine soil with a thin cover. Spraying water with a sprayer at seedling stage, and thinning and replenishing seedlings according to the growth of seedlings. You can also sow in a warm sand table and apply compound fertilizer immediately after emergence. When the seedling height is about 10 cm, it should be transplanted to the nursery or planted permanently in the upper pot. The suitable row spacing for nursery planting is 20cm× 40cm. After transplanting, the roots should be watered and managed as usual. You can also sow in autumn. Generally, the seedlings sown in the autumn of that year need to be cultivated until the spring and summer of the following year to bloom. Plants divide more than in autumn. After one winter's cultivation, they can blossom in the second year. Cutting is not only picking new buds sprouting at the base in spring, inserting them into wet sand beds, spraying water frequently, and transplanting after rooting. Plug seedling raising period 1: The seeds can germinate after sowing in radicle germination period 14 ~ 18 days, with daily temperature of 20 ~ 22℃ and night temperature of 16℃. The soluble salt content in the matrix is kept low, and the pH value is kept between 5.5 and 6.2. Seeds do not need to be covered after sowing. Keep the soil slightly wet, but not too wet. Avoid direct sunlight after sowing and need proper shading. Alternating temperature changes will stimulate seed germination, and supplementary light after germination can promote plant growth and flowering. The second stage: the cotyledon emergence growth stage starts from this stage, and the soil moisture should be reduced appropriately, but it should not be too dry. The EC value of culture medium should not be higher than 0.5. Fertilizer can be sprayed, and 50ppm balanced nitrogen fertilizer is suitable. The third and fourth stages: true leaf growth, development and seedling hardening. In these two stages, the fertilizer concentration can be increased to 150ppm to 200ppm. Cultivation management 1. Transplanting: 6-8 weeks after germination, 9- 1 1 cm flowerpot can be transplanted. Don't plant too deep when transplanting plants. 2. Substrate: The cultivation substrate should be well drained, with clay content of 20% to 30%, and 1 to 1.5 kg of fully balanced fertilizer should be applied per cubic meter of substrate. The matrix should contain iron chelates and micronutrients, and the pH value should be 5.5 to 6.2. 3. Illumination: It is a long-day plant. Cultivation method 1: In spring, plants begin to grow for 2 weeks under short sunshine, and at this time, light needs to be supplemented 10 ~ 12 hours, with 20 ~ 30 watts per square meter. When the plant grows to the ideal height, the sunshine time can be extended to 16 ~ 18 hours in order to promote the flowering of the plant. You need to cut off the light supply at night. Cultivation method 2: First of all, in the first three weeks of cultivation, in order to make the plants grow, the plants should be placed under the condition of short sunshine and supplemented with light 10 ~ 12 hours, with 20 ~ 30 watts per square meter. When the plant grows to the ideal height, the sunshine time can be extended to 16 to 18 hours in order to make the plant blossom. You need to cut off the light supply at night. 4. Temperature: The suitable temperature for fertility is 65438 03℃ to 65438 08℃. Under frost-free conditions in winter, the indoor or outdoor temperature can be kept at 3℃ to 5℃. Outdoor cultivation needs covering. In spring, plants begin to grow at the temperature of 65438 05℃ to 65438 08℃ for 5 to 9 weeks. At the low temperature of 65438 03℃, the culture time will be extended to 65438 05℃. Plants don't need to go through vernalization. 5. Fertilizer: This plant needs a proper amount of fertilizer. Nitrogen fertilizer and balanced potassium fertilizer (n: K2O ratio 1: 1.5) are applied alternately every week. Excessive ammonium and nitrogen content should be avoided. Don't fertilize after mid-September. To prevent magnesium and iron deficiency, 0.025% magnesium sulfide 1 ~ 2 times and iron chelate 1 ~ 2 times can be sprayed respectively. 6. Cultivation tips: outdoor potted plants should be sprayed with fungicides to prevent the propagation of botrytis cinerea, Rhizoctonia solani and pythium.