How to Grow Camellias? A Complete Guide to the Growing Environment and Care Essentials
Camellias are a flower variety that many gardening enthusiasts love very much. Because there are so many camellia varieties and their flower colors are bright and colorful, with most petals being double, they are deeply loved by people. Many gardening enthusiasts choose to grow camellias in pots at home, but many of them cannot grow beautiful camellias. So what issues should be noted when growing camellias in pots?
Camellia (Detailed Introduction)
1. Soil is the foundation for the growth of potted camellias, because the camellia root system depends on the soil for growth and development, and the water and nutrients needed for the camellia's life activities are mainly absorbed from the soil. Camellias prefer slightly acidic, humus-rich, loose and airy mountain red (yellow) soil, with a pH value between 5 and 6.5. Alkaline soil or heavy clay soil cannot be used as the potting substrate for camellias. Soil preparation: 50% mountain soil (cultivated red loam soil used for crops), 40% sawdust or edible mushroom residue, 10% cake fertilizer powder or livestock manure and phosphate fertilizer powder. Mix the three well, add an appropriate amount of water, bag and compost. In summer and autumn, more than 20 days; in spring and winter, more than 30 days. This kind of soil is not only loose and airy, but also retains fertilizer and water, and is suitable for the growth and development of camellias.
2. Camellias need suitable light, but are also afraid of high temperatures and direct sunlight. In spring and late autumn, move the camellia to a balcony or ground with more light to receive all-day sunlight, promoting plant growth and development, promoting flower bud differentiation, and making flower buds robust. When summer arrives with the strongest sunlight, move the flowerpot to a shaded, well-ventilated environment for care. It can also be moved to a north-facing balcony or the lower inner side of a south-facing balcony for cultivation. A 75% shade net can also be used to cover the plant from 9 a.m. to 5 p.m. to avoid direct sunlight causing leaf damage or wilting of small plants. If conditions permit, move the camellia under a sun shed to safely pass the summer.
3. Temperature is one of the important conditions for camellia growth. Camellias like warmth, and the most suitable temperature for growth is 18°C to 25°C, with relative humidity of 60% to 65%. For camellia growth, spring shoots generally begin to sprout in mid-to-late March, start budding in April, form terminal buds in mid-to-late May, stop growing, and gradually differentiate into leaf buds or flower buds. From flower bud formation to flowering takes 180 to 240 days. Summer shoots begin to sprout in late July and stop growing in early September. Although camellias are tolerant of low temperatures, if a cold wave invades and the temperature suddenly drops below 0°C, or if it also encounters dry northwest winds, it will cause frost damage to young branches, and flower buds will wither when frostbitten. For this reason, move the flowerpot to a north-facing, south-oriented location for care so that it can safely overwinter.
Camellia (Detailed Introduction)
4. Camellias have many leaves and a large leaf area, so transpiration is fast. Camellias like a relatively humid climate and also like moist soil. Therefore, potted camellias must be given sufficient water. During the spring and autumn growing seasons, water once a day. In summer, especially during the "dog days," water once in the morning and once in the evening every day. If the ground is dry, also water or spray the ground around the flowerpot and the surrounding area once to twice to maintain a certain air humidity, and the plant will grow luxuriantly. At the same time, note that because of frequent watering, and because most households use tap water, over time the soil in the flowerpot will become alkaline. For this reason, when watering, add 0.5% to 1% ferrous sulfate water once a month, or use 5% to 8% edible vinegar liquid to spray the leaves. Camellias like moist soil, but are also afraid of water accumulation in the flowerpot. On rainy days, if water accumulates in the pot, it must be drained promptly to avoid the root system being soaked in water, suffocating and rotting.
5. Camellias are fertilizer-loving flowers. Because the tree is robust, has many leaves, and a relatively long flowering period, they also need a large amount of fertilizer. During fertilization, apply sufficient liquid fertilizer, and combine with repotting to apply sufficient slow-release fertilizer. According to the size of the flowerpot, apply 3 grams to 80 grams of decomposed cake fertilizer powder or dried chicken and duck manure per pot, place it at the bottom of the pot and mix well with the bottom soil. According to the plant's growth stage, apply additional organic fertilizer. Except during the coldest and hottest times in winter and summer, apply decomposed cake fertilizer water once to twice a month. The fertilization method: scrape open the soil at the edge of the pot about 2 fen, pour the liquid fertilizer into the trench, and then cover it with soil to avoid odors. You can also apply decomposed cake fertilizer powder at the edge of the pot and mix it evenly with the potting soil, allowing the flowers to absorb it slowly. Urban gardening enthusiasts can buy special flower fertilizer at flower markets, which is both hygienic and safe. To make camellias grow better, during the peak growth period of camellias, carry out foliar fertilization once to twice a month, spraying the leaves with 0.2% to 0.3% monopotassium phosphate and 1% to 2% plant growth hormone. The principles of fertilization: light rather than heavy, dilute rather than concentrated, less rather than more. You must persist with the method of frequent application of thin fertilizer, and especially do not apply raw fertilizer.
6. Camellias like to grow in an environment with moderately flowing air. They like gentle breezes most. They like the moisture brought by southeast winds, but are afraid of northwest winds and strong winds, which make water evaporate too quickly, causing the camellia's supply and demand to lose balance. The plant and leaves are also easily damaged, causing bud and flower drop. In winter, camellias should be placed in a wind-sheltered, sunny environment for care, with a certain temperature and humidity. In spring and autumn, move the flowerpot to the balcony so that it is ventilated and receives light and sways in the breeze. This not only helps the plant grow well, but also benefits flower bud differentiation and flower bud growth and development, and can also reduce the occurrence of pests and diseases. Years of practice have shown that moderate ventilation and suitable light can play a role in preventing pests and diseases.
