What are the remedies for yellowing leaf veins in gardenia
Many flower lovers have a love-hate relationship with gardenia. Why is that? Because although gardenia is beautiful, it is difficult to grow. During the process of growing it, yellowing leaves are a common problem. Let me teach you how to solve this problem.
Many flower lovers have a love-hate relationship with gardenia: they love its captivating fragrance and its elegant, pure beauty, but they hate how difficult it is to grow. Gardenia has a light, refreshing scent that gives a feeling of elegance, freshness, and purity. However, when its leaves turn yellow, it is very frustrating. So what causes gardenia leaves to turn yellow? What methods can we use to save them?
1. Watering causes:
1. Too little watering: Many flower lovers are office workers and do not have much time to care for their plants. For plants like cacti, it is fine; not watering for a long time will not cause much of an effect. But gardenia is different. If gardenia is not watered for a long time, the lack of water will cause its leaves to turn yellow.
Solution: When watering, pay attention and be sure to water thoroughly.
2. Too much watering: This situation is relatively common. Too much watering will make the leaves turn yellow.
Solution: Change the soil for the gardenia, or place the flowerpot in a ventilated place to dry naturally, and reduce the amount of watering.
2. Fertilization causes:
1. Too much fertilizer: Because too much or too concentrated fertilizer is applied, the leaves and vines turn yellow.
Solution: Wash the roots of the gardenia with water and repot it with fresh soil.
2. Too little fertilizer: Because too little fertilizer is applied, it can also cause the problem of yellowing gardenia leaves.
Solution: Pay attention to fertilizing regularly. If you find the soil has caked, you can change the soil for the gardenia.
3. Points to note:
Gardenia likes warmth and moisture, and direct sunlight should be avoided in summer; however, if it does not see sunlight for a long time, it will also fail to carry out photosynthesis, causing the leaves to turn yellow and fall off.
Now that you understand these causes, do you know how to save your beloved plant? I hope this can help you and let your gardenia grow healthily and remain elegant and charming forever.
What to do when small-leaf gardenia leaves turn yellow, and how to save them
Flower lovers often encounter the situation of small-leaf gardenia leaves turning yellow. The causes of yellowing leaves are varied, and only by finding the real cause can the right remedy be applied.
1. Cause of yellowing leaves in small-leaf gardenia: iron deficiency in small-leaf gardeniaSymptoms
When the plant is deficient in iron, it first shows on the young leaves. The overall performance of the plant is as shown below: the leaves gradually lose green from the edges toward the veins. In severe cases, the veins lose green, and eventually the leaves become scorched and withered due to water deficiency.
How to handle it:
Water once every 10 days with ferrous sulfate water or black alum water diluted 500 times
2. Small-leaf gardenia potting soil too wetThis situation most often occurs with beginners. Usually, after flower lovers buy a plant and water it excessively, the old leaves turn yellow.
Symptoms
In newly purchased gardenia, the edges of old leaves turn yellow while the veins remain green. Many cases are caused by sudden environmental changes.
How to handle it
Remove the yellow leaves and wait for new leaves to grow.
3. Small-leaf gardenia exposed to strong summer sunWhen exposed to strong summer sun, small-leaf gardenia leaves will not only turn yellow, but also develop sunburn spots.
In fact, soil, water, light, ventilation, and humidity complement one another and need to be considered comprehensively and managed together.
4. Small-leaf gardenia magnesium deficiencySymptoms
Unlike iron deficiency, the symptoms of magnesium deficiency first appear on the lower old leaves. The lower leaves lose green and turn yellow, but the upper leaves remain green. In severe cases, the whole plant loses green.
How to handle it
Supplement whatever is lacking. For magnesium deficiency, it is recommended to spray the leaves with a 1% to 2% magnesium sulfate solution, applying it according to the plant's condition, about once every 10 days. After the situation improves, reduce the dosage and lengthen the application interval. This is because absorbing too much magnesium will hinder the development of xylem in the roots and stems.
5. Small-leaf gardenia fertilizer-induced yellowingThat is, excessive fertilizer application raises the soil pH and thus shows yellow-leaf symptoms.
Symptoms
The veins lose green and turn yellow, while the surrounding leaf blades remain green; or after fertilizing, the leaves as a whole lose green and even become dry and yellow.
How to handle it
Flush the roots heavily with water and remove the plant from the pot to wash the roots, washing away as much of the excess fertilizer elements in the soil as possible.
