Clivia Cultivation Techniques: Pot Propagation Methods and Pest and Disease Control
The flower language of Clivia is "gentle and courteous," and it also carries meanings such as firmness and unyielding spirit. Many people grow Clivia, and the most common method of growing it at home is in pots, so what should be noted when growing potted Clivia? The following detailed introduction to Clivia will give you a deep understanding of this plant.
1. Biological Characteristics
Clivia is a perennial herbaceous flowering plant that is not cold-tolerant and also dislikes high temperatures and intense heat. It prefers a semi-shaded and humid environment, fearing both cold and heat. The suitable growth temperature is 15 to 25 °C, and during the flowering period it should be kept at 15 to 20 °C. When the temperature drops below 10 °C, the plant grows and develops slowly. In winter, the temperature should not fall below 5 °C. When it drops below 5 °C, growth and development are inhibited; when it drops below 0 °C, mild cases result in frostbitten leaves, and severe cases kill the entire plant. When the temperature exceeds 30 °C, the plant is forced into dormancy, resulting in a short flowering period and pale flower color. Ventilation and cooling should be carried out, otherwise the plant will become leggy, with thin, long, soft leaves. Clivia requires an air humidity of 60% to 80%, under which the leaves are dark green, tender, short, wide and neatly arranged; when humidity is below 60%, young leaves become pale and yellow and even wilt, and in severe cases the entire plant wilts and dies; when humidity exceeds 90%, stems and leaves become leggy; when water content is 20% to 40%, excessive soil moisture easily causes root rot. The loam soil should be loose, fertile, well-drained, humus-rich, slightly acidic sandy soil, and it prefers ventilated, deep, fertile and loose leaf mold. The roots of Clivia are thick and well-developed fleshy fibrous roots. The leaves are dark green, broad, leathery, with the leaf bases forming a pseudobulb; the leaves are arranged in two opposite rows overlapping like swords with entire margins. The flower scape emerges from the leaf cluster, arranged in a semicircular or flat-round umbel, with funnel-shaped flowers. The flowering period lasts all year, mainly in spring and summer. The fruit is a spherical berry, each fruit containing 1 to multiple seeds, and the fruit ripening period is about 10 months.
2. Propagation Methods
In northern regions, Clivia is mostly propagated by division, while seed propagation is common in southern regions where conditions are close to the climate of its place of origin. Remove the mother plant that can be divided from the pot, remove the old soil and dried roots, and use tools or hands to separate the offset shoots from the mother plant at the connection point. Then apply some plant ash to the wound to absorb the flowing sap and prevent rot. Let it dry for a few hours, and once slightly dry, pot it up. Division propagation is the most widely used method and can be carried out in all four seasons, as long as the temperature can remain stable at around 20 °C. Plants propagated by division have the most stable genetic traits.
3. Cultivation Management
3.1 Fertilization
The main fertilizers needed by Clivia are nitrogen fertilizer (decomposed soybean cake, peanut cake, peanuts, sesame, sesame oil residue, castor beans, etc.), phosphorus fertilizer (fermented and decomposed rice bran, bone meal, fish scraps, etc.) and potassium fertilizer (charcoal, rice straw, plant ash, rice husk ash, etc.). Clivia fertilization follows the principle of "light fertilizer applied frequently," mainly using organic fertilizer, appropriately combined with inorganic fertilizer. Fertilizer must not directly touch the roots to avoid burning them. Apply fertilizer amounts according to growth characteristics. In spring and autumn, growth is rapid, so more fertilizer can be applied; in summer and winter, it should be reduced or stopped. At the same time, observe the effect of fertilization. In winter, if spots appear on new leaves and roots turn yellow, it indicates excessive fertilization, while new leaves that are narrow, thin and particularly pale indicate fertilizer deficiency.
3.2 Watering
Clivia prefers moisture and must not lack water throughout the plant's growth period. It has well-developed fleshy roots that store a certain amount of water, so this flower also has some drought tolerance. The amount and frequency of watering should be controlled according to its growth cycle and different seasons. Watering should follow the principle of "water when dry, not when wet; do not water if not dry; water thoroughly when dry, but not to the point of leakage." In summer, under high temperatures and dry air, severe water shortage must be avoided, otherwise the potting soil may become too dry, causing leaves to turn yellow and the flower's roots to be damaged, preventing new leaves from sprouting, which not only affects flowering but may even cause the plant to die. In summer, it is best to spray water on the leaf surface and surrounding soil every morning or evening with clean water to maintain a cool environment. Overwatering can cause root rot and lead to pest and disease problems, so in spring and autumn keep the potting soil moist, and in winter slightly drier. During the flower scape emergence period, water should not be applied to the leaves to avoid scape rot. After flowering, appropriately reduce watering, and be careful not to splash water droplets on the flowers to avoid petal rot and shortened flower lifespan.