Introduction to Camellias and Care Essentials
Camellia (camellia, nai dong, shan chun)
Scientific name: Camellia japonica
Alternative names: Mandala tree, sou chun, shan chun, nai dong, shan cha, wan shan cha, cha hua, yang cha
Family and genus: Theaceae, Camellia
Origin and distribution: The Yangtze River basin and southwestern regions of China; also Japan and the Korean Peninsula. A world-famous ornamental plant and one of China's top ten famous flowers.
Care essentials: Evergreen shrub or small tree. In northern regions, grow in pots with leaf mold or peat soil; in its place of origin, it is often planted in the open ground. Water with soft water, and apply liquid fertilizer once every 2-3 weeks during the growing season. It likes semi-shade and a humid environment. In North China, move it outdoors under a shade shed in summer, with 30%-50% shading. For potted plants in the north, repot once every 2-3 years; overwinter in a cold room, and it can tolerate low temperatures of 2-4°C. There are thousands of cultivated varieties.
Commonly cultivated species in the same genus: Yunnan camellia C. reticulata, sasanqua C. sasanqua, and golden camellia C. chrysantha, etc.
Landscape value: Camellias are shade-tolerant and grow best when placed at the edge of open woodland; planted beside rockeries, they can form miniature rock-and-plant scenes; scattered in groups of three to five near pavilions and terraces, they are especially elegant; if a camellia garden is created, it looks brilliantly brocade-like when in bloom; in a courtyard, a few can be scattered at one corner of the courtyard wall, naturally unrestrained; if paired with rhododendrons and magnolias, then when in bloom, red and white alternate and vie for beauty; in forest parks, they can also be scattered or planted in groups along forest edges and roadsides with some robust varieties, adding much color to the mountain forest when in bloom. Camellias are suitable for potted ornamental display and can achieve good effects when placed at entrance halls, conference rooms, and public places; planted on home balconies and in front of windows, they show abundant spring vitality.
Propagation: cuttings, layering, and grafting.
Light: Needs light, slightly shade-tolerant (semi-shade).
Water: Grows in moist soil.
Temperature: Strong cold resistance, can tolerate low temperatures below -10°C.
Relative humidity: Moderate relative humidity, 50%-60%.
Care and Management Methods for Home Potted Camellias
Care and Management Methods for Home Potted Camellias
First prohibition: fertilizing at the early sprouting stage
During the spring branch and leaf growth period, applying nitrogen-based fertilizer is a habitual idea and practice of quite a few camellia enthusiasts. They believe this can provide sufficient nutrition for camellias, so that vegetative growth can flourish. People who hold this view are not saying that applying nitrogen fertilizer is wrong, but that the timing of fertilization is inappropriate. In fact, the correct timing for fertilization should be during the period when the camellia's mass flowering is nearing its end and the new buds have not yet begun to sprout. Because flowering consumes most of the plant's nutrients, and sprouting new buds also requires a certain accumulation of nutrients, and at this time new roots are about to grow, fertilizing at this time is just right. It not only replenishes what flowering consumed, but also provides a guarantee for the sprouting and growth of new buds; another important point is that camellias generally do not go dormant after flowering, and some varieties directly send out branches and sprout leaves after flowering. So using the phrase "timely help in the snow" to describe fertilizing at this time is most fitting. Fertilizing at the early sprouting stage is not suitable because the newly grown tender fleshy fibrous roots cannot withstand even a light fertilizer application, let alone the fact that inexperienced growers find it hard to correctly control fertilizer concentration, and the slightest carelessness can easily burn the roots. The beautiful wish to supplement the plant with fertilizer backfires because the fertilization timing is wrong. Therefore, during the spring sprouting period, fertilization must be timed properly so that the plant can grow normally.
Second prohibition: applying concentrated fertilizer during the leaf-unfolding period
Applying concentrated fertilizer during the leaf-unfolding period seems contradictory to the earlier statement that fertilizing at the early sprouting stage is inappropriate, but it is not. There are mainly two meanings here: first, it means that after the camellia's spring mass flowering period is nearing its end and the new buds have not yet sprouted, after this fertilization, it is best to wait until the new leaves have unfolded and then some time has passed before fertilizing again, generally 10-15 days, specifically applying nitrogen-based fertilizer once or twice more before the new leaves finish expanding. The concentration should be dilute when applying. Return water the next day after application. After May, nitrogen fertilizer can no longer be applied. The purpose of this fertilization is to accelerate the maturity of the new leaves and prepare for the next stage of flower bud development. Second, it means that both the pre-sprouting fertilization and the subsequent fertilization are best applied as plant-based fertilizers; for example, applying decomposed rapeseed cake, soybean cake, peanut cake, etc., which not only contain a large amount of nitrogen but also a certain amount of phosphorus, and more valuably, have a pH value of 6 or below, belonging to acidic fertilizers. When applied dry, the fertilizer can slowly volatilize; when applied in water, it is a fast-acting fertilizer. It can be used both as a base fertilizer and as a top dressing. Plant-based fertilizers are mild in nature and are quite suitable for camellias, which are not tolerant of heavy fertilizer. During the leaf-unfolding period, applying "concentrated fertilizer" is most taboo. This especially refers to poultry and livestock manures, such as pigeon, chicken, and duck manure. These fertilizers are strong in nature, and camellias are prone to fertilizer damage after application. This is even more true during the leaf-unfolding period. Symptoms of fertilizer damage include blackening of the leaf tips of new leaves, wrinkling, greasy shine, spots, and streaky spots (spots and streaky spots are actually fertilizer damage produced by concentrated fertilizer on new leaves), small unfolding degree, and difficulty in extending. In particular, blackened leaf tips and spots and streaky spots on new leaves are the primary basis for diagnosing fertilizer damage. The phenomenon occurs on the leaves, but the root cause is in the roots. This is the burning of the newly grown fibrous roots specifically responsible for absorption. The development of new roots is hindered, and one can imagine that the growth and development of new leaves will be greatly reduced. A leaf's normal physiological lifespan is 2 to 3 years. These poorly developed and oddly shaped leaves are detrimental to ornamental value in every respect, so the importance of avoiding concentrated fertilizer during the leaf-unfolding period also lies in this.
