Detailed Explanation of Key Hydroponic Techniques for Sago Palm Bonsai

The sago palm (Cycas revoluta) has high ornamental and economic value, is deeply loved by people in China and around the world, and is widely cultivated in China and globally. It can be used to decorate courtyards, conference halls, hotels, homes and more. In recent years, with the growing demand for eco-friendly indoor greenery decorative plants, hydroponic technology has become increasingly widespread in flower cultivation. Based on years of work in hydroponic flower product development and hydroponic technology research, the author focused on research experiments in hydroponic techniques for sago palm bonsai and achieved certain results. Hydroponically grown sago palms allow you to appreciate not only their stems, leaves, flowers and fruits, but also their continuously growing, diversely shaped root systems, adding brilliance to the ever-changing beauty of flowers; at the same time, they possess unique ornamental appeal and cleanliness, are easy to maintain, and transcend the spatial limitations of previous potted cultivation.

In order to improve the finished-product rate of hydroponic sago palm bonsai, shorten the production cycle and reduce production costs, potted sago palms of 50-80cm are used in production as mother plants to cultivate hydroponic products. They are first removed from their pots and have their roots removed, then placed in non-tissue-culture rapid propagation beds to induce rooting. After developing a well-developed adventitious root system of 3-5cm in length, the plants are floated in hydroponic beds for induction, and then 10-15cm water roots are cultivated, forming hydroponic sago palm bonsai products.

1. Non-tissue-culture rapid propagation facilities

Generally in a greenhouse or polytunnel, non-tissue-culture rapid propagation beds and hydroponic beds are built at a ratio of rooting area to hydroponic area of 1:2-4. Standardized beds require a smooth bed body that does not trap dirt, level walkways that do not accumulate water, and both the bed body and walkways smoothed with cement. The beds are built with bricks to a width of 1.2m and a length of 15m, with a bed edge height of 20-25cm, and walkways between beds generally 50-80cm. This bed design facilitates operation, management and environmental control. During construction, the following key points should be addressed:

1.1 Construction of the intelligent misting system

During the rooting process, maintaining water balance and creating a high-humidity environment are key. Scientific water supply must be based on an intelligent misting system. When environmental humidity drops, the misting system automatically activates to humidify the environment; when moisture and humidity are suitable, it automatically shuts off. The intelligent misting system mainly consists of an intelligent controller, sensors, solenoid valves, water pumps and pipes at various levels.

During production, sensors precisely detect changes in air humidity and substrate moisture, transmit the collected data to the intelligent controller for calculation and issue execution commands, opening or closing the execution components composed of solenoid valves and pressurized water pumps. These components, which use electricity as a starting signal, can achieve precise control according to computer commands. Through the misting system, optimization of air humidity, air temperature and substrate moisture can be achieved. These factors are the most important environmental factors in the rooting process, and during construction they require scientific design and precise implementation to cultivate plants with well-developed root systems.

1.2 Substrate selection for seedbeds

The substrate for the rooting bed system should follow the principles of drainage, aeration and freedom from contamination. Therefore, for sago palm rooting and seedling cultivation, coarse-grained perlite with good and stable physical and chemical properties is usually selected as the substrate to produce a perlite rooting bed (see Figure 1). Only these substrates can ensure good drainage, aeration and contamination resistance in a high-humidity environment. Soil containing organic matter should not be used.

1.3 Pipe installation and nozzle installation

During the rooting process, humidity is the most important factor. Therefore, the misting system used for humidity maintenance must achieve good and thorough atomization, without dripping or leaving dead corners. Typically, spray pipes are installed at a height of 0.7-1m above the bed surface, and nozzles are installed by drilling holes at equal intervals of 0.8-1m. PVC plastic pipes of various specifications can be selected as pipe material, and centrifugal plastic nozzles with good atomization can be selected as nozzles.

If year-round production is to be achieved, artificial heating technology needs to be combined during the cold winter season. Generally, a method combining small arch tunnel film covering for heating with air heating cable heating is adopted, which is more energy-efficient and effective. During implementation, air heating cables are laid in parallel inside the small arch tunnel. Of course, greenhouses with the conditions should preferably use hot air furnaces for large-space heating. This method consumes more energy, but once the temperature rises, stability is good.

2. Hydroponic induction facilities

The root system induced through non-tissue-culture rapid propagation is an adventitious root system with well-developed parenchyma tissue, possessing strong aquatic characteristics, laying a physiological foundation for entering the hydroponic induction bed to form aerenchyma.

