How to grow gardenias best? A full analysis of care and management key points

Gardenias stay evergreen year-round and bloom around the Dragon Boat Festival each year, with pure white flowers, dense blossoms and overflowing fragrance. They are excellent plants for city landscaping, highway greening and courtyard bonsai appreciation, so gardenias have always been favored by people. But after many people buy one, they do not know how to grow it. Now follow the editor to take a look at how to grow gardenias!

The growing environment for gardenias

Gardenias like a warm, humid environment with plenty of light and good ventilation, but they dislike strong direct sun. They are suitable for living in slightly shaded places, tolerate partial shade, fear waterlogging, and are relatively cold-tolerant. In Northeast China, North China and Northwest China, they can only be grown as greenhouse potted flowers.

Propagation methods for gardenias

Gardenias can be propagated by many methods, both sexual reproduction and asexual reproduction. Generally, cutting and layering are mostly used for propagation. Division and sowing can also be used, but they are rarely adopted. Generally, potted plants in the north are not easy to set seed.

1. Sexual reproduction

Generally, choose plump, dark red mature fruits, dry them in the sun or in the shade with the shell on to use as seed. Before sowing, cut open the seed fruit skin with scissors, dig out the seeds, rub them apart in hot water, remove floating seeds or impurities, then scoop out the sunken, plump seeds, spread them on a bamboo mat, and place them in a ventilated place to dry off excess moisture. Generally, choose a sunny hillside or soil area with deep, loose, fertile sandy loam for sowing. Land at field edges and corners can be used for planting, or it can be intercropped or relay intercropped with legumes. Before planting, plow the land 1-1.5 chi deep, remove miscellaneous tree stumps, and make beds with a bed surface width of 4-5 chi (the spacing can be larger if the soil quality is good, otherwise smaller), with a bed height of 6 cun. Apply farmyard manure, green manure or human and livestock manure water as base fertilizer, for example, apply 20-30 dan of human excrement and urine per mu. After the soil dries, shallowly rake the clods and level the bed surface. Open sowing furrows on the bed surface at a row spacing of 6-7 cun, with a furrow depth of about 1 cun, ready for sowing.

Gardenias can be sown in spring or autumn, generally mostly in spring. Spring sowing is done around Yushui, and autumn sowing is done around Qiufen. When sowing, mix the seeds with wood ash and evenly sow them in the sowing furrows, then cover and level the sowing furrows with fine soil or burnt soil, cover with grass and sprinkle water, and often keep the soil moist to help emergence. Use 4-6 jin of seed per mu. After emergence, pay attention to removing the covering grass in time. During the seedling stage, weed frequently, being careful not to damage the seedling roots. After weeding, topdress with diluted human excrement and urine water each time. After one year of seedling cultivation, they can be transplanted. If transport is relatively far, it is advisable to coat the roots with yellow mud slurry, cover with grass to retain moisture, plant one plant per hole, then cover with soil, press firm and sprinkle water. After planting, cultivate and weed and topdress once each in spring and summer every year. Human and livestock manure, barnyard manure, compost, cake fertilizer and so on can all be applied. Before flowering in summer, it is better to apply fertilizer with more phosphorus and potassium. Fertilization is generally done after weeding and loosening the soil.

2. Asexual reproduction

① Cutting method: It can be divided into spring cuttings and autumn cuttings. Spring cuttings are carried out in mid-to-late February; autumn cuttings are carried out from late September to late October. There are slight differences between the north and the south, but the survival rate is mostly highest between summer and autumn. For cuttings, choose healthy 2-3 year old branches, cut 10-12 cm, remove the lower leaves, keep the top two leaves and cut each in half, first dip in vitamin B12 injection, then insert obliquely into the cutting bed, leaving only one node above. Pay attention to shading and maintaining a certain humidity.

Generally, roots can form in 1 month. Under conditions of 80% relative humidity and a temperature of 20-24°C, it takes about 15 days. If soaked in 20×10^-6 to 50×10^-6 indolebutyric acid for 24 hours, the effect is even better. When the rooted seedlings begin to grow, transplant them or pot them individually. They can bloom after 2 years. In the south, water cutting propagation is also used, that is, inserting the cuttings into a round disc woven from reed stems, letting it float on the water surface so that the lower part roots in the water, and then transplanting for cultivation.