3.3 Light
Clivia is a semi-sun-loving, shade-preferring flowering plant that likes diffused light and does not require long light hours. It grows poorly under both strong and weak light conditions. From November each year to February of the following year, no shading is needed; from March to October, shading should be chosen according to light intensity. In summer, place it in a ventilated, shaded area for maintenance. Exposure to scorching sun will cause sunscald and inhibit growth. In spring and autumn, shade from the strong midday sun; in winter, place it in a sunny indoor spot with full light exposure, and the longer the sunlight, the better. During the Spring Festival flowering period, weak light and diffused light can extend the flowering period. Clivia has phototropism. To make Clivia attractive in appearance with neatly arranged leaves, the plant shape should form a straight line when viewed from the side and look like a fan when viewed from the front. The pot should be frequently rotated according to the changing position of the sun. There are two ways to position the pot indoors: one is to place the leaves parallel to the sunny window, and the other is to place the leaves perpendicular to the sunny window, with the latter being more effective than the former. If the leaves become twisted and crooked, light-based shaping should be the main approach, supplemented by manual mechanical shaping.
3.4 Pot Selection and Repotting
During the growth of Clivia, the original pot cannot accommodate further extension of its root system, so the pot size should gradually increase as the plant grows. If the nutrients in the original soil have been completely absorbed, repotting is also needed. Clay pots have good breathability and produce better cultivation results. When repotting, first, the pot diameter should be close to the spread length of the Clivia leaves; second, the planting depth should be appropriate when placing it into the pot. When repotting, remove old, residual and dead roots, being careful to protect the root tips from damage, and manually spread out the root cluster when planting. Repotting should be done in spring and autumn.
3.5 Temperature Control
The suitable growth temperature for Clivia is 15 to 20 °C. Temperatures that are too high or too low have a great impact on Clivia. When the temperature is above 30 °C, leaves become thin and elongated, turning pale and yellow and even wilting. The minimum critical temperature is 0 °C. If the temperature is below zero, frost damage may occur, and leaf tips and margins will turn yellow. Therefore, temperature management is a very important part of Clivia care. In summer and winter, measures should be taken to cool, protect against cold and prevent freezing. In winter, control the room temperature, and the temperature can be increased through heating equipment such as radiators and fan heaters. If the temperature cannot meet the requirements, the pot can be placed on a radiator with a wooden board underneath; otherwise, the growth and development of Clivia will be inhibited, and leaves may even be frostbitten, turning yellow or developing "scape binding." This not only affects the ornamental effect but is also detrimental to the growth and development of Clivia. If "scape binding" occurs, the indoor temperature needs to be increased. In summer, greenhouse temperature can be adjusted by opening windows for ventilation and cooling, and water can also be sprayed on the ground around the potted flowers and on the leaf surfaces to cool and increase humidity. During the "scape emergence" stage, the temperature should be somewhat higher. A flowering period temperature of around 15 °C can prevent "scape binding." A day-night temperature difference of about 8 °C is best, which helps the scape emerge; otherwise, the flower scape will bloom before reaching the proper height, also easily forming "scape binding."
3.6 Leaf Surface Care
Clivia is a flowering plant whose flowers, leaves and fruit are all ornamental. For the large-flowered Clivia, there is a saying that "leaf viewing is better than flower viewing." Therefore, attention should be paid to leaf surface care to improve its ornamental value. Glossy leaf surfaces are one of its main indicators. How to make the leaf surface glossy is related to the following factors: (1) Ensure the root system is well-developed and not rotting; fertilization should be proper and reasonable, and the ratio of phosphorus and potassium fertilizers in the nutrient soil should be scientifically managed. (2) Maintain humidity and pay attention to the moisture level of the leaf surface. Spray water on the leaf surface daily, preferably in a mist form. In the high-humidity season of summer, spray once each morning and evening, with the purpose of reducing water evaporation from inside the leaves. In hot weather, to prevent leaves from becoming leggy and elongated, spraying water reduces water evaporation from inside the leaves, lowers leaf temperature and protects the leaves. (3) There must be sufficient light. In spring and autumn, the recommended light duration should not be less than 8 h. In summer, avoid strong light exposure that destroys chlorophyll, and in winter, increase light as much as possible. When providing light, pay attention to the angle between the plant and sunlight to avoid leaves tilting randomly. If leaves become deformed due to lighting, scape emergence and flowering, or fruit set, they need to be reshaped promptly. (4) Observe the condition of the leaf surface to determine whether the plant has pest or disease problems, adopt corresponding treatment measures, and carry out timely rescue. The optimal ornamental state for Clivia leaves is a leaf width ratio within 4, rounded and blunt leaf tips, and prominently raised leaf veins.