Rubber plant Ficus elastica Roxb. ex Hornem Rubber plant profile: how to grow rubber plant / how to propagate rubber plant
Rubber plant fact fileRubber plant Ficus elastica Roxb. ex Hornem
Rubber plant cultivation methods and precautions Rubber plant introduction
The rubber plant is an evergreen tree in the Moraceae family. It is native to India and Malaysia, so it is also called Indian rubber tree and Indian banyan. It is cultivated in many places across China. It likes a hot, humid, sunny environment, and can also tolerate shade but not cold. The rubber plant has an obvious trunk with few branches and aerial roots. The leaves are alternate, long-elliptic, thickly leathery, bright green, with many parallel lateral veins, young leaves red, and stout petioles. The rubber plant has high ornamental value and is a famous potted foliage plant. It is extremely suitable for indoor beautification arrangements. Small and medium-sized plants are often used to beautify living rooms and studies; medium and large plants are suitable for placement on both sides of the entrance halls of large buildings and in the center of lobbies, appearing majestic and spectacular and able to display a tropical flavor.
Evergreen woody foliage plant. Rubber plant leaves are relatively large, thickly leathery, glossy, round to long-elliptic; the upper surface is dark green and the underside is light green. It is initially wrapped outside the apical bud, and after the new leaves expand, the stipules fall off and leave stipule scars on the branches. Its variegated varieties have yellow-white patches on green leaves, making them even more beautiful and pleasing to the eye, but its leaves are toxic. The rubber plant is an evergreen tree in the Moraceae family and can reach more than 25 m in height. On the leaves, the young leaves are rolled inward, thickly leathery, glossy, elliptic to long-elliptic, with the upper surface dark green or red-green and the underside light green.
There are very many species in the same genus, about 1000 to 2000 species, widely distributed in tropical and subtropical regions. There are about 120 species in China.
It likes a hot, humid, sunny environment, and can also tolerate shade but not cold.
[Propagation]: Cuttings are commonly used. It is best done in spring and summer. Select a one-year-old branch from the upper part of the plant, 20 cm long. After cutting, it roots in 30 days and can be potted in 50 days.
[Cultivation]: For potted seedlings, the pot must be changed every spring. Adult plants can be repotted once every 2-3 years to add fertile soil. Pay attention to watering in midsummer. During dry periods, water can be sprayed on the leaves to keep them moist. Fertilize once every half month. When the plant grows to 1 m tall, it needs to be topped to promote branching and maintain a beautiful tree shape. In autumn and winter, watering should be reduced.
[Pests and diseases]: Anthracnose, leaf spot, and gray mold are common, and can be sprayed with a 500-fold dilution of 65% zineb. Pests include scale insects and thrips, which can be killed by spraying with a 1000-fold dilution of 40% omethoate emulsifiable concentrate.
[Morphological characteristics]: It is an evergreen large tree. The bark is smooth and gray-brown, and the branchlets are green with few branches. The leaves are elliptic, 10-30 cm long, thickly leathery, with a blunt caudate apex, rounded base, entire margin, dark green upper surface with gray-green or yellow-white markings and brown spots, and light green underside. The stipules are reddish brown, wrap outside the apical bud, and fall off when the new leaves unfold. The whole plant has milky sap. Variegated rubber plant leaves are broad and glossy, with beautiful colored patches, and the tree shape is lush and dignified.
[Growth habits]: It likes a warm, humid environment. The suitable growth temperature is 20-25°C, and the safe overwintering temperature is 5°C. It likes bright light and avoids direct sunlight. It tolerates dry air. It avoids clayey soil and does not tolerate poor, thin soil or drought. It likes loose, fertile, well-drained, slightly acidic soil.
[Landscape uses]: Small plants can be placed on windowsills or tables, while medium and large plants are suitable for halls, offices, and meeting rooms.
Morphological characteristics of the rubber plant
Evergreen tree. Plant height 2-3 m. The stem is hairless and has milky sap. The leaves are thick, leathery, with long petioles, and the leaves are oblong or elliptic. Rubber plant leaves are thick and beautiful, broad, attractive, and glossy. The red growing tip resembles a lying cloud, and when the stipules split open they look just like a red tassel hanging down, quite charming. It is a potted foliage plant. Suitable for indoor beautification arrangements.