The hydroponic induction bed needs to have a cement-rendered bottom that does not leak, and it suffices to reserve a drainage outlet at the bottom near the end close to the return liquid pool with a diameter equivalent to the return pipe. It is the outlet for circulating return flow and also the drainage outlet for thoroughly removing waste liquid, and should be slightly lower than the bed. After the bed is built, it should not be used immediately, especially the induction pool, because the cement-built bed has strong alkalinity; it must be soaked in water for at least 15-30d before use.

The construction of the water bed (see Figure 2) is the same as the rooting bed, except the medium is replaced with water. Water has a relatively high specific heat and can maintain temperature stability; at the same time, it is easy to create an anaerobic environment in water. In addition, floating boards are used for the plant-fixing portion to physically isolate and seal the water surface, which is more conducive to creating the desired temperature and dissolved oxygen environment.

The construction of this floating deep-flow hydroponic bed focuses on the design of the planting board and the layout of the oxygenation system. Different oxygenation systems can use different oxygenation methods. Currently, the oxygenation methods used for induction include three types: water circulation method, aeration method, and gas-liquid mixing method.

(1) Water circulation method. Water circulation oxygenation mainly utilizes the falling jet flow at the water inlet and return flow points during circulation to increase oxygen. Liquid enters at one end of the bed, with the inlet pipe raised 20-30cm above the water surface, creating a water flow drop for oxygenation; at the return point at the other end, water falls and splashes back into the reservoir tank. In addition to oxygenation, this water circulation method can also carry away root exudates, slowing the occurrence of poisoning from root exudates in some plants, and can also serve to stir and balance the nutrient solution.

(2) Aeration method. The aeration method involves pumping air bubbles into the water to increase dissolved oxygen in the water. This method is simple but not highly efficient; the amount of air from large bubbles that dissolves into water is extremely limited, but it is still a practical and easy-to-operate method. Simply lay out oxygenation sand heads at certain intervals in the hydroponic bed, then connect these oxygenation sand heads to an air pump. When oxygenation is needed, it automatically activates for bubble-type oxygenation.

(3) Gas-liquid mixing method. It is currently the most efficient oxygenation method for dissolved oxygen. The key is that it can make air or oxygen into micron-level small bubbles that dissolve into water, and can achieve supersaturated dissolved oxygen. At normal pressure and temperature, the dissolved oxygen content of water has a saturation value; once the saturation value is reached, even continuously running the oxygenation system cannot further increase dissolved oxygen. However, after adopting the gas-liquid mixing method, dissolved oxygen can be supersaturated, exceeding the saturated dissolved oxygen value at the same temperature by several times. In production, pure oxygen is commonly used. Oxygen output from a steel cylinder is depressurized and input into a gas-liquid mixing pump, causing the output oxygen to become micron-level small bubbles that dissolve into water. This method can be used for the production of super-oxygenated water or oxygen-rich water, and can bring dissolved oxygen in water to the predetermined required value in a short time, with extremely high efficiency.

Regardless of which oxygenation method is used, the key is to achieve a gradient linear decrease in dissolved oxygen value. During this decrease process, the transition from quantitative change to qualitative change is gradually achieved, and the plant also undergoes qualitative change caused by quantitative change, namely the formation of aerenchyma.

When dissolved oxygen falls below the predetermined variable, the computer automatically activates the aforementioned oxygenation system for oxygenation, and automatically shuts off when the parameter value is reached. It has the characteristics of high efficiency and accuracy, and is the best method for controlling dissolved oxygen in the root zone environment. This constitutes a hydroponic induction bed with controllable dissolved oxygen. Apart from dissolved oxygen changes caused by oxygenation methods, other influencing factors remain in a relatively stable state, making it easier to achieve digital control and gradient decrease of dissolved oxygen.

3. Sago palm hydroponic production technology

3.1 Mother plant pretreatment

Select qualified sago palm bonsai. About 7d before hydroponic production, spray the leaves with 1‰ urea (urea has the effect of being quickly absorbed by plants and promoting new root growth). The purpose of this is to keep the sago palm in good growing condition, which helps enhance its photosynthetic performance, promote nutrient accumulation within the plant, and lay a foundation for stimulating new root growth.

3.2 Rooting induction

(1) The pretreated sago palm bonsai is first removed from its pot, and the entire root system is washed clean. Take care to protect the leaves and new buds from damage during the repotting and washing process, so as not to affect future shaping and appearance.

(2) Use pruning shears to completely remove the root system, retaining only a small amount of fibrous roots at the upper part of the root base, to ensure the plant's water absorption in the early rooting stage and improve the success rate of rooting. Note that the scissors used during root pruning should be sharp, and the cuts must be decisive. Blunt blades easily cause enlargement of wounds at the root base, leading to infection; slow hands consume operating time and increase the risk of plant dehydration.

