How to Grow Ranunculus? A Detailed Explanation of Key Cultivation Techniques
Ranunculus has a delicate and graceful plant form with rich, brilliant flower colors, and is a perennial herbaceous flower. It is an excellent potted ornamental plant with high ornamental and commercial value. Ranunculus is also edible and is a very good vegetable; it can supplement the nutrients the human body needs and is a food ingredient with extremely high nutritional value. Below, let's discuss the cultivation techniques for ranunculus.
1. Germination: At 5-20°C, bury the ranunculus tubers in a substrate mixed with vermiculite and perlite at a ratio of 4:1, keep the substrate humidity at 80-90%, and after 10-20 days, the ranunculus will sprout.
2. Cultivation: Transplant the ranunculus sprouts from step 1 into clay or porcelain flower pots filled with culture substrate and nutrient solution; the substrate is a mixture of vermiculite, perlite, and sand mixed at a ratio of 4:1:5; the concentration of the nutrient solution is 2-5%, and its composition is: calcium chloride 500-1200mg, potassium chloride 300-350mg, ammonium phosphate 450-500mg, magnesium sulfate 500-800mg, carbon, hydrogen, oxygen, and nitrogen elements 10-15mg each, silicon element 10-15mg each, and iron, boron, manganese, copper, zinc, and molybdenum elements 2-5mg each.
3. Water and fertilizer management: Move the flower pots from step 2 into an ambient temperature of 5-20°C, water once every 3-8 days so that the substrate in the pots is moist but not waterlogged, drip-irrigate 30-50ml of nutrient solution every 2-3 days, and at the same time ensure daily light duration of 5-8h and light intensity of 400-800lx.
4. Flower forcing: When ranunculus has just produced flower buds, move the flower pots into an ambient temperature of 10-25°C, and at the same time spray ranunculus once every two days with a flower-forcing agent at a concentration of 0.5-5%, until ranunculus blooms.
5. Flowering period management: After ranunculus blooms, move it into an ambient temperature of 0-10°C. The flowering period of ranunculus is generally from April to May.
6. Disease control of ranunculus
(1) Rot
Due to adverse conditions such as heavy, clayey soil with high alkalinity, or low temperatures with excessive and prolonged water in the soil, pathogens are easily triggered, and the plant becomes infected with root rot, causing the root system to rot and turn dark brown or black, the aboveground stems and leaves gradually wilt and turn yellow, and the plant dies. The internal tissue of the affected area changes from white to gray, the outer epidermis is covered with a layer of mycelium, and the tubers gradually rot.
Solution: Before planting, the culture soil and tubers should be thoroughly disinfected, and they should be planted appropriately shallowly. In the early stage of the disease, drench the roots with 75% thiophanate-methyl 800-fold solution or 50% benlate wettable powder 1000-fold solution. For potted ranunculus, the pot can be immediately changed and the substrate replaced to control the spread of the disease.
(2) Mold
Penicillium rot mainly occurs during the tuber storage period, and also occurs from time to time during the growing period. Infected tubers appear dark brown or black. In severe cases, the surface of stored tubers is covered with a large amount of Penicillium conidia, which easily infects healthy tubers.
Solution: Before planting, strictly remove tubers carrying pathogen spores, mechanical injuries, and insect bites, then soak them in 75% thiophanate-methyl 800 or 1000-fold solution for 10 to 15 minutes, dry them, and then plant, reducing the possibility of disease occurrence.
(3) Southern blight
Southern blight is caused by infection by a fungus that forms small sclerotia, and mainly attacks the base of the plant stems. In the early stage of the disease, water-soaked, light brown, irregular lesions appear at the stem base, and then white silky mycelium is produced on the diseased area, gradually tangling into rapeseed-like sclerotia.
Solution: Spray and drench the rhizosphere soil beside the plant with 50% carbendazim wettable powder 800-fold solution to control the development of the disease. In the early stage of the disease, spray and drench the stem base of the plant and the surrounding soil with 75% chlorothalonil wettable powder 500-fold solution and 5% validamycin 1000-fold solution, which can alleviate the condition.