Distribution area of the rubber plant
The rubber plant is native to India, Malaysia, and other places, and is now cultivated in many places across China. It likes a hot, humid, sunny environment. The suitable growth temperature is 20-25°C, and it avoids direct sunlight. It can also tolerate shade but not cold, and the safe overwintering temperature is 5°C. It tolerates dry air. It avoids clayey soil and does not tolerate poor, thin soil or drought. It likes loose, fertile, well-drained, slightly acidic soil.
Rubber plant cultivation techniques and key cultivation points
(1) Temperature: It likes warmth. The most suitable growth temperature is 20-25°C. It tolerates high temperatures and can still grow well above 30°C. It is not cold-tolerant. The safe overwintering temperature is 5°C. Variegated varieties have slightly weaker cold tolerance, and the overwintering temperature is best maintained above 8°C. Low temperatures will cause a large number of leaves to fall.
(2) Light: It likes bright indirect light and has a certain ability to tolerate shade. It is not tolerant of strong sunlight exposure. When light is too strong, it will scorch the leaves, causing yellowing and scorched leaves. It should also not be too shady, otherwise it will cause a large number of leaves to fall and make the beautiful patches of variegated varieties fade. From May to September, shading should be provided, or the plant should be placed in a place with sufficient indirect light. At other times, it should be given sufficient sunlight.
(3) Watering: It likes a moist soil environment. During the growing period, water should be supplied fully to keep the potting soil moist. In winter, watering needs to be controlled. When the temperature is low and the potting soil is too wet, it easily causes root rot.
(4) Environmental humidity: It likes a humid environment. During the growing season, when the weather is clear and the air is dry, water should often be sprayed on the branches, leaves, and surrounding environment to increase relative air humidity.
(5) Fertilization: Because it grows rapidly, nutrients should be supplied in time to keep the plant growing vigorously. A nitrogen-based fertilizer should be applied 2-3 times per month. Variegated varieties grow relatively slowly, so the number of fertilizer applications can be reduced, while potassium fertilizer should be increased to make the patches on the leaves brighter and more colorful. If too much nitrogen fertilizer is applied or only nitrogen fertilizer is used, the patch colors will fade and even disappear. In September, nitrogen fertilizer should be stopped, and only phosphorus and potassium fertilizers should be applied to improve the plant's cold resistance. In winter, the plant goes dormant, so fertilization should be stopped.
(6) Pruning: In spring, pruning should be carried out together with moving the plant out of the shed, removing forked branches, inward-growing branches, dead branches, and thin weak branches inside the crown, and cutting back protruding branches that stick out of the crown, so as to keep good ventilation and light penetration inside the plant and maintain a rounded tree shape. If the crown is too large, the outer branches can be shortened as a whole. During the growing period, excessively dense branches should be thinned at any time and long branches should be cut back.
(7) Repotting: Usually the pot needs to be changed once every 2 years. It likes fertile, loose, well-drained sandy loam. The growing medium can be prepared from garden soil, leaf mold, and coarse sand, while farmyard manure is mixed in as a base fertilizer.
(8) Pest and disease control: There are diseases and pests such as leaf spot and red spider mite, Ficus thrips, and scale insects.
Choice of growing soil
For pot cultivation, use peat soil and leaf mold plus 1/4 river sand and a small amount of base fertilizer to make a growing medium, or fine sandy soil can also be used. The rubber plant grows quickly and likes fertilizer; apply fertilizer once a week. Usually, before the new shoots grow in spring, change the pot or change the soil. When the seedling is 80 cm to 100 cm tall, pinch the growing tip as needed to promote lateral bud sprouting. Generally keep 3 main branches and remove the other excess ones. If cultivated well, in about 3 years it can grow into a large plant 2 m tall. The rubber plant likes strong sunlight. From spring to autumn, during the entire growing season, it should be cultivated in sunlight; in winter it should also be placed in the brightest place indoors. If placed indoors for viewing, generally replace it about once every 2 weeks, and it should not be kept there too long. The rubber plant grows very fast in a high-humidity, moist environment, producing one leaf every 5-7 days. During this period, sufficient fertilizer and water must be ensured. In autumn, gradually reduce fertilization and watering to promote solid branch growth. Because the rubber plant has strong resistance to arid environments, cultivation in North China is also relatively easy. It should be placed in a room above 10°C for overwintering. Long-term low temperature and wet potting soil easily cause root rot. From the end of April to the beginning of October each year, move it outdoors for cultivation.