4. Common Problems and Pest and Disease Control
4.1 Root Rot
Common factors causing root rot: (1) Long-term heavy watering under high temperature conditions, causing oxygen deprivation in the fleshy roots of Clivia and leading to root rot; (2) Excessive fertilizer use, causing root burn and root rot; (3) Long-term failure to change potting soil, causing soil compaction and poor aeration, blocking root respiration and leading to root rot; (4) Long-term water shortage causing root withering, followed by excessive watering leading to root rot; (5) Undecomposed leaves and other organic fertilizers in raw soil fermenting in the pot and generating heat that burns the root system, or improper soil selection. When root rot occurs, the main symptoms of Clivia are soft, yellow leaves that appear water-soaked. Corresponding measures should be taken: (1) Remove the Clivia from the pot and remove the rotten roots; (2) Wash the roots with potassium permanganate to disinfect and sterilize, or apply gentian violet, charcoal ash, rice straw ash and other methods to the wounds; (3) Replace with new soil, control the amount of watering, and add fertilizer at the same time.
4.2 Scape Binding
Scape binding manifests as the flower stem developing too short to extend beyond the leaves before opening. It is usually caused by low temperatures, improper watering or insufficient fertilization. The suitable temperature for Clivia scape emergence is around 20 °C. If the temperature during the scape emergence period is below 15 °C, the growth vigor of the flower stem is weakened. When Clivia enters the reproductive growth stage, its fertilizer demand increases. If fertilizer and water are improper during this period, the flower stem will grow poorly under conditions of water and fertilizer deficiency. The method to prevent scape binding is to raise the soil temperature to around 20 °C during the scape emergence period and promptly change the soil and repot. During the scape emergence period, Clivia needs more water than in other periods, so watering should be increased, but the soil should not be overly moist, with a soil water content of 30% being appropriate. When watering, do not pour water between the two rows of leaves. Entering the reproductive growth stage, increase the frequency of fertilization and apply more liquid fertilizer.
4.3 Sunscald
Clivia easily grows under diffused light. In summer, exposure to sunlight will kill leaf cells and cause sunscald. Therefore, outdoors it should be placed in a shaded, humid, ventilated area. Indoors, direct sunlight should be avoided.
4.4 Infertility
The main reason for not flowering is related to light duration. In its place of origin, Clivia receives no more than 13 h of light. However, indoor-cultivated Clivia, due to normal lighting and artificial lighting, receives far more than 13 h. To prevent Clivia from failing to bloom, light duration should be controlled at around 13 h. The phenomenon of flowering without fruiting is mainly related to pollination. The stigma of the Clivia pistil is higher than the anthers of the stamens. If the flowering season is indoors in winter or spring with no insect pollination, artificial pollination is needed to facilitate seed set [Jishan Huayao].
4.5 Diseases
Common Clivia diseases are soft rot, leaf spot and anthracnose. Control methods: (1) Strengthen environmental sanitation and maintenance work, change soil promptly, pay attention to soil disinfection, wash the fleshy roots with clean water when changing soil, and pot them up after drying; (2) Pay attention to ventilation and light transmission, avoiding problems caused by insufficient fermentation of nutrient soil and fertilizer, unsatisfactory soil disinfection and mechanical damage; (3) Before disease onset or in the early stage, spray optional agents: 50% thiophanate-methyl wettable powder at 500 to 700 times dilution, or 75% chlorothalonil wettable powder at 600 to 800 times dilution; (4) Pay attention to fertilizer and water management, improve growth vigor and enhance disease resistance.
4.6 Pests
There are not many common pest species on Clivia, mainly scale insects, snails and earthworms. When only a small number occur, they can be gently removed with a soft brush, rag or bamboo strip, or wiped off with a cloth ball dipped in kerosene, then rinsed with clean water. Before germination, spray once with 3 to 5 times dilution lime sulfur mixture at Baume degrees. During the nymph stage, spray with 80% dichlorvos emulsion at 1,000 times dilution. For earthworms, drench with diluted 50% dichlorvos emulsion.
The above is an introduction to the propagation and pest and disease control cultivation techniques for potted Clivia. Has the above content helped you understand Clivia? Whether grown in pots or in the ground, Clivia certainly cannot do without proper care.
Cultivation Methods and Pest and Disease Control of Clivia nobilis
Clivia nobilis has deep green leaves and an elegant posture. It is a potted flowering plant used for decorating conference venues, embellishing hotels and beautifying home environments. So how do you grow Clivia nobilis? Next, let's learn about the cultivation methods of Clivia nobilis.
I. Cultivation Methods of Clivia nobilis
1. Potting soil: When potting, use a mix of sand and peat, or sand and leaf mold. For adult seedlings, repot once every 2 to 3 years, with pot size determined by the seedling. When repotting, change the soil, and compost it together with cake fertilizer and barnyard manure to promote rapid growth of Clivia.
2. Watering: Clivia prefers a warm and humid environment. Its fleshy roots are well-developed and have some drought tolerance, but it fears waterlogging. When watering, master the principle of alternating dry and wet. Normally, it is best to maintain the relative humidity of the soil at 80% to 90%, not lower than 60%. Wiping the leaf surface with tea water every week can make the leaves fresh and glossy. In short, as long as Clivia avoids wind in spring, avoids sun exposure in summer, prevents rain in autumn and does not become dry in winter, it can maintain vigorous growth with abundant flowers and lush leaves.