Ranunculus has relatively strong vitality. Its flower language means "popular," and it can generally be used to bless others. It also implies being easygoing and talkative in personality, making it a flower quite suitable for giving to friends.
Introduction to Ranunculus Cultivation: When Is the Best Time to Plant Ranunculus
Ranunculus has rich flower colors, generally mostly double or semi-double, and its flower shape is like a peony, but relatively smaller. Its leaves are like celery leaves, and because of this it is also often called celery flower. It is native to southeastern Europe and southern Asia. It was introduced from England for artificial cultivation only in 1596, so it is relatively common in gardens or as cut flowers. So how much do we know about the cultivation time? The editor has brought you knowledge about the cultivation time, and I hope you will like it.
[Growth Habits]
You should know that ranunculus is a plant that prefers cool and semi-shaded environments, and it also avoids heat. The most suitable growth temperature is around 20°C during the day and around 7-10°C at night. It fears both wetness and drought, and is best planted in well-drained, fertile, loose neutral or slightly alkaline soil. After June, the tubers enter dormancy. Ranunculus is native to western Asia centered on Turkey and southeastern Europe, so it prefers a mild climate, fresh and humid air, and a loosely shaded growing environment, but it is not tolerant of severe cold and freezing, and is even more afraid of intense summer heat and blazing sun. In most regions of China, it remains dormant in summer. For pot cultivation, it requires a sandy culture soil rich in humus, loose and fertile, with strong permeability.
[Cultivation Methods]
Light management: Ranunculus cannot tolerate strong light and also prefers semi-shaded environments. In winter it needs sufficient light. In spring, as the temperature rises and light intensity increases, it should be appropriately shaded and ventilation strengthened. Because it is a long-day plant, long-term sunlight conditions are beneficial for promoting flower bud differentiation, while early flowering and vegetative growth will also terminate early, and tubers will also form earlier.
Water management: Ranunculus is a plant that fears wetness and waterlogging, and is relatively drought-tolerant, but it should not be allowed to become excessively dry. Especially during its growing period, excessive drought will force it into dormancy and will also cause the quality of its tubers to deteriorate. We generally need to give it one thorough watering after planting, and subsequent watering should be timely and balanced, not too dry or too wet.
Fertilizer management: Before planting ranunculus, we can also choose decomposed cake fertilizer, etc., as the base fertilizer, and it should be spread evenly. After transplanting, when the plant shows obvious growth or produces new leaves, topdressing can begin.
Temperature management: Ranunculus likes a cool environment. The most suitable daytime temperature is between 15-20°C, while the nighttime temperature needs to be 1-8°C and must not be too high or too low. The temperature difference between day and night also must not be too large, otherwise the growth and development of ranunculus will be affected, leading to a decrease in the number of flowers and their quality.
Ranunculus Cultivation Techniques
Overview: Variety types and commonly used varieties. The 'Flower Valley' series is a commonly used imported excellent potted variety. 'New Paradise' is an excellent new dwarf large-flowered double-petaled line newly bred by the Potted Flower Research Institute of Dafeng City, Jiangsu Province.Morphological characteristics: Pinnate or palmately compound leaves with three deep lobes. Different growth stages and different individuals show differences in leaf color, shape, and depth of lobing. Cotyledons are elliptical, young leaves have few notches, and later true leaves gradually develop more notches. Under low winter temperatures, it forms a rosette-like clump, with leaves flat and overlapping. Underground it has fat, dark brown small tubers, multi-legged in shape, resembling dahlia tubers. It can be propagated by division, but the operation is inconvenient and the multiplication rate is also low, so apart from occasional use for asexual propagation of excellent single plants, it is rarely used in production. Differences in the size and number of small tubers reflect the nutritional level of the tuber, affecting not only the size of the plant at the early stage of tuber germination, the number of tillers, and growth vigor, but also the number of flower stems later. For pot flower cultivation, tubers are generally required to have more than 5 small tubers, and the length of the small tubers in a dry state should be more than 1cm. The size, number, weight, and shape of tubers are greatly related to management before the plant enters dormancy. If nutrient consumption is large during flowering, fertilizer and water supply is insufficient, or the temperature is too high and dormancy occurs too early, or artificial high temperature and drought cause sudden forced dormancy, the small tubers will appear uneven in length and shriveled and small. After June, the aboveground part gradually withers and the tubers enter dormancy.
