Introduction to the cultivation and cutting propagation methods of coleus flowers
Coleus is a perennial herbaceous plant native to Indonesia. It has strong adaptability and likes plenty of sunlight. So how should it be cultivated? The following text will introduce the cutting propagation method for coleus.
Preparing the cuttings
In summer or early autumn, when growth is vigorous, take cuttings from the coleus plant. Cut sections about 10 to 15 cm long from the top of the plant, taking care to cut below a leaf node - where the leaf meets the stem. After placing the cuttings in a short, clear glass container (such as a jelly jar or juice glass), add 3 or 5 cm of warm water to the container. Make sure the lowest cut leaf node must be covered by water.
Rooting stage
Place the glass on a windowsill that receives bright light but no direct sunlight, keeping the temperature between 21 and 26 degrees. Add water as needed so that it covers the lower leaf nodes. Within one to two weeks, the cuttings should begin to send out roots from these nodes. Once the roots are 1 to 3 cm long, the sections can be planted in various potting soils. Use pots with drainage holes.
Growth stage
When the new plants begin to grow, gradually move them to a brighter windowsill, such as an east- or west-facing windowsill, where they will receive sunlight for most of the day but will not be scorched by the intense midday sun. Keep the soil moist and fertilize once every two weeks until late autumn, using half-strength all-purpose plant fertilizer. Stop fertilizing in winter. When the plant grows to more than 20 cm, pinch off the tips to encourage new shoots.
Transplanting the cuttings
After winter, transplant the new plants into the ground in early summer. First place the pots in a shaded place for three to four hours, then bring them back indoors. Gradually increase their time outdoors, gradually moving them to a partially shaded spot. After about one week of hardening off, you can plant the coleus plants in the ground, spacing them 15 to 30 cm apart. If possible, plant them in rich, well-drained soil with a pH close to 7.0.
Cultivation and propagation of coleus
Coleus is a plant in the genus Coleus of the mint family, also known as painted nettle and coleus. The leaves of coleus are bright and vivid, and the leaf color is extremely varied. The leaf surface may be green, red, yellow, dark red, purple, and so on, with spots of yellow, red, purple and other colors, and the shades of color differ, appearing as irregular patches. Most coleus cultivated today are superior hybrids of various colors, hence the name hybrid coleus. Coleus is an excellent foliage plant. It can be grown in pots for viewing, can also be used in flower beds, and its branches and leaves can be used as cut flower material. It has high ornamental value.
Growth habits
Coleus is native to Indonesia. It likes warmth and cannot tolerate cold. The optimum growth temperature is 20°C to 25°C; it likes plenty of sunlight; it likes loose, fertile, well-drained soil; it likes moisture and dislikes waterlogging. It was originally a perennial herb or subshrub, but in most regions of China it cannot overwinter outdoors, so it is often grown as an annual.
Propagation
Because plug seedling raising saves seeds, is easy to manage, produces sturdy growth, has a short transplanting recovery period, a high seedling survival rate, a short production cycle, and high seedling-raising efficiency, in recent years coleus propagation has mostly used the plug seedling method. According to the propagation material, it can be divided into two types: plug sowing seedling raising and plug cutting seedling raising.
Plug sowing seedling raising method
(1) Seeds: It is best to choose seeds that are plump, highly vigorous, and have a high germination rate. Before sowing, they need to be disinfected. Place the seeds in warm water at 50°C to 60°C and stir for 20 to 30 minutes. Soak them in water for a period, skim off the shriveled seeds, then rinse them clean with clear water, filter off the moisture, and air-dry them for later use. They can also be soaked in 40% formalin solution, 0.5% potassium permanganate solution, or 0.3% to 1.0% copper sulfate solution, then rinsed, air-dried, and used.
(2) Substrate: The basic requirements for the substrate are that it is sterile, free of insect eggs, free of debris and weed seeds, and has good water retention and air permeability. Substrates such as peat soil, coconut coir, perlite, and vermiculite can be used. Peat soil and vermiculite are commonly used, mixed at a ratio of 2:1 and sifted before use. Before sowing, the seedling substrate is best disinfected once with a 600 to 1000 times dilution of carbendazim or chlorothalonil. It should be noted that inorganic fertilizer must never be mixed into the sowing substrate, otherwise it will cause failure to emerge or death after emergence.
(3) Plug trays: The specifications of plug trays include 288-cell, 200-cell, 128-cell, and 50-cell. Because coleus seeds weigh 3300 seeds per gram and the seeds are relatively small, 288-cell or 200-cell plug trays are commonly used. If used plug trays are to be reused, they must be cleaned, disinfected, and dried before use. They are commonly scrubbed or sprayed with fungicides such as a 600 times dilution of carbendazim or an 800 to 1000 times dilution of thiram, then rinsed 2 to 3 times with clear water.