Potted maintenance
1. Soil preparation
When potting the rubber plant, it is suitable to use 1 part leaf mold, 1 part garden soil, and 1 part river sand, and add a small amount of base fertilizer to make the growing medium.
2. Watering and fertilizing
It grows very fast in a hot, humid environment, producing one leaf every 5-10 days. During this period, sufficient fertilizer and water must be ensured. Generally, apply liquid fertilizer or compound fertilizer 1-2 times a month, while maintaining relatively high soil moisture. After the beginning of autumn, gradually reduce the frequency of fertilization and watering to promote solid plant growth and help it overwinter.
3. Sunlight
The rubber plant likes strong sunlight. From spring to autumn, it should be cultivated in sunlight throughout the growing season, and in winter it should also be placed in a place with relatively strong light; but it can also tolerate shade and grows fairly well when cultivated indoors under low light.
4. Pinching
In addition, to make the plant grow symmetrically and ensure a good plant shape, pinch the growing tip when the seedling reaches 50-80 cm in height to promote lateral bud sprouting; after the lateral branches grow, select 3-5 branches, and then shorten the lateral branches once each year. After 2-3 years, a relatively large plant with a complete, rounded, and full shape can be obtained.
5. Pruning tips: The central stem usually grows straight and without branches. Regularly prune the growing tip so that lateral branches form as it grows. By simply cutting off the top, it becomes too tall and lanky, and you can control its height. Use sharp pruning shears to avoid tearing the stem.
6. Change water regularly: to keep the rubber plant healthy. When rubber plant leaves turn yellow and fall off, it is a sign of excessive water. [7]
Points to note
[Watering]: It is enough to keep the soil often on the dry side or slightly moist. Summer is the stage when the rubber plant needs the most water, so it can be watered more. Winter is the period when the rubber plant needs the least water, so less water should be supplied. Fertilization: In the vigorous growth season, diammonium phosphate, potassium dihydrogen phosphate, and the like should be applied as topdressing.
[Light]: The rubber plant likes strong direct sunlight and can also tolerate shaded environments. However, during cultivation, it should receive no less than 4 hours of direct sunlight each day. If conditions permit, it is best to ensure the plant can receive full sun.
[Ventilation]: Maintaining appropriate ventilation in the environment is enough.
[Temperature]: The rubber plant likes high-temperature environments, so it grows fastest in summer and autumn. The environmental temperature should be kept between 20-30°C. When the environmental temperature is below 10°C, the rubber plant is basically in a state of stagnant growth. The overwintering temperature should not be lower than 5°C.
Propagation methods of the rubber plant
The rubber plant is commonly propagated by cuttings and air layering. Cutting propagation is relatively simple, very easy to root, and grows quickly.
Cuttings
Cuttings are the main method, but air layering or leaf-bud cuttings can also be used. Propagation is mostly carried out in spring. Before cutting, select good branches as cuttings. Branches 1-2 years old are best, with 3 nodes as one cutting. The cutting medium is made by mixing peat, perlite, river sand, and the like. Remove the lower leaves of the cutting and insert it into the medium. After cutting, keep the temperature at about 25°C, and it will root in about 1-1.5 months. During the cutting process, pay attention to moisture retention, often spray water on the cuttings, and place them in a shaded environment for cultivation. After rooting, pot them and enter the normal management stage.
The medium can be prepared by mixing peat soil, leaf mold, river sand, and the like. Slightly acidic is best. Rubber plant leaves are thick, and its water requirements are not very high. In high summer temperatures and dry autumn environments, pay attention to watering and just keep the medium moist. After winter begins, the temperature drops, so watering should be controlled, and the medium can be slightly drier. The rubber plant does not have high fertilizer requirements. In the peak growth season, compound fertilizer can be used once every half month, and no fertilizer is applied in winter. The optimal growth temperature is 20-30°C.
It is generally carried out in late spring and early summer together with pruning. Select a one-year-old woody middle branch as a cutting, keeping three buds as the standard, cut off the lower leaf, fold the upper two leaves together and tie them with plastic, or cut off half of the upper leaves to reduce water evaporation; in order to prevent too much milky sap from flowing out of the cut and affecting survival, promptly smear the wound with plant ash; insert the prepared cutting into a cutting bed with river sand or vermiculite as the medium; after cutting, keep the cutting bed relatively humid and often sprinkle water on the ground (but it must not accumulate water) to increase air humidity. At 18-25°C and under semi-shade conditions, it will root in about 2-3 weeks.