Ecological habits: Ranunculus has no physiological dormancy. Harvested tubers planted at 5°C-15°C will sprout in 2-3 weeks. Dry treatment of tubers can control sprouting and allow long storage. Ranunculus tubers must be stored after being fully dried, otherwise they easily rot.
Seeds mature from May to June, about 1800 seeds per gram. The seeds are flat and wrapped in a very thin membrane. The suitable temperature for seed germination is 10°C-15°C, and they germinate in 2-3 weeks. They cannot germinate above 20°C or below 5°C.
After absorbing water, tubers cultivated at a night temperature of 10°C-12°C for 7-8 weeks can unfold 10 leaves. At this time, the growing point at the stem tip begins to swell and enters the flower bud differentiation stage, which is completed in 2-3 weeks, and after about another 10 weeks, flowering can occur.
Potted ranunculus production generally uses the sowing method, but the sowing method requires a relatively high level of cultivation to produce high-quality potted flowers (seedling plants often have problems such as insufficient nutritional levels and few flowers). Therefore, there is also the "tuber method," in which the sowing method is used to produce tubers and the tubers are used the following year to produce potted flowers. The cultivation costs and economic benefits of the two methods still need to be compared.
Growth and development conditions
Water: Ranunculus is native to Syria and Israel. Its native habitat has high temperatures and dryness in summer, and low temperatures and abundant rain from autumn to spring. Therefore, ranunculus has the habit of growing and developing in autumn and winter, flowering in spring, and going dormant in summer. Its growth process has a high demand for water. Water shortage in the early growth stage will lead to short plants, small leaves, fewer tillers in the future, underdeveloped roots, fewer flowers, small flowers, and a low double-petaled rate; water shortage in the middle stage will seriously affect flowering, with small flower stems, a short flowering period, dull colors, and leaves will also turn yellow; water shortage in the later stage will force the plant into dormancy and result in poor tuber quality. However, as a tuberous flower, too much water also carries the risk of root rot. The water supply must also be balanced and appropriate; excessive drought or waterlogging will seriously affect growth. Water imbalance can also cause tuber cracking. The general rule of water demand during its growth process is: a certain degree of water is needed in the early cultivation stage, reaching maximum at the early bolting stage, and then gradually decreasing.
Day-length response: Ranunculus is very sensitive to day-length response. When seedling plants encounter long-day conditions, they will flower early or stop growing and begin to form tubers. Although this is related to the relatively young physiological maturity age of ranunculus, the most important thing is that long-day conditions promote flower bud differentiation. Although short-day conditions can inhibit flowering, when the plant grows to a certain size, it can still carry out flower bud differentiation. This shows that ranunculus is only a relative long-day flower. Some people used cut flower varieties for experiments. The long-day treatment (4-hour interruption treatment from 22:00 to 2:00) flowered 45 days earlier than the short-day treatment (8 hours), and 41 days earlier than the natural treatment (ck). However, under long-day conditions, flower quality decreased, flower diameter became 2.5cm smaller, and flower stems increased by 2-8cm. Compared with tuber cultivation, seedling plants show a more obvious long-day response, flower earlier, and enter dormancy correspondingly earlier. The effect is more significant when the day length is more than 12 hours, but if it reaches 20 hours of lighting, they cannot flower, or flower less, with slender pedicels and a decreased double-petaled rate. Under short-day conditions, meristem activity is relatively high and lateral bud formation is promoted. Therefore, when planting ranunculus in autumn, especially for sexual propagation, planting and sowing must not be too late, so as to ensure sufficient vegetative growth before the arrival of long-day conditions in spring, thereby ensuring the quality of potted flowers (flower number, plant height, double-petaled rate).