3. Temperature: The suitable temperature for Clivia is 15 to 20 °C. Above 25 °C, the plant grows poorly, often becoming leggy and affecting flower bud differentiation; at this time, pay attention to ventilation and cooling. Below 10 °C, growth is slow; below 0 °C, the plant will freeze to death. In summer, pay attention to cooling, which can promote flower bud differentiation. A large day-night temperature difference is beneficial to Clivia growth, generally 6 to 10 °C is suitable.
4. Fertilization: Clivia can be fertilized one month after potting and seedling recovery, applying fertilizer water once every 10 to 15 days, and fertilization should be stopped in summer. In spring, half a month before the two growth peaks arrive, it is suitable to apply dry soybean cake or chicken manure on the pot surface, but not too close to the roots to avoid root damage. After autumn, flower buds begin to form and bloom, and phosphorus fertilizer should be added to make flowers larger and more colorful, and to prevent scape binding. When fertilizing, do not pour onto the leaves or into the leaf sheaths. If fertilizer is insufficient, leaves lose their luster, flowers are few and small, and alternate-year flowering may occur. Regular topdressing is generally carried out in spring and autumn, with less in summer and winter.
5. Light: Clivia has broad leaves and a certain shade tolerance, preferring a semi-shaded environment. Plants grown under 50% light transmittance have verdant green leaves, greatly enhancing the ornamental effect. Light also affects the arrangement direction of Clivia leaves. If light comes from only one side, the leaves originally arranged in a straight line will become disordered, reducing the ornamental effect. Therefore, ensure the plant receives even light and regularly rotate the direction of the pot.
II. Pest and Disease Control of Clivia nobilis
The main diseases include soft rot, anthracnose, leaf spot and southern blight, while the main pests are scale insects.
Leaf blight: Mainly harms leaves, initially appearing as light reddish-brown, elliptical elongated spots with a clear boundary between diseased and healthy tissue, and surrounding tissue turning yellow. Promptly cut off diseased leaves when found; appropriately increase potassium fertilizer, avoid excessive watering and water accumulation on leaves; in the early stage of disease, spray 50% carbendazim wettable powder at 1,000 times dilution.
Root rot (soft rot): During cultivation, tools and substrate must be strictly disinfected; in the early stage of disease, drench the roots with 400-600 μg/L penicillin or streptomycin. In severe cases, cut off all rotten parts, soak the remaining parts in potassium permanganate solution for 1 hour, then rinse with clean water and replant.
Scale insects: Manual control can be used, gently brushing off the insects and sooty mold with bamboo sticks, small wooden sticks, small soft brushes, etc., then rinsing with clean water. During the nymph stage, spray with jiemanling emulsion at 40-100 times dilution.
Cultivation Methods of Clivia nobilisThat concludes the introduction. I hope it is helpful to everyone. Growing Clivia nobilis requires some care so that it can grow more luxuriantly.
What to Do When Clivia Leaves Turn Yellow? Pest and Disease Control Methods for Clivia
What should you do when Clivia leaves turn yellow? Today let's look at the causes and solutions for yellowing Clivia leaves.
Clivia (scientific name: Clivia), also known as sword-leaf lycoris, is an ornamental flowering plant in the genus Clivia of the Amaryllidaceae family. It is native to southern South Africa. In China it is often grown in greenhouses as a potted ornamental. It is propagated by division or seeds. Clivia nobilis (C. nobilis), which has the same uses, is also cultivated in greenhouses in various places.
Perennial herb, with fleshy roots. Basal leaves are leathery, numerous, broadly linear, with leaf bases arranged in two rows closely clasping each other to form a bulb-like structure. It blooms in spring and summer. The flower scape is upright, flat and fleshy, with a terminal umbel bearing numerous flowers, yellowish-red on the outside and yellow on the lower inner side. The berry is purplish-red.
Yellowing of Clivia leaves often occurs in summer, and it greatly affects the ornamental value of Clivia. If your Clivia also shows such symptoms, then quickly look at the following causes and solutions.
The entire leaf turns yellow.
This situation occurs when the sun is too strong and scorches the Clivia. The remedy is to cut off the yellowed leaves and provide shade. After a period of time, the yellowing of Clivia leaves will decrease.
Yellowing starts from the leaf tip.
This situation may be caused by the soil being too raw or too rich, and should be handled according to the actual situation.
Individual leaves turn yellow.
The most likely cause of this situation is insufficient light for the Clivia. The corresponding measure is to supplement with artificial light, or place it in a position with sufficient sunlight.