Third prohibition: spraying urea or Bordeaux mixture before new leaves mature
The maturation period of new leaves is generally from late March, when they begin to sprout, to around early May, when expansion stops (the timing varies by region depending on temperature), lasting a little more than one month. During this period, based on past cultivation and management lessons, spraying urea or Bordeaux mixture on the leaves before the new leaves mature is most taboo. Urea is an inorganic alkaline fertilizer and is mostly applied dry or broadcast in flower cultivation. When applied to potted flowers, it must be diluted to a concentration below 0.1%, otherwise it will cause the plant to dehydrate and die. Bordeaux mixture is a homemade fungicide, prepared just before use from quicklime and copper sulfate. Its efficacy lasts about 2 weeks, providing protection and sterilization, preventing the invasion of pathogens and controlling the spread of pathogens after disease onset. Because of insufficient understanding of the fertilizer properties of urea and the medicinal properties of Bordeaux mixture, some simply believed that camellias could be provided with fast-acting nitrogen fertilizer in spring when they send out branches and unfold leaves, accelerating the growth and development of new leaves, while also protecting the new leaves from pests and diseases, and so sprayed urea and Bordeaux mixture on the leaves one after the other. Little did they know that urea has strict requirements for dilution concentration, and similarly Bordeaux mixture has several ratios depending on different flower leaves and temperatures, including equal-strength, double-strength, and half-strength formulations. As a result, after spraying urea, the new leaves fell one after another, eventually leaving bare stems, and the plant soon died. After spraying Bordeaux mixture, the new leaves scorched, shrank, and wrinkled. Although they did not die, the normal growth of the plant was seriously affected. The reason is that after spraying urea (especially if the concentration was not well controlled), fertilizer damage is very likely to occur. The cell sap in the plant body undergoes reverse osmosis, causing the plant to dehydrate and die. After spraying Bordeaux mixture (referring to the equal-strength formulation, with 1 part copper sulfate, 1 part quicklime, and 140-180 parts water, stirred), pesticide damage occurs due to the action of copper sulfate. The harm is especially severe to tender new leaves. Therefore, the author reminds all enthusiasts that before new leaves mature (that is, before expansion is completed), do not spray urea or Bordeaux mixture (even after new leaves mature and age, for safety's sake it is best not to spray them on the leaves). Instead, use relatively mild plant-based fertilizers, strengthen routine care and management of the plant, and importantly, cultivate robust plants. Only in this way can pest and disease invasion and infection be prevented and reduced. Make the plant's vegetative growth vigorous and prepare for the next stage of flower bud development.
Fourth prohibition: incomplete watering in summer
Camellias do not go dormant in summer, and the flower buds are in their development period. Also, because summer is hot, dry, and rain-scarce, healthy branches that do not bear flower buds will still sprout a small amount of summer shoots, so in summer, incomplete watering (that is, wet on top and dry below) is most taboo. For precious camellia varieties, households generally prefer potted cultivation. Potted plants have limited soil and cannot compare with open-ground planting. Compared with the two, a notable characteristic of potted cultivation is its small water-holding capacity. In hot, high-temperature summers, evaporation is fast, metabolism is vigorous, and the potting soil dries quickly. If watering is incomplete at this time, the lower roots are in a state of water shortage, and the root system will gradually shrink and dry up, losing the function of absorbing nutrients and water. After the root system is damaged, the upper leaves of the plant will slowly dry up and fall off from bottom to top. This is the main sign of water shortage in the plant. If discovered in time, it can still be saved. If too much time passes, when the leaves fall off at a touch, and the newly sprouted leaves at the top of the branches hang down without vitality, it is mostly because the roots have been deprived of water for too long and the root system, especially the newly grown fibrous roots, has shrunk and lost vitality. At this point, nothing can be done, and one can only give up. To judge whether watering is normal, just observe the leaves. If the leaves face upward and do not droop even in sunlight, generally the water supply and demand in the potting soil are reasonable. Two factors should be excluded here: (1) If fertilizer is applied as usual in summer and fertilizer damage occurs, the roots are damaged. Generally, fertilization is avoided in summer, so this factor can be excluded. (2) The other is that without timely shading under strong light, the leaves sometimes temporarily wilt downward. If moving them to a shaded place allows them to recover, then it is not caused by water shortage, but by an imbalance between root absorption and excessive transpiration from the upper leaves. Excluding the above two factors, downward-facing leaves are the initial response to incomplete watering. If attention is paid at this time and water is promptly applied thoroughly until it flows out from the bottom of the pot, the plant can slowly recover its vitality, and its physiological functions can return to normal. Therefore, in summer, water thoroughly once in the morning. If dryness is found in the evening, water again as a supplement. Even around noon in hot weather, if individual plants are found to be especially dry, one should break the rule that watering is not allowed at noon, and not only water but water thoroughly. Only the method of watering should be particular: "First move it to a shaded place, spray water on the branches and leaves, and when the stems and leaves stand up, then water thoroughly." In summer, regardless of whether you water once a day, twice a day, or multiple times, each watering must be thorough. This is the voice of experience, and there are past lessons to serve as warnings.