Temperature: The minimum growth threshold temperature for ranunculus is -5°C, and the minimum growth temperature is above 5°C. Growth is fastest under conditions of a night temperature of 8°C and a day temperature of 10°C-15°C. Growth and development are poor above 20°C, and the aboveground part begins to wither above 30°C, but dry tubers can endure fairly high temperatures. Low-temperature treatment at the seedling stage has a significant effect on the growth period. Low-temperature treatment at 5°C for 4 weeks can advance flowering by 14-20 days under long-day, short-day, and natural treatment conditions. Although ranunculus does not like high temperatures, under long-term low-temperature conditions, especially when soil moisture is relatively high, root rot may also occur. During the vegetative growth period, it is advisable to control the day temperature at 15°C-20°C and the night temperature at 5°C-10°C. When the day-night temperature difference is too high, the number of flowers in the future will decrease, the double-petaled rate will decline, flower stems will become taller and weaker, and the quality of potted flowers will be seriously reduced. During the flowering period, a temperature of 13°C-15°C is suitable to extend the flowering period.
Soil environment: Ranunculus has relatively high soil requirements, and soil rich in organic matter, with good aggregate structure and the ability to maintain appropriate porosity, is best, with a pH of about 6.5.
Key points of "tuber method" potted flower production technology
Small tubers cultivated by sowing in the previous year are used as propagation material to produce potted flowers. The "tuber method" has a short production cycle, early flowering, thick and short flower stems, a high double-petaled rate, and good potted flower quality.
Tuber water absorption. Tubers are dry during storage. If the tubers absorb water quickly, most tubers will rot. If the temperature is too high when the tubers absorb water, they will also rot. Only low-temperature water absorption is the safest and most effective, so they must slowly absorb water below 5°C. The reason may be that when tubers absorb water rapidly from an extremely dry state, strong cell expansion can cause mechanical damage and physiological disorders, and latent mycelium on the tuber surface is more likely to invade during rapid water absorption. Tubers that have just absorbed water, especially under high-temperature conditions, also have very weak resistance to pathogens.
The method of low-temperature water absorption is: bury the tubers in clean coarse sand, then spray water fully; excess water will leak out from below without accumulating, and place them in a 1°C-3°C cold storage to slowly absorb water. If there is no cold storage, spread a layer of coarse sand in a cool place, insert the tubers upside down into the coarse sand, bury the sprouting parts, but leave most of the tubers exposed. Spray water frequently to ensure the substrate does not dry out. Soon the tubers will swell, and after the central buds begin to sprout and new roots grow, promptly pick them out for planting (bud length must not exceed 1cm). To prevent tuber rot, water for spraying should use lower-temperature well water or deep-well tap water, and fungicide can be added during spraying. Without lowering the ambient temperature, use a 60% shade net for shading. If conditions permit, spray cooling facilities, or a basement or air-conditioned room can be used for germination forcing. During germination forcing, prevent damage from heavy rain, pay attention to weather forecasts, and cover with film in time to avoid rain.
Planting tubers in pots. For ease of management, tubers after germination forcing are planted in 10×8cm nutrient pots for centralized management. To prevent tuber rot, the soil for potting should be disinfected according to its source. Bromomethane 4m3/can (860ml) sealed fumigation treatment for 2-3 days, then uncover the film and ventilate for 7-10 days before use. The soil for potting should be relatively moist; if too dry, add water and pile it to, and use it the next day. The planting depth is 0.8-1.0cm of soil above the top of the tuber buds. Too deep is not conducive to leaf emergence, and too shallow is not conducive to root development. Control watering before and after emergence, with the degree of maintaining pot soil moisture as the standard. After full emergence, gradually increase the amount of watering. Fertilize 2-3 times at the seedling stage, with a concentration of 0.8‰-1.0&permil.
