How to Grow a Dawn Redwood Bonsai? Detailed Guide to Cultivation Methods and Precautions

The dawn redwood is native to China and is one of the country's key protected trees, so its care requires special attention. In particular, a bonsai made from a dawn redwood is not only highly ornamental but also serves a decorative purpose. So how should a bonsai dawn redwood be grown? What cultivation methods does it have? What precautions are there? Follow the editor below to find out.

How to Grow a Bonsai Dawn Redwood

1. Soil

The dawn redwood prefers warm and humid climate conditions and mostly grows in places with gentle terrain, deep soil layers, and moist or slightly waterlogged conditions. Therefore, when choosing soil for cultivating a dawn redwood bonsai, you should choose acidic mountain yellow soil or purple soil, mixed with breathable substrates such as peat soil.

2. Light

The dawn redwood is light-loving. Under conditions of sufficient light, its leaves are a rich, fresh green, which will give the dawn redwood a lively and vigorous appearance. Therefore, the dawn redwood bonsai can be placed outdoors to receive sufficient light, and in winter the bonsai should be moved indoors to a windowsill with scattered light.

3. Fertilizing

A dawn redwood bonsai should be moderately dwarfed, so base fertilizer can be applied before planting, and fertilizer can be applied again when the plant begins to grow. Do not fertilize too early, because fertilizing too early will cause the dawn redwood stump to suffer from “indigestion.” Note that during later care you should not apply too much fertilizer; just ensure the plant's normal growth needs are met. Applying an appropriate amount of dilute liquid fertilizer can better promote the vigorous growth of fibrous roots, branches, and leaves. Be careful not to damage the roots.

4. Watering

After planting, the dawn redwood should be watered regularly, and the principle of watering when dry and stopping when wet should be followed, with each watering done thoroughly.

Cultivation Methods and Precautions for Dawn Redwood Bonsai

I. Cultivation Methods for Dawn Redwood Bonsai

1. Use a flower pot of appropriate size

When growing a dawn redwood bonsai, you must use a flower pot of appropriate size. The pot must not be too small, otherwise its roots will be unable to grow normally, which will lead to root rot and prevent new roots from emerging. Over time, the dawn redwood will gradually die.

2. Provide timely ventilation

This plant, the dawn redwood, likes a growing environment with good ventilation. When growing a potted dawn redwood at ordinary times, be sure to place it indoors in a well-ventilated spot, and place wood under the bottom of the flower pot; do not place it directly on the ground, otherwise, due to poor ventilation, its leaves may fall off or its root system may be damaged, so that the dawn redwood in the pot cannot grow normally.

3. Pay attention to pruning the root system

When growing a potted dawn redwood at ordinary times, be sure to pay attention to pruning the root system, because this plant's root system develops especially quickly and will form a crisscrossing, dense mass in the flower pot. Each year when repotting the potted dawn redwood, you should take the plant out, remove all the rotten and aged roots from its root system, and then transplant it into a new flower pot. Only in this way can new roots be promoted and the dawn redwood grow more vigorously.

4. Water and fertilize moderately

When growing a potted dawn redwood, be sure to water and fertilize moderately. Although it is a water-loving plant, you must not overwater, and you must not let water accumulate in the flower pot, otherwise it will also affect the normal growth of the dawn redwood. In addition, this plant, the dawn redwood, has different fertilizer requirements. During ordinary care, it does not need frequent fertilizing; fertilizing once every two months is enough, and the fertilizer must be a thin liquid fertilizer.

II. Precautions

1. What should be done if the branches and trunk of a dawn redwood bonsai dry up?

Place the dawn redwood bonsai in a semi-shaded spot. If the soil is too wet, pull the plant out of the pot and put it back in the pot after the moisture has evaporated. In addition, change the soil; buy leaf mold from the flower market, and it must be fully decomposed and disinfected. Cut off about a 3 cm section of the original roots, disinfect them or treat them with rooting hormone, and then put the plant into the pot. Remove some leaves to reduce nutrient consumption. If the plant is too large, you can buy nutrient solution to supply nutrients directly.

