The latest course on planting techniques and methods of Dahlia

Dahlia is known as one of the most famous flowers in the world, mainly because of its long flowering period, large diameter and many flowers. in the north, it blossoms continuously at suitable temperature from May to mid-November, and blossoms most after autumn. it is very suitable for flower beds, flower paths or pre-court cluster planting, and dwarf varieties can be used as potted plants. Let's take a look at the planting techniques of Dahlia.

Growth habits of Dahlia

1. Lighting: dahlias like semi-shade, too strong sunlight affects flowering, the light time is generally 10-12 hours, when cultivating seedlings, it is necessary to avoid direct sunlight.

2. Temperature: Dahlia likes cool climate. It blossoms the largest, brightest and most prosperous in late September, but it is not resistant to frost, and the stems and leaves wither immediately after frost. During the growing period, the temperature is not strict, 8-35 ℃ can grow, 15-25 ℃ is suitable.

3. Moisture: Dahlia is not resistant to drought and waterlogging. In general, potted plants are watered when the soil is dry, so that they can see wet and dry, and can be drained in rainy days (the ground does not have to be watered frequently).

4. Soil: Dahlia is suitable to be cultivated in fertile sandy soil with loose soil and good drainage.

Split-root propagation of Dahlia

1. Time: the root-splitting propagation of Dahlia is usually between March and April in spring.

2. Sprouting: Dahlia has buds only in the root neck, so each divided root must have a budded root neck, no root neck or no bud point on the root neck can not sprout, can not be planted. If the germination point on the root neck is not obvious or difficult to identify, it can be accelerated in early spring, the roots are arranged at a dense distance in the hotbed, then the soil is obstructed, watered, given a certain temperature, and then divided after budding, each ramet has at least one bud.

3. Planting: take out the stored root, cut off each root and the bud attached to the root neck (the cut is coated with plant ash for antiseptic), and plant separately.

4. Advantages: ramet propagation is simple and easy, the survival rate is high, the plant is strong, but the propagation coefficient is not as high as the cutting method.

Cutting propagation of Dahlia

1. Land selection and land preparation: select fields with deep tillage layer, loose and fertile land, flat terrain and good drainage. Before deep ploughing, 125 kg of superphosphate per mu is applied as base fertilizer, plus 50% of sub-farmers 0.5 kg, soil disinfection, soil depth of about 15 cm, and then rake flat, do high or flat border width of 2 meters, ditch depth of 20 cm, open internal and external "three ditches" to facilitate drainage.

2. Cutting method: usually from June to August, lateral buds grow to 15 to 20 cm, combined with lateral buds cut along with sowing. The cuttings need 3 buds, leave the upper 2 buds, cut the third buds to the base of the leaves, insert the second buds into the soil, water them thoroughly, and use 50% shade net for double shade. Water one in the morning and one in the evening on a sunny day, watering continuously for half a month, and the soil moisture is kept at 90% for 3 weeks. The survival rate is very high, and it can blossom in the autumn of that year.

3. Post-cutting management: after the cuttage survived, the saturated leaching solution of compound fertilizer was applied once before and after flowering, and 400 ml mother solution was added to each back sprayer (about 12.5 kg) for extra-root topdressing. Dahlia should not be ploughed deep after rooting, so as not to damage the root tuber and prevent grass damage. Because the plant is succulent and soft, it is necessary to stand up so as not to break the stems and leaves. When the seedlings of small flowers are 15 cm high, they are topped to make the plants stout and blossom. After the flowers are taken off in time, the flowering period can be prolonged.

Seed propagation of Dahlia

1. Container selection: choose a seedling plate with a length of 50 cm, a width of 20 cm and a height of 5 cm, rinse with clean water first, and then disinfect it with 0.2% chloronitrobenzene.

2. Substrate configuration: select fine, uniform, stone-free, pollution-free, nutrient-rich and pest-free soil. It is suitable for the soil with good drainage and light saline-alkali. The selected sowing substrate is garden soil and peat, which is generally made of garden soil, humus soil and river sand, with a proportion of 2:2:1, and sterilized with 2% pentachloronitrobenzene or high temperature disinfection.

3. Sowing time: wash the sterilized seedling tray with clean water before sowing, sow immediately after water osmosis, sow in the hotbed in mid or late March, flower bed varieties are sown in late April, the seeds are all scattered on the soil surface, and the large seeds are covered with moist fine soil after sowing, and the thickness is 3 times of the seed diameter.

4. Film mulching: bamboo pole is used to cover agricultural film after sowing, leaving gaps for ventilation, which is helpful to increase soil temperature, reduce moisture, maintain soil moisture and reduce soil consolidation, so as to maintain the temperature and humidity needed for seed germination. After sowing, the seeds can germinate after about 7 days after sowing, and the soil moisture should be maintained frequently. When the seedlings grow to 4cm, the seedlings should be watered thoroughly, placed in the shade for 3-4 days, and then moved to strong light. Pay attention to timely watering to maintain soil moisture.

5. Management after sowing: watering according to soil moisture. Keep the soil dry and moist when the soil surface is slightly dry, keep it moist by immersion method. The optimum temperature for seed germination is 19: 21 ℃. It is often ventilated after sowing, which is conducive to seed germination. Dahlia seed germination needs proper shade, after the emergence of neat seedlings, gradually remove the film, and move the seedlings to a sunny place. 180 °turning box every 2-3 days is beneficial to the upright growth of seedlings.