Potting. Tuber seedlings are potted using small 5-inch clay pots or 14-16cm plastic pots. The potting soil is high-quality compost + 1/4 decomposed sawdust + 1.0kg/m345% compound fertilizer. The planting depth is level with the soil ball or slightly above it. Those originally planted deeper in pots should be planted appropriately shallower when potted, and those originally planted shallower should be planted appropriately deeper. The potting soil also must not be too dry, and water thoroughly once after planting. When potting tuber seedlings, leave a larger rim than for general flowers to prevent the root system from filling up and lifting the soil ball, causing difficulty in watering and fertilizing.
Management after potting
(1) Temperature: The most suitable growth temperature for ranunculus is 15°C-20°C during the day and 7°C-8°C at night. Under plastic greenhouse cultivation conditions, the maximum temperature in the greenhouse should not be higher than 22°C, and the minimum should not be lower than 0°C. Increasing the night temperature is beneficial for shortening the growth period, and appropriately lowering the night temperature is beneficial for compact plant shape.
(2) Light: Give as much light as possible in winter.
(3) Water: Ranunculus prefers water, so watering should be sufficient, timely, and balanced. But too much water is harmful. On the one hand, ranunculus is a bulbous flower and is not tolerant of waterlogging; on the other hand, the air humidity in the greenhouse itself is relatively high, and too much water will cause disease epidemics. Therefore, avoid the mistaken practice of watering too frequently but insufficiently each time. Instead, water thoroughly each time and water again after it dries. Between two waterings, keep the plants and the air in the greenhouse as dry as possible to achieve the purpose of controlling plant shape and controlling diseases. But the degree of dryness should be based on the pot soil surface being dry while the leaves do not obviously wilt. Excessive dryness will cause root hair death. If watering is suddenly resumed after drying, it will cause leaf yellowing, poor flowering, and tuber cracking. After bud appearance, watering should preferably be done as spot watering, and after flowering, spray watering is prohibited.
(4) Fertilization: Once a week, concentration 1.5‰-2.0‰. 46% urea, 45% water-soluble compound fertilizer (mainly urea in the early stage, mainly compound fertilizer in the later stage).
(5) Plant adjustment: Under "tuber method" cultivation, growth and development mostly occur in winter. During this period, sunlight is short and the temperature is also relatively suitable, so leggy growth generally does not occur. Pull the pots once before and after bud appearance. When pulling the pots, separate large and small plants, and separate early and late bud appearance. In the early stage of bud appearance, when flower buds grow out of the leaf cluster, spray once with 120-150ppm paclobutrazol (15% powder 8-10g/10kg) as appropriate. When bud appearance is early or late, spray in batches, and do not repeat the spray.
(6) Pest and disease control: The main diseases are sclerotinia rot and gray mold. Water reasonably, strengthen ventilation, and pull pots in time; pay attention to the cleanliness and hygiene in the greenhouse; the potted flower production site should be rotated and disinfected; diseased plants should be handled in time; in the middle and late growth stages, supplement with necessary chemical prevention, such as 46% dimethachlon, 55% chlorothalonil, 50% procymidone, etc., sprayed at 500-1000 fold. The main pest is leafminer, which occurs in early to mid-April. The nymphs feed on leaf mesophyll and can cause serious damage. Use 50% chlorpyrifos 2000-fold for control 1-2 times.
"Sowing method" potted flower production technology
The advantages of the sowing method are a short production cycle, low cost, fast propagation, and large production volume; the disadvantages are fewer flowers, late flowering and marketing, plants easily growing tall, the double-petaled rate being greatly affected by cultivation techniques, high requirements for cultivation conditions, and strict management requirements, otherwise the quality and finished product rate of potted flowers will be low. The key points of sowing method production technology are: sow early at the appropriate time, cultivate strong seedlings, pay attention to water and fertilizer management, promote early plant development and large plant development, and appropriately apply dwarfing agents to control plant height.
Seedling raising
(1) Sowing period: late August to early September.
(2) Sowing rate: 2-3g/m2.
