The Latest Dahlia Planting Techniques and Methods Tutorial

The reason dahlia is called one of the world's famous flowers is mainly because of its long flowering period, large flower diameter, and numerous blooms. In northern regions, the flowering period runs from May to mid-November, and under suitable temperature conditions it can bloom continuously year-round, with the most abundant blooming after autumn. It is very suitable for mass planting in flower beds, along flower borders, or in front of courtyards, and dwarf varieties can be grown as potted plants. Now let's take a look at dahlia planting techniques!

Dahlia Growth Habits

1. Light: Dahlia prefers partial shade; too strong sunlight affects flowering. The light duration is generally 10 to 12 hours, and direct sunlight should be avoided when cultivating seedlings.

2. Temperature: Dahlia likes a cool climate. It blooms largest, most brilliantly, and most abundantly in late September, but it is not frost-tolerant, and the stems and leaves wither immediately after frost. During the growing period, it is not strict about temperature and can grow at 8 to 35°C, with 15 to 25°C being ideal.

3. Water: Dahlia is not tolerant of drought or waterlogging. Generally, for potted plants, water thoroughly when the soil looks dry, following the principle of alternating wet and dry. On rainy days, the pot can be tipped to drain water (in-ground plants do not need frequent watering).

4. Soil: Dahlia is suitable for cultivation in loose, well-drained, fertile sandy soil.

Dahlia Root Division Propagation

1. Time: Dahlia root division propagation is usually done between March and April in spring.

2. Sprouting: Dahlia only has buds on the root crown, so each divided tuberous root must have a bud-bearing root crown. Tuberous roots without a root crown or without bud points on the root crown will not sprout and cannot be planted. If the sprouting points on the root crown are not obvious or difficult to identify, sprouting can be forced in early spring in advance. Arrange the root clusters relatively close together in a hotbed, then mound soil over them, water, and provide a certain temperature. After sprouting, divide them again, with each division having at least one bud.

3. Planting: Take out the stored tuberous roots and cut off each tuberous root together with the buds attached to the root crown (coat the cut surface with plant ash to prevent rot), then plant separately.

4. Advantages: Division propagation is simple and easy, with a high survival rate and robust plants, but the propagation coefficient is not as high as that of the cutting method.

Dahlia Cutting Propagation

1. Site selection and land preparation: Choose a field with deep arable soil, loose and fertile soil, flat terrain, and good drainage. Before deep plowing, apply 125 kg of superphosphate per mu as base fertilizer, plus 0.5 kg of 50% diazinon for soil disinfection. Plow the soil about 15 cm deep, then level and rake it, and make raised beds or flat beds 2 m wide with 20 cm deep furrows, and open the inner and outer “three ditches” well to facilitate drainage.

2. Cutting method: Usually from June to August, when the side shoots grow to 15 to 20 cm, cut and plant them immediately while removing side shoots. The cutting needs 3 buds; keep the upper 2 buds and cut the 3rd bud down to the leaf base and remove the leaf. Insert it into the soil as deep as the second bud, water thoroughly, set up supports, and use double-layer 50% shade netting for shading. On sunny days, water once in the morning and once in the evening, watering continuously for half a month, keeping soil moisture at 90%. Roots form after 3 weeks, with a very high survival rate, and they can bloom in autumn of the same year.

3. Management after cutting: After the cuttings survive, combine intertillage and weeding with one application of saturated compound fertilizer extract before flowering and one after flowering. For each backpack sprayer (about 12.5 kg), add 400 ml of the mother solution for foliar topdressing. After dahlia roots form, deep intertillage is not advisable, so as to avoid damaging the tuberous roots and to prevent weed problems. Because the plants are juicy and soft, supports must be set up to prevent the stems and leaves from breaking. For small-flowered varieties, pinch the tips when the seedlings are 15 cm tall to make the plants short and sturdy with more flowers. Remove spent flowers promptly to extend the flowering period.

Dahlia Seed Propagation

1. Container selection: Choose a seedling tray 50 cm long, 20 cm wide, and 5 cm high. First rinse it with clean water, then disinfect it with 0.2% chlorine-free nitrobenzene.

2. Substrate preparation: Choose fine, uniform, stone-free, pollution-free soil rich in nutrients and free of pests and diseases. Soil with good drainage and low salinity and alkalinity is suitable. The sowing substrate used is garden soil and peat; it is generally made by mixing garden soil, humus soil, and river sand in a ratio of 2:2:1, and is disinfected with 2% quintozene or by high temperature.

3. Sowing time: Before sowing, wash the disinfected seedling tray clean with water, and sow immediately after the water seeps in. For hotbed sowing, sow in mid-to-late March; for flower bed varieties, sow outdoors in late April. The seeds are all scattered on the soil surface; after sowing large seeds, cover them with moist fine soil to a thickness 3 times the seed diameter.

4. Film covering: After sowing, prop up agricultural film with bamboo poles, leaving gaps for ventilation, which helps raise soil temperature, reduce moisture loss, maintain soil humidity, and reduce soil compaction, thus maintaining the temperature and humidity needed for seed germination. After sowing, place at 20 to 25°C; after about 7 days, the seeds will begin to sprout. Always maintain soil moisture. When the seedlings grow to 4 to 5 cm, prick out the seedlings, water thoroughly, place in a shaded spot for 3 to 4 days, then move to strong light, and water timely to maintain soil moisture.

5. Management after sowing: Water according to soil moisture conditions. Keep the soil alternately dry and moist; when the soil surface is slightly dry, use the soaking method to keep it moist. The suitable temperature for seed germination is 19 to 21°C. Ventilate frequently after sowing, which helps seed germination. Dahlia seed germination requires appropriate shading. After the seedlings emerge evenly, gradually remove the film and move the seedlings to a place with sufficient sunlight. Rotate the tray 180° every 2-3 days, which helps the seedlings grow upright.