How to grow zinnias? Detailed guide to planting methods and care essentials

For those who pursue a European style, zinnias can be chosen when arranging the home; this plant can bring you a natural atmosphere and make you feel as if you are in a secluded paradise, between heaven and earth. So what are the planting methods for zinnias? Below, you can follow the editor to learn the details.

Zinnia planting methods:

1. Sowing

Seed propagation is suitable for spring sowing, generally carried out in mid-to-late April, with an optimum germination temperature of 15-20°C. Its seeds are photophobic, so after sowing they should be covered with soil, watered, and kept moist; they sprout and emerge in about 1 week. The germination rate is generally around 60%. From Xiaoman to Xiazhi, in combination with pinching (pinch at 4-5 leaves) and pruning, select vigorous branches, cut a 10-15 cm long softwood shoot as a cutting, remove the lower leaves, keep the upper two leaves, insert it into fine river sand, mist frequently, and provide appropriate shade; it will root in about 2 weeks. After the plants survive transplanting, fertilization during the seedling-growing period does not need to be too frequent; generally apply a liquid fertilizer once a month. As the flowering period approaches, more topdressing can be applied, with liquid fertilizer every 5-7 days until the flowers are in full bloom. When the seedlings reach 10 cm tall, keep 2 pairs of leaves and pinch off the growing tip to encourage side branches. When the side branches grow to 2-3 pairs of leaves, keep 2 pairs of leaves and pinch again a second time. Doing this can make the plant bushy and produce abundant flowers. After spring sowing, they can bloom in 70 days. Zinnias bloom at the tips of the branches; when the flowers fade, promptly cut off the spent flowers from the base of the flower stem while leaving 2 pairs of leaves, so as to induce new shoots from the leaf axils at the cut. After pruning, water frequently and apply topdressing 2-3 times, which can extend the flowering date to before the first frost. The first batch of seeds that matures before the rainy season is of better quality and should be harvested in time for seed saving. Seedlings are transplanted into 10-12 cm pots when they have 4-6 leaves.

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 mixed from 2 parts leaf mold, 1 part river sand, 2 parts peat, and 2 parts perlite, and can be disinfected with 0.05% potassium permanganate or 1000-fold formalin. The soil can be treated by high-temperature fumigation to kill pathogens, pests, and weed seeds in it. Before sowing, moisten the substrate and sow in spots. Zinnias are photophobic flower seeds, so after sowing they must be covered with a layer of vermiculite. At 21-23°C, they can germinate in 3-5 days. No light is needed during the germination period. After germination, keep the seedbed at 50%-60% moisture content; it must not be too wet, so as to avoid root rot or damping-off disease.

The sowing time depends on the desired flowering time. Generally, sow in a greenhouse 2-3 months in advance. Direct sowing outdoors should be done after the severe cold of early spring has passed, otherwise the seedlings will develop poorly; if used for autumn flower beds, it is best to sow in summer. Zinnia seeds are photophobic, so after sowing the soil covering should be thick and dense to increase the germination rate.

Carry out in March-April in spring. Each gram contains 120-130 seeds, the optimum germination temperature is 21-25°C, and after sowing they germinate in 7-10 days, with a germination rate of 60%. From sowing to flowering varies by variety, from 45-75 days. Spring sowing is done in March-April; transplant when there are 4-5 leaves, with a plant spacing of 10 cm. Transplant into the field in early June, with a plant and row spacing of 30×30 cm. During the growing period, apply 10-fold diluted human waste urine once every 10 days. They bloom from July to the first frost. Zinnias can also be propagated by summer side-branch cuttings, but because the temperature is too high and there are many showers, attention should be paid to protective shading.

2. Cuttings

After the seedlings grow 1 true leaf, transplant them once for seedling separation. Zinnias have an underdeveloped root system with few lateral roots, so they are generally transplanted and potted when they have 2 true leaves. When transplanting, they should be moved with soil, and the transplanting substrate should be loose, fertile, and well-drained. It can be made from 3 parts pond mud, 1 part leaf mold, and 1 part decomposed manure compost. The planting depth should be 0.5 cm below the cotyledons. After planting, press the soil lightly and water thoroughly. For dwarf varieties, the plant and row spacing is 30 cm, and for tall-stemmed varieties, 50 cm. After transplanting, apply a leaf fertilizer once a month (such as decomposed sauce residue). To promote dwarfing and more branching, you can also spray B9 100-500-fold solution during the seedling stage.