Yellow leaves in Clivia (including deteriorated leaf tips) are mostly caused by improper watering, fertilizing and soil use, which first cause root rot and then lead to yellow leaves. Therefore, the pot should be turned out for inspection, rotten roots removed, soil replaced and the plant repotted, and the yellow leaves cut off at the same time to reduce the burden on the plant. The main causes of root rot are:
1. Under poor ventilation, a large amount of water will cause root rot, because the water poured into the pot cannot evaporate for a long time, the plant's metabolic function is hindered, and root rot is inevitable.
2. Excessive fertilizer application or application of incompletely fermented fertilizer, when the room temperature rises above 25 °C, will ferment in the pot and generate high temperatures, thereby burning the roots; 3. Using alkaline soil, clay soil or undecomposed horse manure soil to cultivate Clivia, some are not loose, some have poor air permeability, and some will cause high temperatures in the potting soil, which can also cause root rot.
10 Solutions for Yellowing Clivia Leaves
1. Clivia leaves turn yellow, and the small central leaves turn black and rot
Solution: When this symptom appears, first use the above 9 methods to address the root cause. If the small central leaves turn black and rot, further judgment is needed. Pry apart the two leaves to check. If the gap between the leaves is black and exuding decayed sap, it can be determined that the formed Clivia flower scape failed to grow out from between the leaves in time and rotted directly in the middle of the leaves.
There are many causes of flower scape rot: one is that when the flower was in the owner's hands, too much water was sprayed, causing dirty water to flow into the gap and causing bacterial infection and rot; another situation is that careless watering caused dirty water to splash into the gap and cause rot. Consequences: Generally it will not affect the life of the plant, but in high-temperature and high-humidity weather, it can easily cause the crown to rot and the whole plant to decay. Treatment: Use toilet paper or tissue paper to absorb the decayed sap, use appropriate methods to remove the dirt that can be cleaned, keep the environment relatively dry normally, and it is recommended to use the bottom-watering method.
2. All leaves of Clivia turn yellow
Solution: When all leaves turn yellow, it is often a symptom of sunscald. Solution: Immediately provide shade and cut off the yellow leaves.
3. Clivia leaves wither, yellow and droop
Solution: Withered, yellow or drooping leaves are symptoms of water deficiency. Watering should follow the principle of not watering when not dry, and no water accumulation in the pot.
4. Localized yellowing of Clivia leaves
Solution: Localized yellowing is very likely caused by scorching heat, cold wind, hot water or acid-base erosion. Simply eliminate the external cause promptly. Sometimes, nitrogen deficiency may cause the plant to suffer from chlorosis. The reduction of chlorophyll causes leaves to turn yellow. In this case, apply more fermented cake fertilizer water. (Growing methods also differ by season.)
5. Clivia leaves wrinkle and develop yellow spots
Solution: Caused by root burn from excessive fertilization. Immediately change the soil, soak the roots in 0.1% potassium permanganate aqueous solution for 20-30 minutes, rinse with clean water, cut off rotten roots after drying, apply plant ash to the wounds, and replant;
6. The two outer leaves of Clivia turn yellow (grown for 4 years)
Solution: This is normal metabolism of old and new leaf layers. Simply prune off the two outer leaves.
7. Clivia leaves appear grayish-yellow
Solution: The main cause of grayish-yellow Clivia leaves is excessively strong direct sunlight, so the Clivia needs to be shaded.
8. Clivia leaves show chlorosis symptoms
Solution: Due to insufficient light. If the room is very dark, Clivia will become chlorotic. Solution: Supplement light with a fluorescent lamp.
9. Clivia leaves are yellow and weak
Solution: Yellow and weak leaves indicate fertilizer deficiency. Apply light fertilizer frequently; yellow leaves indicate raw, non-breathable soil. Replace with leaf mold or pine needle soil;
10. Yellowing of lower leaves causing root rot
Solution:
Materials: scissors, utility knife, chlorothalonil, rooting solution, nutrient solution, spray bottle.
Procedure:
①: Pull the Clivia out with its roots.
②: Use a utility knife to cut off old leaves and rotten leaves.
③: Use scissors to cut off already rotten roots and old roots.
④: Mix water and chlorothalonil in the spray bottle at a 3:5 ratio.
⑤: Return the Clivia to the pot.
⑥: Water with rooting solution and nutrient solution.
⑦: First water about 2 times a month for 5 months.
⑧: After 5 months, water about 4 times a month for 2 months.
⑨: Resume normal watering frequency.
⑩: Done.