Air layering
Air layering is also relatively convenient to use at home, and the success rate is high. When air layering, select a two-year-old branch, first girdle it with a ring 1-1.5 cm wide; then wrap the wound with moist moss or peat soil, finally wrap it tightly with plastic film, and tie both the upper and lower ends; after 1-2 months, the rooted branch can be cut off and potted.
In addition to daily fertilization, when maintaining rubber plants, there are also two cultivation techniques:
(1) Cutting method. This method is simple to operate, very easy to root, and grows quickly. The cutting time is in late spring and early summer, and it can be carried out together with pruning. Cuttings mostly use one-year-old semi-lignified middle branches. After the cuttings are cut, in order to prevent too much milky sap from flowing out of the cut and affecting survival, promptly seal the wound with clay or plant ash. The length of the cutting is based on keeping 3 buds. Cut off the lower leaf, fold the upper two leaves together, and tie them with thin plastic string to reduce leaf evaporation. Then insert them into a cutting bed with plain sandy soil or vermiculite as the medium. After cutting, keep the cutting bed relatively humid, but do not let water accumulate. The suitable temperature is 18-25°C. Often sprinkle water on the ground to increase air humidity, and do a good job of shading and ventilation. It will root in about 2-3 weeks. After potting, place it in a slightly shaded place, and gradually increase light after the new buds sprout.
(2) Air layering method. For home gardeners, propagation by air layering is relatively convenient, and the success rate is also relatively high. The method is: select a two-year-old branch of appropriate size, good development, and full tissue, make a light ring-shaped girdle about 1 cm wide at the site where soil is to be wrapped, and apply 30-50 ppm naphthalene acetic acid solution, then use wet soil or a moss mixture or water-absorbed vermiculite to wrap the girdled site, tie it on the outside with plastic film, tie the lower end tightly, and leave an opening at the upper end to facilitate ventilation and watering. Pay attention to maintenance. If layered in June, it will root in July-August. After rooting, it can be cut off and potted.
Landscape uses of the rubber plant
Rubber plant leaves are thick and beautiful, broad, attractive, and glossy. The red apical bud resembles a lying cloud, and when the stipules split open they look just like a red tassel hanging down, quite charming. It has high ornamental value and is a famous potted foliage plant. Although the rubber plant likes sunlight, it is also shade-tolerant and has strong adaptability to light, so it is extremely suitable for indoor beautification arrangements. Small and medium-sized plants are often used to beautify living rooms and studies; medium and large plants are suitable for placement on both sides of the entrance halls of large buildings and in the center of lobbies, appearing majestic and spectacular and able to display a tropical flavor.
Rubber plant leaves are large and glossy, evergreen in all seasons, and it is a large shade-tolerant foliage plant. Potted plants are good materials for decorating hotel halls and home rooms. In the south, they are often placed in front of buildings, in the center of flower beds, and on both sides of roads. Its common varieties in the same genus include variegated rubber plant and fiddle-leaf rubber plant. The rubber plant is a green "vacuum cleaner."
Placing some plants in a closed room reduces dust significantly faster than when there are no plants. Dust in indoor air mainly comes from smoking, heating, cooking, office equipment, and the wear and heating of building materials. Dust is divided into two types. One is settled dust, which generally falls naturally to the ground because its particles are relatively large; the other is called floating dust or inhalable particulate matter, whose particles are smaller and always in suspension. Cigarette smoke belongs to this type, and the green plants placed indoors are powerful "weapons" against these tiny particles. Floating dust carries an electric charge, and when it approaches uncharged plants, it is adsorbed onto the plant epidermis.
Therefore, in places where cigarette smoke is relatively concentrated, in addition to placing more green plants, you should also often rinse or wipe the leaf surfaces with a spray bottle, which will make the dust-absorbing effect better. The rubber plant has a unique function of purifying dust and can also purify formaldehyde among volatile organic compounds. The rubber plant can also absorb carbon monoxide, carbon dioxide, and hydrogen fluoride in the air, purifying the air. The rubber plant likes places with sufficient sunlight, which can ensure vigorous photosynthesis and transpiration. For offices with a lot of dust, it is most suitable to place it by the window. The rubber plant is not cold-tolerant, so do not place it in a low-temperature place in winter. Change the pot once every 2-3 years.