Pinch multiple times. Dwarf zinnias should be pinched multiple times. The first time is at 6 leaves, keeping 4 leaves and pinching the tip, for a total of 2-3 pinches. After each pinching, apply potassium dihydrogen phosphate; especially from budding to flowering, spray 0.2% potassium dihydrogen phosphate once every 5-7 days. Fertilize to prevent disease. After the plants grow steadily, keep the soil moist; in summer, water once in the morning and once in the evening. During the seedling stage, apply 200 mg/L nitrogen fertilizer and organic liquid fertilizer once every 5-7 days. After 2-3 applications, switch to compound fertilizer. In midsummer, apply thin fertilizer, using fertilizer in place of water.

Cutting propagation is generally carried out in June-July. Use side branches of zinnias, cut 10 cm long, insert into a sand bed, and they root 15-20 days after cutting; after 25 days they can be potted. Because cuttings grow unevenly and the operation is troublesome, it is not widely used in practice.

Zinnia care essentials:

Likes light; likes warmth, avoids extreme heat, tolerates early frost; requires fertile and moist soil; on poor, dry soil the flower quality is noticeably reduced.

Temperature. Zinnias like warmth and sun, and are not tolerant of extreme summer heat or severe cold. The optimum growing temperature is 18-20°C during the day and 15-16°C at night. Growth is especially rapid in summer.

Light. Full sun can be used directly, with direct sunlight. If sunlight is insufficient, the plants tend to grow leggy and their resistance is weaker; in addition, flowering will also be affected.

Water. Because the light requirement is high, water evaporates very easily, so appropriate humidity must be maintained frequently; in summer, water once a day.

Planting density. 12-18 plants per square meter. Zinnias like a slightly moist but somewhat dry soil environment and avoid waterlogged conditions. In addition to applying an appropriate amount of chicken manure as base fertilizer when transplanting, during the vigorous growth stage a thin liquid fertilizer should also be applied once a week. It is a crop that likes nitrate nitrogen, so do not apply ammonium nitrogen fertilizers such as ammonium sulfate and ammonium bicarbonate. Zinnias like sufficient sunlight and avoid shaded environments. Keeping the environment ventilated can prevent leggy growth and reduce the occurrence of powdery mildew. Zinnias like warmth and are not cold-tolerant; their optimum growing temperature is 20-30°C. After frost in autumn, the plants gradually die.

Zinnia care essentials during the growing period

Zinnia care during the growing period

When zinnia seedlings have 2-3 true leaves, they need to be transplanted once, and field planting is carried out in mid-to-late May. During field planting, decomposed organic fertilizer should be applied. When zinnias grow to about 15 cm tall, keep the two pairs of leaves at the base and pinch the growing tip, so as to promote axillary bud growth and enable more branching and more flowering. After the flowers fade, promptly cut off the spent flowers to reduce nutrient consumption and favor the next flowering.

Water and fertilizer care for zinnias

Water timely during the seedling stage, but generally it is not suitable to water too much at other times. However, during the overwintering summer period, water frequently to keep the soil moist. Otherwise, the leaves will turn yellow and the flowers will be small, with poor color, and the ornamental value will be greatly reduced. During the entire growth and development period, generally 3 applications of thin fertilizer are sufficient. During the seedling stage, mainly use a mixed fertilizer of chlorine and potassium; during the bud stage, mainly use phosphorus fertilizer; in early September, apply a chlorine, phosphorus, and potassium compound fertilizer once. If too much fertilizer is applied, the plants tend to grow leggy and then lodge.

When cultivating zinnias as cut flowers, tall varieties should be selected, and the seedlings should not be pinched, so that the flowers at the top of the main stem can be used as cut flowers. Because tall varieties are relatively large, their stems and branches break easily in strong wind, so supports should be set up in time. In hot seasons, zinnias grow weakly, flower poorly, and do not set seed. At this time, water frequently and promptly control red spider mites; after the Beginning of Autumn, they can continue to grow and bloom again.