Methods to Prevent Clivia Leaves from Turning Yellow:
The main cause of yellow Clivia leaves is improper management. The causes of yellow Clivia leaves are generally as follows:
1. Overwatering (water-induced leaf yellowing): When the pot accumulates water for too long, leaves easily develop infiltration-type yellowing, occurring at the tips of young leaves, with symptoms developing from top to bottom. This is the common "water yellow," caused by overly frequent watering. Its characteristic is that old leaves show no obvious change while young leaves turn yellow; immediately control watering;
2. Water deficiency (drought-induced leaf yellowing): If it is too dry, or if only half-watering is done each time, old leaves will develop yellow tips. Caused by water deficiency and drought, its characteristic is that old leaves turn yellow first from bottom to top. If water deficiency lasts a little longer, the whole plant's leaves will turn yellow, or even die. Water promptly;
3. Excessive fertilizer (yellowing caused by over-fertilization): Too much or too concentrated fertilizer will cause root burn and yellow leaf tips. Caused by overly frequent fertilization or excessively high concentration; its characteristic is that young leaves are thick, glossy and uneven; control fertilization, carry out intertillage and water;
4. Loss of green due to element deficiency (iron deficiency): If the potting soil lacks iron, leaf tips turn yellow first. If nitrogen is deficient, new leaves appear yellowish-white.
5. Yellowing caused by insufficient nutrients: Caused by insufficient fertilizer, low fertilization concentration, and excessively long fertilization intervals; its characteristic is that young leaves and tender stems turn yellow first. If this phenomenon is seen and fertilizer is not applied in time, it can also cause the whole plant's leaves to turn yellow or even die; for nutrient-deficient flowers, never apply a large amount of concentrated fertilizer at once, to avoid root burn; woody flowering plants in greenhouses, etc., due to large changes in soil fertility conditions, often show yellow leaf phenomena, characterized by obvious young leaves and lighter old leaves, with yellow mesophyll and green veins, forming a typical network pattern; this can be solved by applying ferrous sulfate aqueous solution, with the method being: 7 parts cake fertilizer, 5 parts ferrous sulfate, 200 parts water, mixed into a diluted solution for watering.
6. Sunscald: After strong direct sunlight (in summer), yellow spots appear on the leaves, called sunscald. Under high temperature (above 30 °C) and dry conditions, leaves also easily become yellow and wilt.
7. Pollution: Clivia leaves should be kept clean. If dirty things splash on them, the contaminated areas may turn yellow.
8. Freeze damage: Clivia suffers freeze damage below 0 °C, and the symptom is still yellow leaves. To restore normal growth of Clivia after yellowing, it is necessary to identify the source of the problem and take corresponding measures. The method is: dig out the entire Clivia plant and check the roots. If roots are rotten, remove the rotten parts, replace with new soil and recultivate, placing a layer of fine sand under the roots. The potting soil should be loose leaf mold, with a pH value preferably neutral. Keep the soil neither dry nor wet, with good aeration. Clivia prefers weak light. Except in winter, in summer it should be placed in a semi-shaded, semi-sunny location, avoiding direct sunlight. If "chlorosis" occurs, liquid fertilizer (such as black alum fertilizer water) can be added, with the key being small amounts applied frequently. Be careful not to splash fertilizer liquid or mud onto the leaves or stems. If splashed on the leaves, rinse off promptly with clean water. When applying solid fertilizer, also avoid direct contact with the fleshy roots.
Questions About Treating Yellowing Clivia Leaves
1. Can yellowing Clivia leaves be pruned?
The key is to figure out why there are yellow leaves.
Common causes of yellow leaves:
① Place in a semi-shaded area for maintenance; if the sun is too strong, the leaves will be sunburned and turn yellow.
② Clivia has fleshy roots, so the potting soil only needs to be kept slightly moist. Overwatering damages the roots and causes leaves to turn yellow.
③ Yellow leaves due to fertilizer deficiency. Clivia only needs diluted nitrogen fertilizer once every half month; do not fertilize in midsummer to avoid root damage. Yellowing Clivia leaves can be pruned. Hold the scissors over a flame to disinfect them, then cut off the yellow leaves, but do not tear them.
2. Solutions for yellowing Clivia leaves in spring:
After winter, the Clivia's leaves turned yellow and withered. Will it still survive in spring?
It should be possible. Repot it: remove dead leaves and hollow roots, use special Clivia soil mixed with large pieces of orchid stone, with a soil-to-orchid-stone ratio of 3:2. After repotting, water thoroughly once, place in a diffused-light, ventilated area for 1 month to recover, then gradually expose to light over one week, and resume normal care. Do not expose to scorching sun.
3. Solutions for yellowing Clivia leaves in summer:
Check whether it is usually overwatered. Too much water easily causes root rot, leaf rot and core rot, and water should be poured into the potting soil, not on the leaves, especially not into the central leaves. If the potting soil is often too wet, it will cause water to flow backward, and then, as you described, blackening and rot will gradually appear starting from the leaf tips. Therefore, Clivia potting soil should be on the drier side. In addition, summer temperatures are relatively high. If the growing environment temperature can drop below 25 °C, diluted liquid fertilizer at 1:20 or more can also be applied in summer, once every half month. This can promote the growth of Clivia and shorten or eliminate its dormancy period. There is another situation: light is too strong. Clivia prefers soft light. If exposed to strong direct light, the leaf surface will become rough, the leaf color will turn yellow and dark, losing its emerald green, and it is also prone to "sunscald." =========================================================================
Summary: Growing Clivia is something that requires constant summarizing and discovering problems. Only through careful observation and meticulous care can you grow Clivia with ornamental value. Finally, I wish all friends' Clivia healthy growth.