Disease control of the rubber plant: anthracnose
The rubber plant is prone to anthracnose, whose pathogen is Gloeosporium elasticae. This disease mainly occurs in the high-temperature summer season, and the main affected part is the leaves. Its symptoms are round or elliptical gray spots appearing on both sides of the veins, and in severe cases the lesions merge into one patch and spread to the whole leaf.
Control methods:
1. Together with pruning, remove diseased branches, diseased leaves, and dead tips to reduce the pathogen.
2. Usually pay attention to light penetration and ventilation, do not place them too densely, and select disease-free plants from which to take cutting branches to propagate seedlings.
3. After the new shoots grow in early spring, spray 1% Bordeaux mixture. From June to September, spray 1% Bordeaux mixture or 0.3 degrees Baume lime-sulfur mixture or 0.5% potassium permanganate once every half month. In addition, before or in the early stage of the disease, spray 50% thiophanate wettable powder, Tuzet, chlorothalonil, carbendazim, and other wettable powders at 500 to 800-fold dilutions.
Gray leaf spot
It is more severe in September-October. Small gray spots first appear and expand into irregular shapes, gray-white inside with dark brown edges. Later the diseased leaves dry and crack, and black granular matter appears. The pathogen invades through wounds.
Control methods:
In the early stage of the disease, spray 50% carbendazim at 1000-fold or 70% thiophanate-methyl at 1200-fold.
Root-knot nematode disease
After the rubber plant is infected with root-knot nematode disease, growth stagnates, the plant becomes stunted and upright, and leaf edges turn yellow or scorched. When the roots are dug open, many nodular growths of varying sizes can be seen on the lateral roots and fibrous roots, namely galls. When the galls are cut open, many yellow-white oval female nematodes can be seen inside. The roots of the affected plant rot, the aboveground plant grows slowly, and in severe cases growth stops and even the plant dies.
Pathogen: Meloidogyne incognita (Kofoid et White), called the southern root-knot nematode, belonging to nematodes. Under the microscope, the female perineal pattern has 1 obviously high dorsal arch, and the dorsal arch is composed of smooth to wavy striae. Some striae branch on the sides, but there is no obvious lateral line. There are often some fine striae curving toward the vulva, and the pattern as a whole is long-oval.
Transmission routes and disease conditions: It overwinters as adults or eggs in diseased tissues or as larvae in the soil. Diseased soil and diseased manure are the main sources of the disease. The following year, overwintering larvae and overwintering eggs hatch into larvae, which invade through the roots, causing initial infection in the field, then cycling repeatedly and continuously causing reinfection. The southern root-knot nematode occurs relatively commonly across the country, mostly in sandy soil or sandy loam. The suitable development temperature for this nematode is 25-30°C. Larvae lose their ability to live when exposed to a low temperature of 10°C, and die after 5 minutes at 48-60°C. They survive in the soil for 1 year, and all die after 2 years. This nematode is most suitable for surviving in warm southern regions. In Baotou in the north, the temperature is not suitable for its growth and development, but many garden plants in the north are transported from the south, and when introduced they are all in the original pot and original soil, so the southern root-knot nematode settles down in Baotou greenhouses or rooms and reproduces and causes damage. The southern root-knot nematode is a dominant species and can infect chrysanthemum, begonia, cyclamen, Excoecaria cochinchinensis, gardenia, peony, tree peony, coleus, snapdragon, carnation, jasmine, rose, small-leaf boxwood, and many other flowers and trees.
Control methods: (1) When propagating rubber plants in the open field, plow the soil deeply to a depth of 24 cm, turn the galls in the surface soil into the deeper layers to reduce the source of nematodes, and at the same time apply more fully decomposed organic fertilizer. (2) Promptly remove diseased and residual roots and bury them deeply or burn them. (3) Chemical control. Apply 10% Miral granules in holes at 5 kg per 667 sq m, or 5% Miral granules at 10 kg per 667 sq m, 3% isofenphos-methyl granules at 10-15 kg per 667 sq m, 3% Miral granules at 1-1.5 kg per 667 sq m at the seedling stage and 1.5-2 kg at the adult plant stage, applied in furrows. It can also be sprayed or irrigated with 250 ml of 40% isofenphos-methyl, i.e. a 1000-fold dilution, with a control effect of more than 85%. (4) For potted plants, apply 15% aldicarb granules per pot, applying 2 g of pesticide per 2 kg of soil.