② Layering method: Generally carried out around Qingming in April or during the plum rain season. In April, select 1-year-old robust branches 25-30 cm long from 3-year-old mother plants for layering, pull them to the ground, and wound the part of the branch that enters the soil. If the wounded part can be dipped in 200 ppm powdered naphthalene acetic acid and then covered with soil and pressed firm, rooting is even easier. If there is a three-forked branch, then at the fork opening, three seedlings can be obtained at one time. Generally, roots form after 20-30 days. After rooting in June, they can be separated from the mother plant, and by the next spring they can be divided and planted with soil or potted individually. For transplanting seedlings or potting, spring is best, carried out during the plum rain season, and a soil ball is needed. During the growing period, keep the soil moist, and water more during the flowering period and midsummer. Fertilize once a month, and apply phosphorus and potassium fertilizer once more before flowering. In early spring of the following year, prune and shape, and promptly cut off dead branches and leggy branches.

After looking at the growing environment and propagation methods of gardenias, let us now take a look at how gardenias should actually be grown!

Care and management of gardenias

Gardenias should be repotted every year from April to May. The potting soil can be made by mixing alum fertilizer water residue, sandy soil, fine cinder ash and leaf mold. The suitable growing temperature is 20°C-28°C. From late spring to early autumn, when the weather is hot, pay attention to shading, preventing high temperatures, preventing direct sunlight and preventing poor air circulation. Otherwise the leaves turn yellow.

1. Soil: It is advisable to use fertile acidic soil rich in humus for cultivation. This is the key to successful planting for northern households. Generally, one part leaf mold plus decomposed soybean cake fertilizer can be used, while mixing in a certain amount of ferrous sulfate, or after potting, drench thoroughly 3 to 5 times with 0.2% ferrous sulfate or alum fertilizer water.

2. Cultivation: Use cutting seedlings and layered seedlings for planting. Make sure the plant roots are fully spread out, and at the same time use fine soil to fill the gaps in the root system firmly. The density of the filled soil should be about 85%, and note that it should be firm below and loose above, with a depth of about 1 cm above the root system. After planting, water thoroughly in time, generally with water seeping from the bottom of the pot as the standard.

3. Management and care: Gardenias require relatively high air humidity. Northern households can put clear water in the saucer and place a thin board (about 3 cm) on it. The water in the saucer should not cover the thin board. Place the flower pot on the thin board, and be sure to add water frequently. The principle of watering is to water thoroughly after the soil dries out. Rainwater, snow water or fermented rice washing water is best for watering. If it is tap water, let it sit for 2 to 3 days before use. During the growing period, water once every 7 to 10 days with water containing 0.2% ferrous sulfate or apply alum fertilizer water once. In summer, gardenias should be placed in a shaded place with scattered light for care. In spring, summer and early autumn, water frequently and spray the leaves to increase humidity. In winter, place them in a sunny place, stop fertilizing, and do not water too much. You can often rinse the branches and leaves with water close to room temperature to keep the leaf surface clean, especially in heated rooms in the north. Do not place the flower pot directly in front of a radiator or air conditioner to avoid leaf dehydration.

4. Pest and disease control: Gardenias are prone to scale insects, red spiders and sooty mold in summer high temperatures and poor ventilation. Spray 40% dimethoate emulsifiable concentrate at 1000 times to prevent scale insects, and 40% dicofol emulsifiable concentrate at 1000 to 1500 times to control red spiders. At the same time, it can also reduce the occurrence of sooty mold. For safety at home, washing powder solution can be sprayed, which also has a certain effect.

5. Repotting: Generally repot once every 1 to 2 years, best done in spring. In order to effectively prevent the potting soil from becoming alkaline, repot once a year. Before repotting, the pot must be knocked loose. Knocking the pot loose is done when the pot is dry and slightly loose, generally after stopping watering for about 10 days. When repotting, cut off some roots, such as diseased and pest-damaged roots and overly dense roots, then plant again.