After each flowering, promptly cut off the spent flowers to reduce nutrient consumption and facilitate blooming again. At the same time, apply 1-2 topdressings mainly of phosphorus and potassium fertilizer. Do not plant continuously in the same plot, so as to reduce the occurrence of disease.

Care for potted zinnias

For potted zinnias, dwarf varieties should be selected, and loose, fertile, well-drained sandy loam should be chosen as the growing medium, with direct sowing; at the same time, not only is reasonable watering and fertilizing needed, but also pinching 2-3 times to encourage branching and more flowering. With proper management, one pot of zinnias can bloom 10-20 flowers at the same time.

Zinnia planting methods: How to plant zinnias?

Zinnias have large, brightly colored flowers and a very long flowering period, from June to September, with flowers opening one after another and maintaining vivid colors for a long time, symbolizing everlasting friendship. What is more interesting is that the first flower of a zinnia opens at the top, and then the flowers at the tips of the side branches open higher than the first flower, so it is also called "step by step higher." So what are the key technical points for planting zinnias? Below, the editor will introduce them to everyone.

1. Plant shaping

If zinnias are not pinched, the plants will have too few side branches and too few flowers. Proper pinching can promote dwarfing and increase the number of flowers. When the seedlings grow to 4 leaves, transplant and pinch to encourage lower branches to grow and form a better plant shape. Start pinching one week after transplanting, keep 4 pairs of true leaves, and decide whether to pinch again according to plant growth and branching. During the flowering period, continue to apply phosphorus and potassium fertilizers such as potassium dihydrogen phosphate to promote continuous production of flower heads. After the flowers fade, promptly cut off the withered flower heads to reduce nutrient loss.

2. Water and fertilizer management

When transplanting, apply 2-3 grams of compound fertilizer to the bottom of the pot. After transplanting, drench the roots with 800-fold dexon solution for disinfection. Within 1 week after transplanting, keep the potting soil moist to promote surface root growth. Once the roots reach the bottom of the pot, topdressing can begin, fertilizing 2-3 times a week (apply water fertilizer on sunny days, with concentration controlled within 200 mg/kg; apply granular fertilizer on rainy days at 2-3 grams per pot). A calcium fertilizer can also be applied once as a supplement. Start pinching one week after transplanting; after pinching, spray a fungicide once and apply a heavy fertilizer once. About two weeks after the last pinching, the plants enter the reproductive stage, and phosphorus and potassium fertilizers can be gradually increased, such as spraying 1000-fold potassium dihydrogen phosphate solution, to promote more flowers and brighter flower color, while correspondingly reducing the amount of nitrogen fertilizer. During this period, ensure sufficient watering, and watering in the morning is better than watering in the afternoon; rapid drying of the leaves can prevent disease and prevent leggy growth.

3. Temperature and light

Zinnias like warmth and sun, and are not tolerant of extreme summer heat or severe cold. The optimum growing temperature is 18-20°C during the day and 15-16°C at night. Growth is especially rapid in summer. Full sun can be used directly, with direct sunlight. If sunlight is insufficient, the plants tend to grow leggy and their resistance is weaker; in addition, flowering will also be affected.

4. Planting density

The planting density is 12-18 plants per square meter. Zinnias like a slightly moist but somewhat dry soil environment and avoid waterlogged conditions. In addition to applying an appropriate amount of chicken manure as base fertilizer when transplanting, during the vigorous growth stage a thin liquid fertilizer should also be applied once a week. It is a crop that likes nitrate nitrogen, so do not apply ammonium nitrogen fertilizers such as ammonium sulfate and ammonium bicarbonate. Zinnias like sufficient sunlight and avoid shaded environments. Keeping the environment ventilated can prevent leggy growth and reduce the occurrence of powdery mildew. Zinnias like warmth and are not cold-tolerant; their optimum growing temperature is 20-30°C. After frost in autumn, the plants gradually die.

The above are the key technical points for planting zinnias introduced by Duorou Huapu for everyone. We hope they can be helpful to everyone. Welcome to continue following Duorou Huapu to learn more small tips on the care and planting of Asteraceae plants.