Common Diseases of Clivia
Diagnosis and Treatment of Diseases
Because of unsuitable cultivation conditions, Clivia is often invaded by pathogens and develops diseases, which in mild cases affect its ornamental value and in severe cases lead to the death of the plant. Therefore, it is very necessary to diagnose the type of Clivia disease at an early stage and take timely control measures.
1. Leaf wilt disease: It occurs at the tip of young leaves, and the symptoms develop from top to bottom. In severe cases, the entire leaf turns yellow and wilts. This disease is caused by root crown rot, also called root rot, which is a relatively serious disease caused by a fungus invading the roots. It mainly damages the root zone (root crown) of the plant and the cortex and phloem of the stem near the ground surface. It is a physiological disease caused by excessive fertilizer or excessive watering. If it is caused by excessive fertilizer, the potting soil should be replaced, with a layer of fine sand placed under the roots; the potting soil should preferably be loose leaf mold, with a neutral pH. If it is caused by excessive water, watering should be controlled, and the yellow leaves should be removed; the plant can still return to normal growth.
2. Leaf spot disease: Small yellow spots appear on the leaves, and the lesions enlarge, reaching about 3?5 mm in diameter, round; when the lesions spread and merge into one patch, the leaves turn yellow and withered. Another type is large lesions on the leaves, irregular in shape, yellow-brown to gray-brown, with slight concentric rings, and later small black dots appear on the underside of the lesions. Both of the above diseases are caused by poor ventilation and parasitism by scale insects, which weaken the growth of the plant. The control methods are: apply 0.5% potassium permanganate solution to the lesions, or spray with 50% carbendazim 1000-fold solution; if the disease is severe, remove the affected leaves and burn them, and dry the wounds with sterile absorbent cotton.
3. Bacterial soft rot: Pathogens invade due to mechanical injury or damage by scale insects, damaging the leaf sheath and leaf center. The rotten part should be cut off, the wound dried with absorbent cotton, and then smeared with 0.02% streptomycin.
Treatment of Root Rot
When Clivia is divided, if the wounds are not disinfected, they are infected by bacteria; or during cultivation, excessive watering, poor soil permeability, overly concentrated fertilizer, or the application of undecomposed raw fertilizer are all common causes of root rot in Clivia. For large mature Clivia plants, if individual roots rot, it will show as dry tips on a certain leaf, blackening of the leaf blade, and scorched shedding. Find the cause, overcome it, and stop the root rot from continuing.
When many roots have rotted, most of the leaves will fall off, leaving only the small central tongue leaves. In severe cases, the plant becomes unstable, and sways and shakes at a light touch of the hand. At this point, when removed from the pot, it can be seen that some of its fleshy roots have rotted entirely, and some are half rotted. The rotted roots have only a shriveled membranous outer skin left, and over time the outer skin also softens and rots. When this situation is found, all the soil should be shaken off, and the roots rinsed clean with clear water. Carefully remove the rotted roots, and cut off the rotten parts with clean scissors. Then soak the roots in a 0.1% concentration potassium permanganate solution for disinfection. After 5 minutes, take out the roots, rinse them with clear water to remove the disinfectant, dip them in a small amount of sulfur powder or plant ash, let the surface dry indoors, and then replant in a pot. When potting, plant shallowly, burying only the stem disc, and the pseudobulb should be exposed above the soil surface, which is beneficial for rooting. After watering once thoroughly, place it in semi-shade for care. Afterward, spray more often or cover with a plastic film, keep the air humidity as high as possible, and water less. Maintain the temperature at around 20°C until the small tongue leaves grow. By then new roots have emerged, and normal water and fertilizer management can be resumed. For young plants, the roots are few and very delicate; if root rot occurs, the roots will quickly rot completely, and the leaves will droop. When these conditions appear, the plant should be removed from the pot in time, the residue on the not-yet-rotted stem disc cleaned off, rinsed, disinfected, and after the surface dries, inserted shallowly into plain sandy soil according to the cutting method. Under environmental conditions of 20-25°C, with shading, maintaining relatively high air humidity and moist cutting soil, let it send out new roots. Once the leaves recover their vitality, repot in time with leaf mold soil.
Common Viruses
Several common diseases of Clivia include southern blight, soft rot, anthracnose, and so on.
Southern Blight
When this disease occurs, water-soaked brown irregular lesions appear on the stem near the roots, the cortex softens and rots, and then white silky mycelium grows and spreads over the soil surface around the roots; later it forms small sclerotia, finally becoming rapeseed-colored, and spreading until the entire base rots and necroses.
Control methods:
1. Before potting, the culture soil should be disinfected. A relatively simple method is to place the culture soil at a temperature of 60°C for 24 hours.