Fifth prohibition: frequently changing positions
Flowers, like people, are living beings and need careful care. But there is a limit to everything. If you love flowers too much, it will backfire. Some people casually move flowerpots around, shifting them to several places a day, making the flowers constantly adapt to the environment and disrupting normal growth patterns. Over time, as the flowers are tossed back and forth, they either become wilted and lifeless, or are left barely surviving, and it would be strange if they did not die. From the author's caregiving practice, camellia care requires a relatively stable growing environment (not only camellias; other flowers also have this requirement). After choosing a position and placing it, in general do not easily move it (unless severe weather forces you to move it). Camellias cared for in a stable environment naturally grow normally. Conversely, if you put it on the balcony today, place it indoors tomorrow, put it in the sun when you want it to sunbathe, and move it to a dark place when the temperature is too high, then in fact camellias most taboo sudden rises and drops in temperature and sudden strong or weak changes in light, forcing them to constantly adapt to the environment. They will naturally feel exhausted and grow poorly. To use an analogy: this is like running. If you run fast for a while and slow for a while, the person feels especially strained. If you always run at a uniform speed, you can instead keep going. The principle is the same. There is another point you may not have noticed: when you frequently move potted flowers, you cannot always keep the camellia's placement exactly the same as before, and its orientation will inevitably change frequently as well. In this way, the original sunny side may become the shady side, and the shady side becomes the sunny side (the sunny side refers to the side that can receive sunlight; the shady side is the opposite). Under strong light, it may not adapt and the leaves may be scorched. In fact, if camellias are to be acclimated to light, this should begin slowly in spring, allowing them to receive sunlight and adapt to growing in sunlight. If the sunny and shady sides are suddenly switched, especially under strong light, the leaves will naturally be scorched and growth will suffer. For camellia care, it is best to have "two fixed aspects," namely a fixed position and a fixed orientation (of course, this fixation is relative). To prevent the camellia from possibly growing toward one side after the orientation is fixed, after some time you can appropriately change the direction in the same place again, but note that the interval cannot be too short; one month is good. Reduce the impact to the minimum possible while also allowing the entire branches and leaves of the camellia to receive light from all directions, so it grows naturally evenly and its ornamental value is improved. Camellia care should be relatively fixed, and frequently changing positions should be avoided. This is an important move for growing camellias well, and it has been confirmed by practice.
Sixth prohibition: spraying water on branches and leaves during the transition from spring to summer
Spraying water on branches and leaves seems to most people an extremely ordinary thing. Many people use spraying water to replace washing leaves or replace watering. In summer and autumn, to satisfy the camellia's habit of liking humidity, they also often use spraying to lower temperature, raise humidity, and improve the local microclimate. But in spring it should be used cautiously, especially during the late spring and early summer period. There are mainly two reasons for this consideration: (1) As the folk saying goes, "Business in spring is truly hard to do, with luggage on one end and goods on the other," which refers to spring having a lot of rain. It rains whenever it wants, and in a single day it can rain intermittently several times. Air humidity itself is already very high. Late spring and early summer is also the plum rain season in the south, and the air humidity can be said to be already saturated. (2) Most camellia diseases occur frequently during the transition from spring to summer, when it is hot and humid. There are basically two diseases affecting camellias: anthracnose and brown spot. Brown spot is also called black spot. These two diseases are characterized by beginning to occur in May and June, peaking in July and August, and stopping after September.
For these two diseases, when the temperature rises to around 20°C, the pathogens produce conidia, which spread with wind and rain, and the pathogens invade the leaf tissue. Through repeated infection, the disease intensifies and spreads. Generally, poor ventilation, insufficient light, improper fertilizer and water, and weak plant growth promote disease occurrence. In addition to the above reasons, those who like to use spraying water to replace washing leaves or replace watering should at least stop during this period, otherwise they undoubtedly open the door wide for pathogen invasion and, to some extent, add fuel to the fire. The author has experience and lessons, and hopes growers will pay attention and take note. Therefore, avoiding spraying water on branches and leaves in spring is a powerful measure to reduce disease. Of course, environmental ventilation and strengthening light must also closely follow. Only by cultivating healthy plants, plus scientific management, can the plant have strong roots and lush leaves.
Seventh prohibition: fertilizing during three periods
The three periods when camellias should not be fertilized are: "summer fertilization, pre-flowering fertilization, and winter fertilization." Although camellias do not go dormant in summer, the weather is hot, the climate is dry, and the water in the potting soil evaporates quickly. Fertilizing easily increases fertilizer concentration and can burn the root system. This is the reason why fertilization is not suitable in summer. The flowering period of camellias is generally mostly in late winter and early spring. Although flowering requires a large amount of nutrients, the focus should be placed on fertilization in spring and autumn. Fertilizing before flowering often "pushes off" the large flower buds about to open, causing bud and flower stagnation. Or after the flowers open, the petal tips turn black, the petals unfold only a little, and cannot open fully in all directions. Camellias have the habit of going dormant in winter. At this time growth stops, and fertilization has no effect on them. Contrary to the above, camellia fertilization must grasp three key periods: (1) Apply sprouting fertilizer in February-March. That is, during the period after flowering and before sprouting, mainly nitrogen fertilizer. (2) Apply flower bud fertilizer in May-June, mainly phosphorus fertilizer. (3) Apply flower bud fertilizer in October-November, a compound fertilizer of nitrogen, phosphorus, and potassium. After the flowers show color, it can no longer be applied (that is, after December, once winter begins, it can no longer be applied). If camellia fertilization can grasp the principle of three applications and three non-applications, with plant-based fertilizers as the main type and poultry manure fertilizers applied sparingly or not at all, and with application as dilute as possible, preferring multiple applications, then this is the operational key to fertilization. It can be said to be a fertilization method groped for through long-term camellia care of "learning from one's mistakes."