6. Shaping and pruning: Generally carried out in spring. Cut off overly long leggy branches, weak branches and other messy branches that affect the plant shape, so as to keep the plant shape beautiful. Gardenias flower at the top, so during the growing season, the tips can be pinched appropriately to promote flower branch growth and increase the number of flowers.

7. Gardenias like acidic soil, while northern soil is mostly neutral or slightly alkaline, resulting in a lack of iron elements available for the plant in the soil. This is one of the main reasons causing gardenia leaves to turn yellow. Therefore, to grow gardenias, choose fertile acidic culture soil. Generally, mix 4 parts leaf mold, 4 parts garden soil and 2 parts sandy soil. Mix 1 g-2 g of sulfur powder into each kilogram of culture soil. It is best to water gardenias with rainwater or fermented rice washing water. During the growing period, apply 0.2% ferrous sulfate water once every 10 days-15 days, or apply alum fertilizer water once every 10 days-15 days (the two can be alternated). This can not only prevent the soil from becoming alkaline, but also supplement iron elements to the soil, thereby preventing the leaves from turning yellow.

8. Gardenias like moisture. In addition to often keeping the potting soil moist at ordinary times, you must also often pay attention to increasing air humidity. This is because the northern climate is different from the south. Northern spring is dry and often has dry winds, summer has high light intensity and hot weather, and winter is cold and dry. Therefore, in spring and summer, spray the leaf surface with clear water every morning and evening and also sprinkle water on the nearby ground to increase air humidity. In winter, water less, but still spray and wash the branches and leaves frequently to keep the leaf surface clean.

9. Gardenias like partial shade and fear strong direct sun. The shading degree should be about 50%. If exposed to strong sun, the leaves easily turn yellow, turn white and even fall off. Therefore, in summer they must be placed under a shade shed or in a place with scattered light for care, allowing them to see sunlight in the morning and evening, so as to prevent the leaves from turning yellow.

10. Gardenias like fertilizer. When potted, in addition to applying organic fertilizer as base fertilizer when repotting, topdressing should also be applied frequently during growth and development, with thin fertilizer being suitable. In addition to frequently applying alum fertilizer water, after budding, apply fast-acting phosphorus fertilizer 2 times-3 times more, such as 0.5% superphosphate.

11. Gardenias are not cold-tolerant, so pay attention to bringing them indoors and outdoors at the appropriate time. Generally bring them indoors in mid-October, and keep the room temperature at 10°C-12°C, not lower than 0°C at minimum. In spring, do not take them outdoors too early. Usually it is better to take them outdoors in late April.

How to grow gardenias? Precautions for gardenia care

The song "Gardenia Blooming" has awakened the youthful memories of many people and also attracted many friends who want to grow gardenias at home. So, how should gardenias be grown? What key points need attention? Let us learn about them together:

Image: Gardenia

1. Soil

Gardenias like to grow in acidic soil containing more humus. It can be mixed and used as 4 parts leaf mold, 4 parts vegetable garden soil, 1 part soybean meal (decomposed) and 1 part river sand, with good water permeability and air permeability, plus 0.5% black alum or sulfur.

2. Temperature

20-25°C is the best temperature for gardenia growth and development, and the suitable flowering temperature is 26-28°C. Plants cultivated for 4-5 years can endure short-term low temperatures of -3°C, and below -5°C they suffer freezing damage, with leaves turning black and then falling off, and young tender branches freezing to death. In winter, indoor care should preferably maintain 6-10°C, and at minimum not lower than 0°C. If the room temperature is above 15°C, open the south-facing doors and windows and ventilate appropriately to lower the temperature. Otherwise it easily causes sprouting, and once low temperatures occur, damage will result, which is extremely unfavorable for growth and flowering the next year.