(3) Using prepared 200-fold KMnO4 solution, immerse the sago palm root base in it for 3-5s, then remove and rinse clean with water, completing disinfection and sterilization of the root base and wounds. Note that the soaking time must absolutely not be too long, because KMnO4 has strong oxidizing properties; prolonged contact can easily kill the cells at the root base, leading to the death of the entire plant.

Research on Hydroponic Techniques for Sago Palm Bonsai

How to care for flowers in spring?

Spring is the season when all things revive. In such a beautiful season, there must be many beauty-loving people who go to the flower market to buy one or two pots of their favorite flowers to decorate their beloved homes. In the spring breeze, flowers gradually stretch themselves and release the green that has been suppressed for so long. I believe it brings you not only the imaginable scene of spring's gentle breeze and splendor, but also a bit of surprise and longing every day. Although flowers are beautiful, they need care. Only under your careful nurturing can they bloom into more beautiful flowers and bring you greater rewards.

As spring returns to the earth, temperatures gradually rise, but the middle and lower reaches of the Yangtze River are still in the transition between winter and spring, in a period of alternating cold and warm, and chilly spring weather can occur from time to time. Therefore, it is necessary both to prepare cold-sensitive potted flowers for "moving out" and to strengthen the care and management of other potted flowers.

I. What flowers should be grown in spring?

Peach blossoms are in full bloom, crabapple and pear flowers compete in beauty, and white magnolia, Chaenomeles speciosa, forsythia, Jasminum mesnyi and most camellias have already burst into bloom. Spring orchid (Cymbidium goeringii), Daphne odora, Christmas cactus, winter jasmine, sasanqua camellia, wintersweet and others have successively faded. Famous camellia varieties in full bloom can be moved to a ventilated spot by the window, and at night moved outdoors to a warm, wind-sheltered place. However, when cold freezing weather occurs, spray with 800-fold New High Lipid Film solution to enhance cold resistance, and move them indoors; this can extend the flowering period.

1. Lucky bamboo

An evergreen upright shrub of the genus Dracaena in the Liliaceae family, very suitable for indoor hydroponic flowers. Lucky bamboo has emerald-green leaves, straight stems, and is round like bamboo. The leaves are ovate with pointed tips, and the leaf stalk base clasps the stem. It is an extremely shade-tolerant plant and still grows well, upright and strong, under weak light conditions. It can be placed indoors for long-term foliage appreciation without special care; as long as there is enough water, it will grow vigorously. When growing hydroponically, cut the lucky bamboo stems into small sections of more than 20cm as cuttings and insert them into water; as long as 1/3 of the cutting can be submerged in water, it can take root and survive.

2. Spider plant

A perennial evergreen herbaceous foliage flower of the Liliaceae family, with clustered, linear leaves and longitudinal yellow-white stripes along the edges or center. In summer and autumn, slender, flexible, drooping stolons emerge from between the leaves, and tender leaves and aerial roots sprout at the tips or nodes, bearing white flowers. Spider plants can be grown hydroponically indoors; they not only purify the air, but are also attractive in appearance and easy to manage. Dig out a potted spider plant, remove the soil from the roots, cut off old roots and rotten roots, keep the fibrous roots, place it in a container bottle, fill the bottle with clean water and flower nutrient solution, and let the spider plant roots grow submerged in water.

3. Asparagus fern

A perennial evergreen herbaceous flower of the genus Asparagus in the Liliaceae family. The stems are slender and weak, and the branches are fine and leaf-like, spreading horizontally. The flowers are small and white. The berries are spherical and black. After the fruit ripens, it presents a scene of dots of red amid dense green, elegant and lovely. The plant has strong shade tolerance and, placed on a bedside table or desk, is elegant and refined, making it a very good indoor flower. Asparagus fern is also an ideal material for backing cut flowers. In recent years, hydroponic asparagus fern has been successfully developed, and placing it in a room is even more elegant.

4. African daisy

A perennial herb of the Asteraceae family, with relatively large flower diameter, rich flower colors, and blooming in all four seasons. It prefers a warm, sunny and well-ventilated environment, is a semi-cold-tolerant flower, and likes fertile, loose soil. African daisy is a very good cut flower variety, lasts a long time in water, has high ornamental value, and is also good at absorbing formaldehyde.