Eighth prohibition: grafting without purpose or plan
Camellia grafting generally mostly refers to multi-variety grafting. All multi-variety grafting faces the problem of how to select and match scions. Although the choice of scions is governed by each person's interests and hobbies, mindsets such as pure imagination and doing as one pleases should not be adopted. We should take a scientific attitude, make correct choices based on variety resources, and then make reasonable combinations according to the operator's personal preferences, so that the grafted camellia can achieve the expected results. Below are several choices for readers' reference, each with advantages and disadvantages. One must maximize strengths and avoid weaknesses, have some focus, and turn unfavorable factors into favorable ones in order to gain something and achieve success.
(1) Choose varieties with similar plant types and growth vigor: If the selected varieties have different growth vigor, some will inevitably sprout early and some late. Early-sprouting varieties have sufficient nutrients, good growth, and many new shoots, while late-sprouting varieties become weak because their nutrients are exhausted by the earlier ones. Varieties with different plant types grafted together may be upright or spreading. So if not considered carefully in advance, the plant type will become chaotic and detrimental to ornamental value.
(2) Choose varieties with the same flowering period: With this consideration, when flowering, the effect of multiple colors and multiple forms on one tree can be achieved. But achieving such an effect is not as easy as imagined. If all retain flower buds, the mother plant's nutrients will inevitably be exhausted, and growth in the following years will not be vigorous. The correct approach should be to let different varieties open year by year in batches and stages. Those with vigorous growth open that year, and those with weak growth open the next year. This helps the mother plant recover and preserve its vitality.
(3) Choose varieties with inconsistent flowering periods: The purpose is to let the mother plant's flowering open batch after batch, which in fact also prolongs the flowering period, which is what we hope for. But this can only be possible if the mother plant is strong and vigorous. Otherwise, only the early-flowering varieties can be allowed to open. Late-flowering varieties often cannot open due to insufficient nutrients and die in the bud. Flower and bud drop is the inevitable result. Therefore, this kind of grafting places certain demands on the mother plant. If these cannot be met, it can only be allowed to focus on vegetative growth, so that it conserves strength and blooms again next year or the year after.
(4) Choose a reasonable combination of flower colors and flower forms: The choice of matching flower colors and flower forms can be determined entirely according to individual preferences. Some like single petals, and some like double petals. Some like red, and some prefer white. This cannot be forced. If varieties of the same color are chosen, then at flowering time it may be a blaze of red or a tree of silver adornment, and the effects are both spectacular. If someone thinks one variety is too monotonous, they can graft various varieties crosswise onto one tree, and at the appropriate time achieve a colorful effect.
(5) Choose different varieties of the same tree species: The purpose of doing this is to coordinate the tree vigor and make it beautiful. If camellia and sasanqua are grafted respectively onto one tree, the former has long branches and large leaves, while the latter has fine branches and small leaves. It then looks somewhat incongruous, and the flower forms also vary in size. In no respect is this desirable.
Therefore, multi-variety grafting of camellias must be planned in advance and considered comprehensively. Do not act on a sudden impulse or arbitrarily. Otherwise, the expected visual effect will not be achieved, and it will only waste time and effort with no reward.
Pot Selection and Soil Use
1. Pot selection should ensure that the plant and pot are moderate in size relative to each other. Do not use a small pot for a large seedling. Generally, 2- to 3-year-old seedlings can use 4-inch to 5-inch clay pots. It is best not to use porcelain pots, because they have poor air permeability and easily accumulate water, causing root rot. If there are many seedlings, a 7-inch to 8-inch clay pot can be used to plant 2 to 3 plants together in one pot. After one or two years, divide them into separate pots. Camellias like to grow in slightly acidic soil. For the soil, use 4 parts yellow soil, 3 parts leaf mold, and 3 parts sand, mix well, and use. First place tiles at the bottom of the pot, then fill in about one inch of coarse sand to facilitate drainage. Then add a layer of mixed soil. Plant the plant leaning to one side of the pot. Planting against the side of the pot is better than planting in the middle, because the soil at the edge of the pot always dries first, making it less likely to cause root rot from water accumulation, and roots develop quickly and survival is easy. Cover with soil until the topmost layer of roots is slightly higher, and it need not be too deep. Then lift the pot and gently shake it a few times so that the soil and roots are in close contact, water thoroughly, and place in a cool place. Every morning and evening, use a fine-spout sprayer to spray water on the leaves to keep them moist. After half a month, it can be moved outdoors for normal care and management.
2. Fertilizer and water management. Camellia leaves are leathery and cannot reflect the plant's water needs by wilting. Therefore, one cannot adopt the method of watering only after the potting soil has dried completely. Water must be applied immediately when the potting soil is 50%-60% dry, with the surface slightly whitish or with tiny cracks. Water slowly so it penetrates, until water flows out from the bottom of the pot. In summer, watering can be combined with spraying water on the leaves. During the plum rain season, accumulated water in the pot should be drained promptly to avoid root rot caused by poor air permeability in the potting soil. Balconies have strong wind, dryness, and much dust, so it is necessary to frequently spray water on the leaf surfaces and around the pot to wash off dust, increase humidity, and clean the leaves so that leaf photosynthesis works well. Camellias like fertilizer but are afraid of concentrated fertilizer, so apply thin fertilizer frequently. The fertilization method is: in spring and autumn, apply fertilizer at the roots; in summer and winter, apply foliar top dressing. Before April, apply decomposed cake fertilizer plus a small amount of ferrous sulfate to prevent the potting soil from becoming alkaline and causing yellowing leaves. At the same time, alternately apply 2‰ urea to promote more spring buds, strong spring shoots, and enhanced reproductive capacity. Before each application, loosen the potting soil so that the fertilizer water penetrates evenly and the roots can absorb nutrients as quickly as possible. After April and before early July, and throughout autumn, switch to applying fish offal water with higher potassium and phosphorus content and 3‰ monopotassium phosphate to ensure the various nutrients needed for flower bud differentiation during the reproductive period and the flower bud stage. Fertilizer should be applied once a week. In summer and winter, do not apply root fertilizer; instead apply foliar fertilizer. While spraying water on the leaves, use a 2‰ monopotassium phosphate aqueous solution for foliar top dressing, generally twice a week. It is best to spray the undersides of the leaves. Spray in the morning or evening in summer, and at noon on sunny days in winter.