3. Light

Gardenias like sufficient light, especially in spring and autumn. Give more than 8 hours of sunshine every day, otherwise it is unfavorable for their growth and development and overwintering. In summer, avoid strong sun exposure at noon, otherwise the leaves will turn yellow. Place them in a place with scattered light for care, with a light transmittance of 40-50% as suitable. In winter, place them indoors in a place with direct sunlight facing south.

Image: Gardenia

4. Fertilization

Gardenias are not flowers that especially like fertilizer, but because they grow vigorously and are limited by the limited nutrients in the potting soil, during the growing period they need reasonable fertilizer supplementation. Apply decomposed human excrement and urine or cake fertilizer once about every 10 days. Stop watering 1 day before fertilizing, and water thoroughly once on the day of fertilizing. Stop fertilizing from mid-September. For adult plants, apply sesame paste residue once each in mid-June and mid-August, 0.5-1 liang each time, crushed and fully mixed with the surface soil.

6. Pinching

In order to regulate and control the growth of gardenias, make the plant shape beautiful and promote flowering, when vigorous spring growth is about to stop, pinch off the tips of new branches to promote plump axillary buds at the base of the branches and the formation of flower buds.

Care key points for potted gardenias

Gardenia (detailed introduction) has evergreen leaves all year round and fragrant, elegant flowers. It is an important ornamental plant for balconies and courtyards. There are many varieties of gardenias, and potted care is very simple. Follow the steps below for care!

Gardenia (detailed introduction)

1. Choose suitable potting soil

Gardenias like acidic soil, with a suitable pH of 5 to 6. Prepare suitable soil before planting. If the soil acidity and alkalinity are not suitable, later care will be very troublesome.

For cultivation soil, usually choose leaf mold, peat soil plus half garden soil. Do not use coal cinder, or directly buy special soil for clivia, which is convenient and practical.

2. Reasonable fertilization

Gardenias like fertilizer. When planting, add decomposed cake fertilizer to the soil as base fertilizer.

During the growing season, use cake fertilizer and ferrous sulfate to make fertilizer water, and water with it once a week. Fully nutritious organic liquid fertilizer can also be used.

During the budding stage, topdress 1-2 times and water with potassium dihydrogen phosphate aqueous solution, which can make the flowers larger and the fragrance richer.

When the summer temperature is above 35°C and the autumn temperature is above 15°C, stop fertilizing.

3. Scientific watering

Gardenias like a moist and humid environment. During the growing period from April to September, keep the potting soil moist, and water by the principle of watering when dry and stopping when wet. At night, spray to wet the leaves to maintain humidity. If the plant grows too vigorously, do not water at night; water after the sun comes out in the morning.

In alkaline water areas in the north, when watering, let tap water sit for one day before watering. Every 3-5 days, water with a little citric acid aqueous solution, which can keep the leaves emerald green.

4. Give more sunlight

The growth of gardenias requires sufficient sunlight. If placed in partial shade for a long time, the flower branches will be thin and weak and slender. During care, except for shading needed in July/August and at noon and except for winter dormancy, at other times it is enough to care for them in the sun.

5. Good winter dormancy

Although gardenias are cold-tolerant, potted gardenias will suffer root damage after experiencing severe winter, and recovery in spring is slower. But if placed indoors with heating, the temperature is higher and light is insufficient, plant growth slows down, and flowering the next year is later. The best method is to place the potted plant in a 5°C environment to let it go dormant, or wrap the flower pot with insulation material and place it outdoors in a sunny, wind-sheltered place to overwinter.

6. Proper pruning

When the main trunk of a gardenia grows to 20 cm, pinch off the tip, leaving 3-4 branches to promote branching. After flowering each year, prune lightly and cut off weak branches and diseased branches. But gardenias must not be cut back at the branch tips in spring, otherwise it will be difficult for them to bloom that year.

7. Repot and change soil at the right time

Gardenias have strong vitality. Seedlings grow from a few centimeters to several tens of centimeters, so they should be repotted according to the size of the plant. When the length of the plant's branches and trunk is 2-3 times the diameter of the flower pot, repotting is needed. When repotting, trim old roots in time, change half the soil, water thoroughly, and place in partial shade for a week. After new buds grow, move them into the sun.