(4) Sowing: First fill the cells with substrate, trying to fill each cell evenly, and press lightly so that the middle of the substrate is slightly lower than the edges. The substrate should not be filled too full; it should be slightly lower than the height of the cell so that the outline of each cell is clearly visible. The day before sowing, the substrate should be moistened to the point of just being thoroughly watered, that is, water seeps out from the bottom of the cell. When moistening, use automatic intermittent spraying or manual repeated spraying so that the water slowly penetrates the substrate. Then carefully place the seeds into the cells, 1 seed per cell, and the seed must fall in the very center of the cell. The seeds are light-loving, so no soil cover is needed after sowing. Outdoor sowing is often carried out in March to April, while greenhouse sowing is mostly carried out in spring, summer, and autumn.
(5) Watering: After sowing, spray water promptly until water seeps out from the bottom of the plug tray. In the early stage after sowing, the soil moisture can be somewhat higher to ensure the seeds have enough water to absorb and swell, but later the water should not be excessive; moist soil is sufficient.
(6) Germination promotion: After the plug tray is moved into the greenhouse to promote germination, the greenhouse should be properly shaded, and the interior should be kept in a state of high temperature and high humidity. Under conditions of 21°C to 24°C, germination occurs in 10 to 14 days. When the young shoots emerge, they can be moved out of the greenhouse.
(7) Transplanting: When the seedlings grow to the 2- to 4-leaf stage, they need to be transplanted once. When transplanting, dig up the seedlings with their roots and transplant them into shallow pots, with a density such that the leaves do not touch each other. When the seedlings grow to 6 to 8 leaves, transplant them again into small pots with a diameter of 10 cm, and keep 2 to 4 leaves and pinch off the growing tips. In July, when the seedlings are larger, change the pots once more, and add a small amount of soybean cake as base fertilizer at the bottom of the pot.
Plug cutting seedling raising method
(1) Cuttings: Choose tender shoots that are free of pests and diseases, moderately mature, and vigorous. At 1 to 0.5 cm above a leaf bud, with the cut sloping toward the bud, use a sharp knife (or scissors) to cut a section of branch about 5 to 7 cm long containing 2 or more axillary buds as the cutting.
(2) Plug trays: Plug trays measuring 54 cm long, 28 cm wide, and 5 cm high, with cell diameters of 3 cm or 2 cm and a depth of 5 cm, can be used.
(3) Substrate: Choose a loose, breathable substrate, such as peat and perlite (3:1), leaf mold and sawdust (1:1), or peat and garden soil (1:1).
(4) Cutting: Plug cuttings in the greenhouse can be carried out from March to October, while those in the open field are mostly carried out from April to September. The cutting density should be such that the leaves do not cover each other and do not affect photosynthesis. The cutting depth should be 2 cm, not too deep, so as not to affect rooting. After cutting, place the plug tray under a shade net with a shading rate of 70%, at a temperature of 25°C to 32°C, in a small environment with a gentle breeze.
(5) Watering: After cutting, determine the timing and frequency of watering according to the weather. On sunny days, spray water onto the substrate surface every 2 hours; on cloudy or rainy days, spray less or not at all, keeping the air humidity at around 90%, and be careful that waterlogging does not occur in the substrate. About 10 days after cutting, new roots grow, then gradually reduce the frequency of spraying. After half a month, transplant or set out in the field and enter normal management.
Cultivation management
Water management: Coleus has large, thin leaves, and if the soil is too dry the leaf color easily fades. Therefore, during the growth period, attention should be paid to watering and spraying the leaves, especially during the high-temperature period in summer, when watering and leaf spraying should be combined to increase air humidity. However, the potting soil must not be too wet, otherwise the plant is prone to leggy growth, resulting in overly long internodes and affecting the plant shape. Long-term waterlogging can also easily cause root rot and leaf drop. In winter, watering should be controlled, with the temperature maintained at 15°C, ensuring a proper balance of dry and wet.
Fertilizer management: Coleus likes fertilizer. After each pinching, apply cake fertilizer water or human waste once. During the growth period, apply 1 to 2 times of dilute phosphorus and potassium fertilizer, which can promote short internodes, dense branches, hard stems, and bright leaf color. Never apply excessive nitrogen fertilizer, otherwise the leaves easily become dull.