3. Light control. Balcony light is generally relatively strong. For camellias, which like semi-shade, controlling light in summer is key. Summer is also the flower bud stage of camellias. If potted flowers are moved, it will disturb the growing environment and light-receiving side they have already adapted to, affecting flower bud quality and causing flower buds to be small, unable to produce large and brilliant flowers. The best method is to place some taller light-loving flowers or tree stumps on the sunny side of the potted flowers as a screen. This can both shade light and not block dew. After the hot summer passes, the potted flowers can be allowed to receive sufficient sunlight. Camellias are generally relatively cold-tolerant. In most regions of our country, as long as the temperature is not lower than -5°C, they can safely overwinter outdoors (except in the cold northern regions).
4. Branch thinning and pruning. Camellias generally do not need pruning. Only after flowering should the faded flowers be cut off promptly, and at the same time cut off weaker diseased branches and some inner branches and overly dense branches that affect the plant's graceful posture. But by no means should large-scale truncation be used just because the plant is relatively tall. This easily damages its vitality and causes the plant to die. Bud thinning should be timely. Too early easily affects the buds to be kept; too late consumes more nutrients. The best time is when the buds are slightly larger than soybeans. For each branch, keeping only 1 to 2 buds is enough. For 2- to 3-year-old small seedlings, at most only 3 to 4 can be kept. Try to retain the terminal buds and remove all the rest. If careful care and management are carried out according to the above points, then on a balcony one can likewise cultivate camellias with abundant flowers and lush leaves.
Potted Camellia Techniques
1. Suitable soil. Soil is the foundation for the growth of potted camellias, because the camellia root system depends on the soil for growth and development, and the water and nutrients needed for the camellia's life activities are mainly absorbed from the soil. Camellias prefer slightly acidic, humus-rich, loose and airy mountain red (yellow) soil, with a pH value between 5 and 6.5. Alkaline soil or heavy clay soil cannot be used as the potting substrate for camellias. Soil preparation: 50% mountain soil (cultivated red loam soil used for crops), 40% sawdust or edible mushroom residue, 10% cake fertilizer powder or livestock manure and phosphate fertilizer powder. Mix the three well, add an appropriate amount of water, bag and compost. In summer and autumn, more than 20 days; in spring and winter, more than 30 days. This kind of soil is not only loose and airy, but also retains fertilizer and water, and is suitable for the growth and development of camellias.
2. Moderate light. Camellias need suitable light, but are also afraid of high temperatures and direct sunlight. In spring and late autumn, move the camellia to a balcony or ground with more light to receive all-day sunlight, promoting plant growth and development, promoting flower bud differentiation, and making flower buds robust. When summer arrives with the strongest sunlight, move the flowerpot to a shaded, well-ventilated environment for care. It can also be moved to a north-facing balcony or the lower inner side of a south-facing balcony for cultivation. A 75% shade net can also be used to cover the plant from 9 a.m. to 5 p.m. to avoid direct sunlight causing leaf damage or wilting of small plants. If conditions permit, move the camellia under a sun shed to safely pass the summer.
3. Suitable temperature. Temperature is an important condition for the physiological activities of camellias. Camellias like warmth, and the most suitable temperature for growth is 18°C to 25°C, with relative humidity of 60% to 65%. For camellia growth, spring shoots generally begin to sprout in mid-to-late March, start budding in April, form terminal buds in mid-to-late May, stop growing, and gradually differentiate into leaf buds or flower buds. From flower bud formation to flowering takes 180 to 240 days. Summer shoots begin to sprout in late July and stop growing in early September. Although camellias are tolerant of low temperatures, if a cold wave invades and the temperature suddenly drops below 0°C, or if it also encounters dry northwest winds, it will cause frost damage to young branches, and flower buds will wither when frostbitten. For this reason, move the flowerpot to a north-facing, south-oriented location for care so that it can safely overwinter.
4. Suitable humidity. Camellias have many leaves and a large leaf area, so transpiration is fast. Camellias like a relatively humid climate and also like moist soil. Therefore, potted camellias must be given sufficient water. During the spring and autumn growing seasons, water once a day. In summer, especially during the "dog days," water once in the morning and once in the evening every day. If the ground is dry, also water or spray the ground around the flowerpot and the surrounding area once to twice to maintain a certain air humidity, and the plant will grow luxuriantly. At the same time, note that because of frequent watering, and because most households use tap water, over time the soil in the flowerpot will become alkaline. For this reason, when watering, add 0.5% to 1% ferrous sulfate water once a month, or use 5% to 8% edible vinegar liquid to spray the leaves. Camellias like moist soil, but are also afraid of water accumulation in the flowerpot. On rainy days, if water accumulates in the pot, it must be drained promptly to avoid the root system being soaked in water, suffocating and rotting.