5. Hyacinth

Also known as Dutch hyacinth, it belongs to the genus Hyacinthus in the Liliaceae family. It is a perennial herb with a spherical or flattened spherical bulb, covered outside with purple-blue or white tunics, and basal leaves that are thick, strap-shaped and lanceolate. The flower stem emerges from the center of the leaf stem, with a raceme inflorescence. The flower form is delicate and beautiful, colorful, dazzling and pleasant, with a fresh fragrance. It likes a sunny, cool and moist environment, and is suitable both for potting and hydroponics. When growing hydroponically, place its bulb in hydroponic nutrient solution; its appearance is clean and highly ornamental.

II. What main work should be done for growing flowers in spring?

1. "Moving out" preparation

From late March, when the weather gradually warms, windows can be opened during the day for several days (7 to 10 days), allowing these cold-sensitive potted flowers that have long stayed indoors to directly receive outdoor sunlight and air, so they gradually adapt to the external environment. After that, choose rainy days to move some flowers with slightly stronger cold tolerance, such as sago palm, rubber tree, jasmine, spring orchid, amaryllis, calla lily, Chinese hibiscus, cyclamen and others, outdoors to a warm place. If cold low temperatures occur at night, they should still be moved back indoors to avoid the cold, and the next day still placed outdoors.

Another "moving out" method: from late in the month, move the aforementioned cold-sensitive potted flowers outdoors for 1 to 2 hours each day, then still move them back indoors. After 5 to 7 days of moving in and out for hardening, finally choose a rainy day to place them outdoors. For Dracaena fragrans, money tree, various dieffenbachia and other plants with very poor cold resistance, it is safer to "move out" from late April to early May. For households cultivating many potted flowers, around Qingming they can be treated differently and "moved out" in batches and stages.

2. Early spring management

For potted flowers that have just been "moved out" and cold-tolerant potted flowers originally placed outdoors, before they sprout and grow, they should be pruned and reshaped in time, and repotted with soil changed. For Clivia, Hippeastrum and Epiphyllum that bloom in April and May, in addition to repotting and changing soil, they should all be given one topdressing of fertilizer and sprayed with Flower Bud Strengthening Spirit solution so that they bloom at the proper time. Winter jasmine and plum blossom should be pruned after flowering. In addition to cutting off dead branches, diseased and pest-infested branches, overly weak branches and overly dense branches, one-year-old branches should be heavily cut back leaving 2-3 nodes, which can promote vigorous new branches and dense flowering. Kumquat should undergo a relatively heavy pruning before sprouting in spring: first thin out crossing branches, inward-facing branches, diseased and pest-infested branches and dead weak branches, then prune the remaining branches according to the principle of strong branches lightly pruned and weak branches heavily pruned. Usually, thick one-year-old branches are cut back leaving 4-5 buds, and ordinary-growing branches are cut back leaving 2-3 buds. This can promote the growth of many robust spring shoots and benefit flowering. Do the repotting work for azaleas, winter jasmine, plum blossom, camellia, Daphne odora and other flowers as well as evergreen broadleaf tree stump bonsai. Potting roses at this time is most suitable, and tank-cultivated lotus is best planted in late March.

3. Propagation work

In March, cuttings can be taken for propagation of Podocarpus macrophyllus, pomegranate, Chinese hibiscus, winter jasmine, poinsettia, tamarisk, grape, ivy, silver willow, firethorn and others. Apply New High Lipid Film stock solution to the cut wounds of cuttings to prevent pathogen invasion. (Note: do not use plastic wrapping again.) In late March, poinsettia, cockscomb, balsam, moss rose, Amaranthus tricolor, Gomphrena globosa, as well as canna, dahlia, gladiolus and Clivia and other flowers can be sown or planted. Seeds can be treated by mixing with New High Lipid Film.

III. Precautions for home flower growing in spring

1. Repotting

General flowers and green plants are potted when purchased, and after bringing them home it is best to keep them in the original pot. Do not easily repot them, especially at this time, when the weather is warm at first and then cold again. Many plants have relatively deep roots, and once repotted, the roots' nutrient absorption is adversely affected, causing plant death. When purchasing, also pay attention to whether the potted flower has already been repotted when sold. Generally, soil of plants not yet repotted is relatively hard and clumpy, while soil of flowers that have already been repotted is looser. Of course, some flowers have been grown for many years, and you can choose to repot once from March to April, because the climate conditions in these two months are favorable for the survival and growth of flowers.