Yellow leaf phenomenon
1. It is caused by the soil becoming compacted because the plant has not been repotted for a long time. In the early growth stage, the rubber plant needs to be repotted once a year, and the pot diameter should be larger each year. After 6 to 8 years of growth, it can be repotted once every three years. If it is not repotted for a long time, the potting soil will become severely compacted, and the soil aeration will be poor, causing the fibrous roots of the rubber plant to suffocate and die, making it unable to absorb water and nutrients, which causes the leaves to turn yellow and fall off.
The remedy is: when the temperature reaches above 15°C, repot it, cut off the dead root system, and shake off most of the old soil. Remove the yellowed leaves, shorten the stems appropriately, replace the original compacted potting soil with fresh fertile culture soil, and keep the soil moist regularly. This can encourage it to send out new roots, recover to a healthy state, and grow into a plant with many branches. In subsequent care, keep the potting soil well aerated. While keeping the potting soil moderately moist, loosen the potting soil once every 15 to 20 days to avoid repeated watering causing the potting soil to become compacted and leading to root rot or root shrinkage.
2. It is caused by the plant not being fertilized for a long time. The rubber plant likes heavy fertilization and abundant water, and not fertilizing for a long time will cause malnutrition, leading to yellowing leaves. The remedy is: add an appropriate amount of base fertilizer when repotting, remove the yellow leaves, and thereafter apply liquid fertilizer once every half month, mainly phosphorus and potassium fertilizer.
3. It is caused by the winter temperature being too low. The minimum suitable temperature for the rubber plant is above 6 to 8°C. If the indoor temperature in winter is below 5°C, leaves will turn yellow and fall off. The remedy is: raise the indoor winter temperature and be sure to keep it above 6 to 8°C.
4. It is caused by excessive watering or fertilizing. Although the rubber plant is a plant that likes water and fertilizer, if it is watered and fertilized too much, especially from August to September when the weather is still rather muggy, excessive watering will cause water to accumulate in the pot; or if it is watered too much during overwintering while the plant is in the dormant period and transpiration is reduced, the water in the pot cannot be discharged in time; or if raw fertilizer, heavy fertilizer, or concentrated fertilizer is applied by mistake, root rot will occur due to water damage or fertilizer damage, causing the leaves to turn yellow. If the root rot is caused by fertilizer damage, the roots will be accompanied by an unpleasant odor. The remedy is: first cut off the rotted root system until the cut surface is fresh and white latex exudes. Let it air dry briefly until the latex at the wound dries, or apply sulfur powder to the wound for disinfection, or smear clean plant ash or charcoal crumbs on the wound. At the same time, cut off part of the branches to reduce transpiration consumption of water, then repot it. When replanting, it is advisable to use clean, slightly damp fine sand to first surround the root wound, and use fresh loose sandy loam on the outside for planting. Strengthen shading and misting management, and do not water again until the potting soil is dry. As long as the root system of the plant is not too severely damaged, new fine tender fibrous roots will grow from the root wound after one month. In subsequent care, just keep the potting soil slightly moist regularly, do not water excessively, and spray water on the leaves more in the morning and evening.
5. It is caused by indoor air being too dry, so the moisture in the potting soil is insufficient to supply the transpiration needs of all the leaves, causing some leaves, especially the lower old leaves, to turn yellow and even fall off. The remedy is: check the moisture level of the potting soil from time to time, replenish water in time, and spray water on the leaves every morning and evening. If this is still insufficient, spray water on the leaves again around noon. Note: the water temperature for watering and spraying should be basically the same as the soil temperature and room temperature. If the water temperature for watering and spraying differs greatly from the soil temperature and air temperature, it is easy to cause adverse physiological reactions.
6. It is caused by poor indoor ventilation. If the room is not ventilated for a long time, some harmful gases will accumulate, such as excessively high carbon dioxide concentration, which can also cause yellow leaves. The remedy is: open the windows in time for ventilation, and keeping the room ventilated and the air fresh can improve it. In winter, open the doors and windows at noon when the temperature is relatively high to replace the indoor air.
7. It is caused by long-term shading. The rubber plant is a tropical tree species and likes sufficient sunlight and cannot tolerate shade. If it cannot see sunlight indoors for a long time, yellow leaves will also occur. The remedy is: place the plant in a place with sunlight.