5. Appropriate nutrients. Camellias are fertilizer-loving flowers. Because the tree is robust, has many leaves, and a relatively long flowering period, they also need a large amount of fertilizer. During fertilization, apply sufficient liquid fertilizer, and combine with repotting to apply sufficient slow-release fertilizer. According to the size of the flowerpot, apply 3 grams to 80 grams of decomposed cake fertilizer powder or dried chicken and duck manure per pot, place it at the bottom of the pot and mix well with the bottom soil. According to the plant's growth stage, apply additional organic fertilizer. Except during the coldest and hottest times in winter and summer, apply decomposed cake fertilizer water once to twice a month. The fertilization method: scrape open the soil at the edge of the pot about 2 fen, pour the liquid fertilizer into the trench, and then cover it with soil to avoid odors. You can also apply decomposed cake fertilizer powder at the edge of the pot and mix it evenly with the potting soil, allowing the flowers to absorb it slowly. Urban gardening enthusiasts can buy special flower fertilizer at flower markets, which is both hygienic and safe. To make camellias grow better, during the peak growth period of camellias, carry out foliar fertilization once to twice a month, spraying the leaves with 0.2% to 0.3% monopotassium phosphate and 1% to 2% plant growth hormone. The principles of fertilization: light rather than heavy, dilute rather than concentrated, less rather than more. You must persist with the method of frequent application of thin fertilizer, and especially do not apply raw fertilizer.
6. Suitable environment. Camellias like to grow in an environment with moderately flowing air. They like gentle breezes most. They like the moisture brought by southeast winds, but are afraid of northwest winds and strong winds, which make water evaporate too quickly, causing the camellia's supply and demand to lose balance. The plant and leaves are also easily damaged, causing bud and flower drop. In winter, camellias should be placed in a wind-sheltered, sunny environment for care, with a certain temperature and humidity. In spring and autumn, move the flowerpot to the balcony so that it is ventilated and receives light and sways in the breeze. This not only helps the plant grow well, but also benefits flower bud differentiation and flower bud growth and development, and can also reduce the occurrence of pests and diseases. Years of practice have shown that moderate ventilation and suitable light can play a role in preventing pests and diseases.
Fertilization Tips for Potted Camellias
Camellia fertilization should be carried out selectively according to different growth stages of the camellia. During the growing period, camellias need top dressing, and fast-acting liquid fertilizer and chemical fertilizer are suitable. During the stage of sending out branches and leaves, apply nitrogen fertilizer or a mixed fertilizer mainly based on nitrogen. Before flower bud differentiation, flower bud formation, enlargement, and flowering, phosphorus fertilizer or a mixed fertilizer mainly based on phosphorus is needed. In autumn and winter, mixed fertilizers mainly based on phosphorus and potassium are most suitable.
(1) Nitrogen fertilizer to promote spring shoots
Camellias generally begin to sprout spring shoots at around 18°C. At this time, apply bud-promoting fertilizer mainly based on nitrogen, once every 10 days, until the spring shoots begin to lignify. If conditions permit, a diluted mixed solution of 1000 times monopotassium phosphate, about 1% urea, and about 300 times rice vinegar can also be sprayed on the leaves at the same time. After multiple root and foliar sprays, the spring shoots will grow very luxuriantly, the leaves can extend to the maximum, and the branches can accumulate abundant nutrients, creating good conditions for flower bud differentiation.
(2) Increase application of phosphorus and potassium fertilizer to promote flower bud differentiation and form flower buds
After the camellia spring shoots have fully grown and entered lignification, there will be a short semi-dormant period. At this time, the camellia shifts from the vegetative growth stage to reproductive growth, and flower buds begin to differentiate. If you want camellias to form more buds, apply more phosphorus and potassium fertilizer, and do not apply or apply little nitrogen fertilizer. If small camellia plants are mainly being grown to develop the plant, then still mainly use nitrogen fertilizer, and do not apply or apply little phosphorus fertilizer. About every 10 days, spray the leaves with a diluted mixed solution of 1000 times monopotassium phosphate, a small amount of borax, and rice vinegar. This can both control excessive growth of camellia branches and promote and shorten the time of flower bud differentiation, which is beneficial to flower bud formation.
(3) Do not fertilize in midsummer, and even more do not apply concentrated fertilizer
In midsummer, the weather is hot, and camellias grow slowly or fall into a semi-paused state. At this time, fertilization is not suitable, and especially do not apply concentrated fertilizer. If the soil is poor, a slightly diluted liquid fertilizer can be applied along with watering to improve the soil.
(4) In autumn, appropriately apply mixed fertilizer mainly based on phosphorus and potassium fertilizer
In autumn, the sky is high and the air is crisp, which is a period of nutrient accumulation for camellia plants. In order to overwinter safely, apply a mixed fertilizer mainly based on phosphorus and potassium fertilizer once every half month, combined with foliar spraying, to promote robust plant growth and improve the cold resistance of camellias.
(5) In winter, apply dilute phosphorus-potassium liquid fertilizer
In deep winter, camellias enter a semi-dormant period. When camellias are brought indoors or into cellars, vegetative growth has entered dormancy, and not much fertilizer is needed. But their reproductive growth has not completely stopped. They are in the season of flowering or preparing to flower, so dilute phosphorus-potassium liquid fertilizer should be applied along with watering. Absolutely avoid concentrated fertilizer.
Applying concentrated fertilizer during the leaf-unfolding period
Applying concentrated fertilizer during the leaf-unfolding period seems contradictory to the earlier statement that fertilizing at the early sprouting stage is inappropriate, but it is not.