(3) Seed treatment: To bring marketing forward, low-temperature seed soaking and germination forcing treatment is preferable. After soaking the seeds in water for a day and a night, wrap them in gauze and force germination in a constant-temperature chamber at about 15°C or in a water well. Rinse once in the morning and once in the evening each day. After rinsing, shake off excess water (the fruit coat is membranous, and when gathered together it contains a lot of water, so a washing machine can be used for dehydration). After 10 days of germination forcing, the seeds begin to move; once a small number of seeds germinate, sow immediately.
(4) Sowing: After appropriately drying the seeds in the shade, mix them with sufficient yellow sand and sow evenly.
(5) Covering thickness: Cover immediately after sowing, with a thickness of 2-3mm.
(6) Management after sowing: After sowing, place a layer of shade net flat on the bed surface and cover the frame with a layer of 60% shade net, and spray water 1-2 times a day. Germination-forced seeds emerge in about 5 days, while dry-sown seeds emerge in about 20 days. Pay attention to checking emergence and promptly remove the flat-covering shade net. The shade net on the frame can be removed in the evening after full emergence, and covered again before 8 a.m. the next day, allowing the seedlings to receive weak morning and evening light. After the heart leaf breaks, gradually extend the light exposure time. After covering the greenhouse in mid-to-late October, cultivate under full light.
After the heart leaf breaks, fertilize about once every 10 days, with a concentration of 0.5‰-1.2‰.
In the early stage of watering, pay attention to keeping the seedbed moist; in the later stage of seedling growth, pay attention to alternating dry and wet conditions to prevent disease and leggy growth.
(7) Seedling separation: Carry out when there are 3-4 true leaves. Use 10×8cm nutrient pots for seedling separation, and the planting depth should be slightly above the white part at the base of the seedling. For the soil used for seedling separation, refer to the potting soil for the "tuber method," and the quality should preferably be a little better.
When lifting seedlings, pay attention to removing seedlings with long petioles and small leaves, and seedlings with very short petioles, thick leaves, and dark green color. The former will have fewer tillers, tall stems, small flowers, and a low double-petaled rate in the future; the latter will become "dwarfs" with small plant development in the future.
(8) Management after seedling separation: Ranunculus seedlings do not easily hold soil, so after seedling separation, provide short-term shading at noon. Seedling separation mostly occurs from mid-November to mid-December. If the temperature is low, the greenhouse temperature should be appropriately raised, preferably 20°C-22°C during the day and 8°C-10°C at night (cover the second and third layers of cold protection materials earlier). After the seedlings recover, manage at normal temperature.
When the heart leaves grow obviously, it indicates that the seedlings have recovered and normal management can be carried out. The fertilizer concentration is 1‰ in the early stage, and 1.5‰-2.0‰ can be used later. The fertilizer type is mainly nitrogen fertilizer, with 2-3 applications of compound fertilizer in between. Fertilization is generally about once every 10 days.
Potting
(1) Pots used: Sowing seedlings develop into smaller plants than tuber seedlings. Large seedlings are cultivated in small 5-inch pots, and later batches of seedlings use 4.5-inch pots. The last small seedlings can only be cultivated in the original pots for tuber production. Remove the buds at bud appearance to concentrate nutrients and promote tuber enlargement. Weak seedlings and diseased seedlings should all be eliminated.
(2) Pot soil: Refer to the "tuber method," but the quality should be a little better, because the sowing method grows more slowly and the growth period is shorter.
Management after potting
Management after potting can mostly refer to the "tuber method," but in plant adjustment, attention should be paid to the characteristics of the "sowing method."
(1) To promote plant development, the first flower can be removed at bud appearance.
(2) To prevent flower stems from growing too tall, depending on the actual situation, use paclobutrazol once before the flower buds grow out of the leaf cluster but before color appears, at a concentration of 100-120ppm.
(3) Fertilization should be lighter and more frequent than in the "tuber method."
(4) When flowering, the temperature rises and light increases. Pay attention to ventilation and cooling and shade as appropriate to extend the flowering period.