8. It may be infected with gray mold. The remedy is: promptly remove and burn diseased leaves when found. Increase indoor light and raise the room temperature. Or alternately spray with 50% vinclozolin (vinclozolin) wettable powder at 1200 times dilution, or 40% chlorothalonil wettable powder at 600 times dilution, once every 7 to 10 days, spraying continuously 2 to 3 times, which can effectively control the spread of the disease.
Classification of rubber plant varieties: varieties and cultivars
Commonly cultivated varieties and cultivars include: golden-edged rubber plant, whose leaf margins are golden yellow; variegated rubber plant, whose leaves are slightly round and whose leaf margins and leaf surfaces have many irregular yellow-white patches, with weaker growth vigor and slower propagation; white-spotted rubber plant, whose leaves are narrower and have many white patches; golden-star broad-leaf rubber plant, whose leaves are much larger and rounder than ordinary rubber plants, brown-red-green when young, and after the leaves mature the red-brown becomes slightly lighter, with sparse needle-head-sized spots scattered near the edges, which can be distinguished with a little attention. It is an excellent variety of rubber plant.
New cultivars
Ordinary rubber plants are mostly green, and the color is somewhat monotonous and lacks vitality. The new rubber plant cultivar introduced from Italy, Black Prince, adds some new interest to the monotonous and dull color of ordinary rubber plants. The name Black Prince sounds somewhat masculine, but its red leaf sheath is like a shy young girl, bright red as if about to drip, revealing charm within its masculinity.
Expert: The biggest feature of the rubber plant is that the leaf color is especially red, and within the red there is green. In particular, unlike ordinary rubber plant cultivars, its leaf sheath is very red, and the edges of the leaves have two rows of very neat small round dots, which is very distinctive and beautiful. The rubber plant Black Prince has an elegant and substantial leaf form, is robust by nature, and can grow all year round.
The rubber plant Black Prince grows fast and has good adaptability. Usually, simple watering and fertilizing are enough, and no special management is needed. Because the rubber plant Black Prince has only just been introduced, compared with ordinary rubber plants, farmers also have an advantage in price when growing it.
In terms of sales, ordinary cultivars do not sell well. The sales volume of the new cultivar is especially large. Compared with ordinary cultivars, the price difference of the new cultivar is half.
The rubber plant Black Prince can be grown in pots or in the ground. In the north it is more suitable for indoor care, and in the south it is an excellent cultivar for outdoor greening. Black Prince likes warmth, likes color, and tolerates shade. Farmers should pay attention to heat preservation when growing it. Its temperature cannot be lower than zero degrees; below zero degrees it will suffer cold damage. It is generally recommended to use protected cultivation. When watering normally, try to keep it a little wetter and water more. In high temperatures, shade it, because too strong light easily burns its leaves.
Black Prince is a rare excellent product among rubber plants, adding one more choice while beautifying life.
Uses and purposes of the rubber plant
1. The rubber plant is an ornamental plant with tropical characteristics
We who have always lived in the northern temperate zone, do we not also long for life in tropical Southeast Asia? With high temperatures and humidity all year round, the plants are all emerald green with thick, large leaves. Then the rubber plant is a very good choice. It does not require you to set aside a large space for it; with just a small flowerpot it can quietly grow on its own. Evergreen all year round, it has thick leaves that seem to give off the flavor of sunny beaches, allowing you to appreciate tropical style right at home. Therefore, the rubber plant is a green ornamental bonsai that many tropical plant lovers like to grow at home.
2. Refusing secondhand smoke
Many men, because companies and public places outside are designated as no-smoking areas, start smoking at home. Secondhand smoke is very harmful to other family members, especially women, the elderly, and children, seriously affecting their health. But if a pot of rubber plant is kept at home, it is not only ornamental but also has a very good effect on purifying the air and absorbing secondhand smoke and toxic gases. If your home has just been renovated or there is a heavy smoker in the family, you must buy an air purifier for your family: the rubber plant!
3. A plant that grows tenaciously on its own
The rubber plant is a plant with very strong vitality and also strong adaptability to the environment, so generally when you buy a pot of rubber plant, it does not need careful daily care and can still grow very vigorously. It is like a selfless family member who does not need anything in return from you but every day offers you a share of emerald green and a safe air environment. Many flower lovers greatly like this quality of the rubber plant.
Rubber plant pictures