Zinnia Planting Methods and Care Tips
Zinnia is a famous ornamental plant, also known as zinnia elegans, step-by-step high, fireball flower, opposite-leaf chrysanthemum, etc. It is an annual herbaceous plant of the genus Zinnia in the Asteraceae family, native to Mexico. It has single-petaled, double-petaled, curled-leaf, crinkled-leaf and various garden varieties of different colors, and is widely cultivated throughout China, sometimes becoming wild. Let's take a look at the planting methods of zinnia below!
Zinnia Propagation Methods
1. Seed propagation: Before sowing, the soil and seeds must undergo strict disinfection treatment to prevent pests and diseases during the growing period. Sowing can be done from early April to late June. For seed disinfection, soak the seeds in 1% potassium permanganate solution for 30 minutes. The substrate is prepared by mixing 2 parts leaf mold, 1 part river sand, 2 parts peat, and 2 parts perlite. Before sowing, moisten the substrate and sow by dibbling. After sowing, cover with a layer of vermiculite. At a temperature of 21-23°C, germination occurs in 3-5 days.
2. Cutting propagation: Zinnia can also be propagated by cuttings, but cutting seedlings are less uniform than seed-grown seedlings. Select lateral buds 10 cm long for cuttings. Roots generally form in 5-7 days. Subsequent cultivation management is the same as for sowing, and the plants can leave the nursery after 30-45 days.
Zinnia Planting Methods
1. Plant shaping: If zinnia is not pinched, the plant will have too few lateral branches and fewer flowers. Proper pinching can promote plant dwarfing and increase flower count. When seedlings grow to 4 leaves, transplant and pinch to encourage lower branching and form a better plant shape. Begin pinching one week after transplanting, keeping 4 pairs of true leaves, and decide whether to pinch again based on plant growth and branching.
2. Water and fertilizer management: At transplanting, apply 2-3 grams of compound fertilizer to the bottom of the pot. After transplanting, drench the roots with 800x diluted Dexon for disinfection. Within 1 week after transplanting, keep the potting soil moist to promote surface root growth. Once roots reach the bottom of the pot, begin topdressing, fertilizing 2-3 times per week, and also apply 1 calcium fertilizer supplement.
3. Timely pinching: Begin pinching 1 week after transplanting. After pinching, spray 1 fungicide treatment and apply 1 heavy fertilizer application. About two weeks after the final pinching, the plant enters the reproductive stage. Gradually increase phosphorus and potassium fertilizers, such as spraying 1000x diluted monopotassium phosphate, to promote more flowers and vivid flower colors, while correspondingly reducing nitrogen fertilizer usage.
4. Temperature and light: Zinnia prefers warmth and sunshine, and is not tolerant of extreme summer heat or severe cold. The optimal growing temperature is 18-20°C during the day and 15-16°C at night. Growth is especially rapid in summer, and full-sun exposure can be used directly. If sunlight is insufficient, the plant tends to become leggy and its resistance is weaker; in addition, flowering will also be affected.
Zinnia Pest and Disease Control
1. White spot disease
[Symptoms] The disease occurs on zinnia leaves. Initially, small dark brown spots appear, which later develop into lesions with dark brown edges and grayish-white centers, 2-4 mm in diameter. It mostly occurs on lower leaves. In severe cases, the leaves curl and wither, and the lesion surface has dark green mold-like growth.
[Control] Strengthen management, apply sufficient fertilizer, cultivate strong seedlings, provide rain protection and shade, enhance greenhouse ventilation, reduce humidity, and promptly remove diseased plant debris. In the early stage of disease, promptly remove diseased leaves, then immediately spray for control. Use 1:0.5:200 Bordeaux mixture plus 0.1% sulfur powder, or 65% zineb wettable powder at 500x, or 75% chlorothalonil wettable powder at 500-800x, or 50% amobam at 800-1000x.
2. Black spot disease
[Symptoms] Small dark brown spots first appear on the leaves, soon expanding into large irregularly shaped spots, 2-10 mm in diameter, reddish-brown. As the spots expand and increase in number, the entire leaf turns brown and dries up. On stems, the disease starts from the base of the petiole and develops longitudinally, forming dark brown elongated streaks. Symptoms on flowers are similar to those on leaves, and soon the petals shrivel and dry up.
[Control] Choose well-drained areas for planting. Planting density should be appropriate. Avoid continuous cropping. Disinfect seeds before sowing. After autumn, collect and destroy diseased leaves, stems, etc. to eliminate the source of infection for the following year. Save seeds from disease-free healthy mother plants. Spray with 50% zineb or mancozeb at 5000x dilution. When spraying, pay special attention to spraying the undersides of leaves evenly.
3. Mosaic disease
[Symptoms] It occurs throughout the country, often causing stunted and degenerated plants. In the early stage, leaves show slight mottling, which later becomes light and dark green mosaic patterns. Symptoms are more obvious on new leaves.
[Control] Eliminating aphids to prevent disease has a certain controlling effect on zinnia mosaic disease. Also pay attention to field sanitation management, eradicate diseased plants to reduce sources of infection.