2. Frequently observe the soil surface; when white mycelial threads are found, pick them out and burn them, and scatter some lime powder around the diseased spot for disinfection;
3. In the early stage of the disease, pour 50% carbendazim wettable powder 500-fold solution on the stem base of the plant and the soil around the base, once a week, 2-3 times is sufficient.
Soft Rot
Pathogens often invade through wounds. When the disease occurs, pale yellow water-soaked spots appear on the leaves, later expanding into irregular lesions, causing the leaves to become brown, soft and rotten, with bacterial fluid flowing from the lesions and wounds.
Control methods:
1. Once this disease is found, immediately separate the diseased plant, dig away the culture soil around the plant to expose the affected part, pry open the rotting diseased leaves, scrape off the rotten parts with a sterilized knife, expose it to appropriate sunlight, and keep it ventilated and dry.
2. If many plants have rotted, all diseased tissue must be cut off, soaked in 5% potassium permanganate aqueous solution for 1 hour, rinsed with clear water and dried, smeared with plant ash at the cuts, repotted in new pots, and placed in a ventilated place with moderate temperature.
3. For drug treatment, penicillin, streptomycin, or oxytetracycline plus 4000-****-fold aqueous solution can be sprayed or applied to the lesions, with a certain curative effect.
Anthracnose
This disease mostly occurs in rainy, humid, stuffy and hot seasons, and the affected parts are mostly the leaf tips and leaf margins. In the early stage, moist brown small spots appear on the leaves, then expand into oval and similarly shaped main lesions, with yellow surroundings, and later gradually shrink and dry up. Overly wet potting soil and excessive nitrogen fertilizer make this disease more likely.
Control methods:
1. Give the flowerpot an environment with good ventilation and light, and keep the potting soil only moist; do not water too much or too frequently. Increase phosphorus and potassium fertilizer, and control nitrogen fertilizer.
2. When signs of the disease are found, immediately spray with a solution made from 50% wettable carbendazim powder plus 800-fold water, or a solution of 60% anthracnose thiram plus 1000-fold water, spraying about once every 6 days; 3-5 sprays can be effective. [5]
Common Pests
The common pest of Clivia is scale insects. When pest damage occurs, scale insects often gather on the tender shoot tips of the leaves, suck the leaf sap, and secrete large amounts of pathogens, turning the stems and leaves moldy black, causing sooty mold and making the leaves withered. This insect has strong reproductive capacity and can produce multiple generations in a year; one female adult can often reproduce hundreds of offspring. If control measures are not taken in time, it can cause death.
Control method: Prevention should be the main approach. Usually, frequently observe the plant body, and when pests are found, eliminate them early to prevent spread. To eliminate scale insects, both manual and chemical methods can be used together. If pests are found on only 1 or 2 leaf tips, manual scraping can be done, using a sharpened thin wooden stick or a bamboo skewer to pick off the insects. If a large number of nymphs appear, spray with 25% phosmet emulsifiable concentrate 1000-fold solution, or spray with 40% omethoate emulsifiable concentrate plus 1000-1500-fold water. Generally, 1-2 sprays can kill them.
In addition, note also that: earthworms can also become pests of Clivia. When the Clivia plant is young, its fleshy roots are very tender and weak; if there are earthworms in the potting soil, they often burrow around randomly, injuring the tender roots, destroying the Clivia's function of absorbing nutrients, causing the plant to stop growing and developing or causing root rot.
The control method is: frequently check whether there are round soil granules on the potting soil surface (that is, earthworm excrement). If found, immediately pour a solution made from 50% dichlorvos emulsifiable concentrate plus 1500-2000-fold water. If earthworms are seen burrowing after watering, remove them at once; after one week, do the same again, and the earthworms can be completely eliminated.
Cultivation History of Clivia
In 1823, the Englishman James Bowie discovered Clivia nobilis in the Eastern Cape of South Africa and cultivated it in the private garden of Clive in Northumberland, northern England. In the 1820s, Clivia began to be cultivated in European countries such as Germany, Denmark, and Belgium, and was introduced to Japan in 1854.
Clivia is the city flower of Changchun, Jilin Province, China. In 1932, Clivia was introduced from Japan to Changchun, China, and at first was cultivated only in the Manchukuo court and imperial garden. After Japan's defeat in 1945, Clivia spread from the court to the people for cultivation.
In recent years, China has cultivated more than 160 precious Clivia varieties, and it is a common flower variety in ordinary households. The flowering period is March to April. It likes warm, humid, and semi-shaded environments, is not cold-tolerant, and requires soil with good drainage. There are two propagation methods: division and sowing. Division is carried out in March-April. During the growing period, apply more topdressing; in summer, which is hot and rainy, generally do not fertilize. Clivia has a long flowering period and evergreen leaves, and is most suitable for indoor potted ornamental display.
Main Varieties
Clivia miniata Regel
Clivia nobilis Lindl.
Clivia gardenii Hook
Clivia caulescens R.A.Dyerin
Golden-thread Clivia
White-flowered Clivia