Light management: Coleus is a light-loving plant, and its leaf color is more vivid under full sun, so it is generally not shaded. However, during high temperatures in summer, direct sunlight should be avoided. High temperature and strong light will destroy the pigments, causing an increase in chlorophyll, which results in the plant's colors becoming less distinct or even turning green, affecting its ornamental value. Therefore, during high temperatures in summer, proper shading should be provided, while in other seasons it should not be shaded, because dim light will make the leaf color dull.
Temperature management: Coleus is not very cold-tolerant, and the optimum growth temperature is 20°C to 25°C. Growth is slow in winter, and the overwintering temperature should be above 15°C. Below 10°C, the leaves turn yellow and drop, and growth stops. If the winter temperature remains below 5°C for a long time, the aboveground stems and leaves will become water-soaked, and in severe cases the plant will die.
Pruning and shaping: If you want to cultivate a plant with a full shape, you should pinch off the growing tips to promote side branch growth. If you want to cultivate a tree-like shape, there is no need to pinch. After the inflorescence appears, if seeds are not being collected, it should be removed promptly to avoid consuming nutrients and affecting the plant shape. For mother plants kept for seed, reduce the number of pinchings and let them complete flowering and seed setting before winter.
How to grow coleus? Hydroponic cultivation methods and care guide for coleus
Coleus, also called coleus, painted nettle, and so on, belongs to the genus Coleus of the mint family. It is deeply loved by flower enthusiasts because of its high ornamental value. So how do you grow coleus? Below, the editor will introduce the hydroponic method and care guide for coleus.
1. Growth characteristics
Coleus is a perennial evergreen herbaceous plant with a perennial root system. It is often grown as a biennial. The plant height is 30 to 90 cm, and the whole plant is covered with soft hairs. The stem is square and has few branches. The leaves are opposite, ovate-rhombic, with pointed tips and toothed margins; the leaf surface colors include yellow, green, red, purple, and so on, with multiple colors inlaid into beautiful patterns, hence the name "coleus." The inflorescence is a panicle, with small labiate flowers in light blue, light purple, or milky white. The flowering period is summer and autumn. Coleus leaves are colorful and delicately changeable. The small labiate flowers are light blue-purple or tinged with white, and it is suitable for viewing both leaves and flowers.
2. Hydroponic method
(1) The cutting container can be a wide-mouth bottle, or a mineral water bottle with the upper part cut off and the lower part filled with clear water for use. The container must be clean, and the water must also be clean.
(2) When the main branch or a side branch that has been pinched has 4 nodes or is about 10 cm long, choose one with a thick, sturdy stem, leave only the opposite leaves at 1-2 nodes at the base, cut off the upper part, and make the cut smooth, without crushed or torn wounds. Then cut off the lowest pair of leaves on the branch, and gather every 3-5 cuttings together, aligning the bases, and tie them together with white thread for water rooting.
(3) Generally, it is best for the branch to enter the water 3-4 cm from the bottle mouth. After that, place it in a spot with diffused light, take care to change the clear water once every 2-3 days, and pay attention to topping up the water level in the bottle each day as it drops due to evaporation. Generally, under conditions of 18-25°C, white roots can be seen in 7-10 days.
(4) After rooting, a foliage-type nutrient solution can be added at 1/3 of the standard concentration, and every 5-7 days gradually increase the nutrient solution concentration to the standard concentration. As shown in the picture, this is hydroponic coleus.
3. Care guide
(1) Temperature and light
The temperature suitable for coleus growth is 15-25°C, and the safe overwintering temperature is 10°C. If it is below 5°C, frost damage will occur. Coleus likes plenty of sunlight. In summer, when temperatures are high, only a little shading is needed. Sufficient sunlight can make the leaf color more vivid.
(2) Changing water
Before coleus roots, change the water once every 2-3 days; after rooting, change the water once every 7-10 days, and pay attention to replenishing the water lost through evaporation.
(3) Fertilizing
Add nutrient solution when changing the water. When the air is dry, spray the plant frequently to keep the air and the plant moist.
(4) Pest and disease control
Hydroponic coleus is easily disturbed by pests such as scale insects, red spider mites, and whiteflies. During care, observe frequently whether the plant is being attacked by pests, and carry out manual removal promptly.
4. How can you keep coleus looking graceful in shape?
At the seedling stage of coleus, you can begin pinching according to the plant shape you want. If you want a clustered and full cylindrical shape, pinch the main stem of the seedling; if you want an upright, upward conical shape, do not pinch the main stem, but pinch the side branches multiple times; if you do not need to propagate by seed, remove the inflorescences promptly so as not to affect the plant's ornamental value.
The above is the hydroponic method and care guide for coleus compiled by the editor of Huinong Network. Have you all learned it?