2. Watering

For fruit-ornamental plants such as fingered citron and kumquat, it is necessary not only to keep the potting soil moist, but also to spray water on the leaves, flower buds and fruits. Only in this way can the leaves be emerald green, the flower buds rapidly expand, and the fruits brightly colored. For purchased Cymbidium orchids, poinsettias and others cultivated in greenhouses, because the temperature and humidity in their original environment differ greatly from those at home, if the leaf surfaces are not frequently sprayed with water, the leaves often become shrunken and dry. For various bromeliad flowers such as Guzmania and Vriesea, if the room temperature is below 10-15°C, not only should watering be controlled, but also too much water should not be poured into the leaf cups, to prevent heart rot.

3. Fertilizing

For camellia, sasanqua camellia, azalea, Clivia, red plum, Cymbidium orchid and others, as long as the room temperature is not below 15°C, a compound fertilizer can be applied once about every 15 to 20 days. For tree stump bonsai and potted foliage plants that have entered dormancy, all forms of topdressing should be stopped.

4. Pruning

From March to April, for potted ornamental plants, dead branches, yellow leaves and branches and leaves infected with diseases and pests should be cut off together and destroyed. Some varieties such as rubber tree and Radermachera sinica need "topping", that is, cutting off the highest tender tip, with a cut length of 2-3cm. After cutting, the cut surface can be sealed with pot-bottom ash for disinfection.

5. Cold protection

Because it is still a time when it is warm at first and then cold again, the potted plants placed on balconies should be determined according to the lower temperature limit that different ornamental plant species can tolerate. Before a cold wave arrives, they must be moved indoors to avoid the cold, or double-layer plastic tunnels can be built directly above the plants for cold protection.

6. Pest and disease control

For scale insects, whiteflies and others appearing on potted plants, promptly wipe them off with a damp cloth; for aphids appearing on potted plants, soak tobacco scraps (or tobacco shreds) in water to kill them.

Flowers can make people feel joyful, and beautiful flowers are even more pleasing to the eye. Take good care of those flowers.

IV. Common knowledge for growing flowers in spring

1. In spring, flowers grow vigorously, evaporation is high, and nutrient consumption is high, so water and fertilizer must keep up; when the potting soil cracks, water promptly; fertilize once every week or half a month; loosen the soil before watering and fertilizing.

2. After winter, dead branches and fallen leaves should be pruned promptly. For some vine flowers, supports and tying should be added promptly to distribute branches and leaves evenly and allow light and ventilation.

3. Evergreen flowers are easiest to keep alive when repotted before leafing out. Choose an overcast day to repot or pot them.

4. Pests should be killed promptly, especially when aphids occur, they must be completely eliminated.

5. Spring is a great season for flower propagation. Flowers that bloom in summer and autumn should be sown promptly, bulbous flowers should be planted promptly, and perennial flowers should be propagated by cuttings.

V. Finally, here is a "Spring Flower Growing Rhyme" for everyone.

In early spring the greenhouse gradually warms, open windows for ventilation slowly.

Open windows at noon and close them at night, to prevent too great a temperature difference.

When potted flowers first leave the greenhouse, wait until the temperature is stable.

Spring light is gentle and helps flowers grow; shade-loving flowers also need sunlight.

When first out of the greenhouse they fear dry wind; on windy days do not forget to cover with tunnels.

When potted flowers are first watered in spring, too much water easily "overloads" and ruins them.

For sprouting, nitrogen fertilizer is suitable to add; avoid strong doses, prefer light, that is safest.

If you want potted flowers to grow well, early spring repotting is most important.

Before flowers and trees resume growth from dormancy, do not delay transplanting and repotting.

If flowers bloom in early spring, repotting should wait until the flowers fade.

Stop watering before repotting, so the potting soil holds together and is not easily broken.

When planting flowers and changing pots, properly prune old roots and fibrous roots.

When planting flowers on a sunny day, wait for the evening sun; on a cloudy day, planting flowers is most ideal.

Newly planted flowers and trees should not be fertilized, nor should they be watered heavily right away.

If the soil is too wet during the seedling recovery period, the roots easily rot and the whole plant dies.

When pruning potted plants, do not hesitate; remove all branches and leaves that "spoil the beauty."

To promote early differentiation of flower buds, stop applying nitrogen fertilizer and increase phosphorus and potassium.

Eggshells, fish scales, and chicken and duck feathers, applied after decomposition, are good for budding flowers.

During the flower-forcing season, water carefully; too wet or too dry easily causes bud drop.

Do not fertilize during the flowering period; keep the potting soil slightly moist and avoid heavy watering.

When the plant is near its bud-break period, it is the most suitable time for cuttings and grafting.

When the ground temperature is stable and there is no frost, it is just right for sowing flowers.

When sowing, cover with soil carefully, to a depth about three times that of the seed.

If you want flower seedlings to come up well, shading and moisture retention are most important.