There are mainly two meanings here: first, it means that after the camellia's spring mass flowering period is nearing its end and the new buds have not yet sprouted, after this fertilization, it is best to wait until the new leaves have unfolded and then some time has passed before fertilizing again, generally 10-15 days, specifically applying nitrogen-based fertilizer once or twice more before the new leaves finish expanding. The concentration should be dilute when applying. Return water the next day after application. After May, nitrogen fertilizer can no longer be applied. The purpose of this fertilization is to accelerate the maturity of the new leaves and prepare for the next stage of flower bud development.
Second, it means that both the pre-sprouting fertilization and the subsequent fertilization are best applied as plant-based fertilizers; for example, applying decomposed rapeseed cake, soybean cake, peanut cake, etc., which not only contain a large amount of nitrogen but also a certain amount of phosphorus, and more valuably, have a pH value of 6 or below, belonging to acidic fertilizers. When applied dry, the fertilizer can slowly volatilize; when applied in water, it is a fast-acting fertilizer. It can be used both as a base fertilizer and as a top dressing. Plant-based fertilizers are mild in nature and are quite suitable for camellias, which are not tolerant of heavy fertilizer. During the leaf-unfolding period, applying "concentrated fertilizer" is most taboo. This especially refers to poultry and livestock manures, such as pigeon, chicken, and duck manure. These fertilizers are strong in nature, and camellias are prone to fertilizer damage after application. This is even more true during the leaf-unfolding period. Symptoms of fertilizer damage include blackening of the leaf tips of new leaves, wrinkling, greasy shine, spots, and streaky spots (spots and streaky spots are actually fertilizer damage produced by concentrated fertilizer on new leaves), small unfolding degree, and difficulty in extending. In particular, blackened leaf tips and spots and streaky spots on new leaves are the primary basis for diagnosing fertilizer damage. The phenomenon occurs on the leaves, but the root cause is in the roots. This is the burning of the newly grown fibrous roots specifically responsible for absorption. The development of new roots is hindered, and one can imagine that the growth and development of new leaves will be greatly reduced. A leaf's normal physiological lifespan is 2 to 3 years. These poorly developed and oddly shaped leaves are detrimental to ornamental value in every respect, so the importance of avoiding concentrated fertilizer during the leaf-unfolding period also lies in this.
Seven Prohibitions in Camellia Care
Introduction: Camellias are plants very easily seen in ordinary gardens. Because the dark green leaves are also very beautiful, the leaves alone can also be used as a foil for other flowers. But the disadvantage is that the flowers fall easily. One can often see flowerbeds or potted plants filled with primroses. Do not water too much. Be careful not to let the roots rot.
Care essentials: Seven prohibitions in camellia care. First prohibition: fertilizing at the early sprouting stage. Second prohibition: applying concentrated fertilizer during the leaf-unfolding period. Third prohibition: spraying urea or Bordeaux mixture before new leaves mature. Fourth prohibition: incomplete watering in summer. Fifth prohibition: frequently changing positions. Sixth prohibition: spraying water on branches and leaves during the transition from spring to summer. Seventh prohibition: fertilizing during three periods.
Care and management placement location: Camellias should be placed in a warm, humid, ventilated, and light-transmitting place. In spring, there should be sufficient light. In summer, pay attention to shading, avoiding direct sunlight and western exposure. If placed on a balcony, they are often sunburned to death with a moment's carelessness. In winter, they should be placed indoors with a room temperature above 3°C.
Fertilizing: Camellias love fertilizer. When potting, be sure to place a base fertilizer in the potting soil, mainly phosphorus and potassium fertilizers. Fertilizers applied include decomposed bone meal, hair, chicken feathers, rice hull ash, poultry manure, and superphosphate. Normally, do not apply too much fertilizer. Generally, apply 2 to 3 times of dilute fertilizer water between April and May after flowering, and apply one application of slightly stronger liquid fertilizer in November in autumn. When applying fertilizer, note that the proportion of phosphorus fertilizer should be slightly larger to promote abundant flowers and vivid colors.
Watering: The cultivation of camellia bonsai should maintain the soil in a moist state, but it should not be too wet, to prevent alternating dry and wet conditions. Generally, in spring, water appropriately more to promote budding and shoot growth; in summer, insist on watering in the early morning and evening, preferably spraying water on the leaf surfaces so the leaves are thoroughly wet. Do not use a strong stream to water directly or flood the pot, and do not water with hot water. Avoid watering around midday when temperatures are high; in autumn, water moderately; in winter, water around midday, and spray water once every two or three days.
Repotting: Camellia bonsai can be repotted once every 1 to 2 years. The new pot should be one size larger than the old pot to facilitate the spreading and development of the root system. The best time for repotting is in April in spring, and autumn is also acceptable. Along with changing the soil, appropriately remove part of the compacted old soil, replace it with fertile, loose new soil, and place a base fertilizer at the same time.
Pruning: Camellias grow relatively slowly and should not be pruned excessively. Generally, it is enough to cut off leggy branches that affect the tree shape, as well as diseased, pest-damaged, and weak branches. If there are too many flower buds on each branch, thin the flowers to keep only 1 to 2, and maintain a certain distance between them; remove the rest early to avoid consuming nutrients. In addition, promptly remove flowers that are close to withering, which can also reduce nutrient consumption, help the plant grow robustly, and form new flower buds.
Pest and disease control: The main diseases of camellias include black mold and anthracnose, which can be controlled by spraying 0.5-degree Bordeaux mixture. The main pest is the tea shoot moth. The control method is to cut off infested shoots, preferably from April to June. It can also be controlled by spraying methamidophos at a 2000-fold dilution. The best time to spray is at the end of March and the beginning of April, when the damage from overwintering larvae is relatively light. When spraying, the leaves and tender shoots must be sprayed until wet.