2. The root system of a dawn redwood bonsai is crisscrossing and dense; how should it be separated?

The root system of a dawn redwood bonsai does not need pruning. According to the growth of the bonsai, repot once every 2-3 years. When repotting, combine it with root pruning; roots that are too dense or too long should be pruned. This can be considered according to the following situations. If the tree's new roots are poorly developed and the root system has not densely covered the bottom of the soil ball, then the original pot can still be used for repotting, and there is no need to prune the root system. For tree species with well-developed root systems, if the fibrous roots densely cover the bottom of the soil ball, then a slightly larger pot should be used, the dense root system should be thinned out, old roots should be removed, and a small number of new roots should be retained when repotting. For some old stump bonsai, when repotting, the roots can be appropriately raised to increase their ornamental value. Also prune away old roots and part of the root tips, and cultivate with loose, fertile soil to promote new roots.

3. What is going on when a dawn redwood bonsai drops its leaves?

Three points to note when a dawn redwood bonsai drops leaves: ① Repot reasonably. If the pot is too small, there are likely to be many dead roots, and after rotting they form pathogens, which will cause disease in the new root system and gradually kill it. ② Provide ventilation and light. The dawn redwood likes light and ventilation. Note that during high temperatures, wood must be used under the pot as a base; if it is placed on the ground, it will burn the root system, which is also a main reason for leaf drop. ③ Fertilize less and water frequently, but do not let water accumulate.

How to Prevent Pests and Diseases on Dawn Redwood

1. The coffee carpenter moth occurs 1-2 generations a year, and its larvae bore into the stems to cause damage, resulting in dead branches, preventing the plant from growing and flowering normally, or hollowing out the stem so that it breaks. The control methods are as follows:

① Cut off the damaged tender branches, and burn the dead branches in a centralized manner

② Insert a wire into the insect hole, and hook out or stab the larvae to death

③ Inject 80% dichlorvos or 40% omethoate at a 100-200 times dilution into the insect hole, and seal the insect hole with wet mud to kill the larvae

④ During the hatching period, spray 40% omethoate, or 80% dichlorvos emulsifiable concentrate at a 1000-1500 times dilution, or 50% fenitrothion emulsifiable concentrate at a 1000 times dilution

2. The rose sawfly can occur 2 generations a year, overwintering as larvae in cocoons in the soil. It has a gregarious habit, often gathering in groups of dozens on leaves to feed, and in severe cases can eat all the leaves, leaving only the thick leaf veins. Females lay eggs on branch tips, which can cause the branch tips to die. Control methods:

① Manually remove hatched larvae together with leaves

② In winter, remove cocoons to eliminate overwintering larvae

③ Spray 80% dichlorvos emulsifiable concentrate at a 1000 times dilution, or 90% trichlorfon original solution at an 800 times dilution, or 50% fenitrothion emulsifiable concentrate at a 1000-1500 times dilution, or 2.5% deltamethrin emulsifiable concentrate at a 2000-3000 times dilution

3. Leafhoppers can occur 5-6 generations a year, overwintering as adults on evergreen trees such as oriental arborvitae or in weed thickets. Nymphs or adults use their mouths to pierce and suck sap, causing pale white spots to appear on leaves. When damage is severe, the spots become patchy, or the epidermis is pierced, causing branches and leaves to wither. Control methods:

① In winter, clear away fallen

② leaves and weeds in the nursery to reduce overwintering insect sources

③ Use black lights to kill adults

④ Spray 2.5% deltamethrin wettable powder at a 2000 times dilution, or 50% fenitrothion emulsifiable concentrate at a 1000 times dilution, or 90% trichlorfon at a 1000 times dilution

4. Rust disease symptoms: a fungal disease. It mainly harms leaves and buds. It begins to develop after leaves unfold in spring, producing yellow rust spore structures on the leaf backs, petioles, and veins. After breaking through the epidermis, orange-red rust spores are released and invade the plant. By early summer it spreads extensively, forming orange-yellow or yellow-brown powdery summer spore piles, causing branches and leaves to lose green color and turn yellow. The lesions are noticeably raised, and in severe cases the leaves of the whole plant die, or flower buds shrivel and fall off. Control methods:

① Combined with pruning, remove rust-infected branches and leaves, burn them in a centralized manner or bury them deeply, to reduce sources of infection

② Apply nitrogen, phosphorus, and potassium fertilizers reasonably to prevent excessive growth, pay attention to ventilation and light transmission, do a good job of drainage, reduce temperature, and improve plant resistance

③ Spray Baume 3-4 lime sulfur mixture, or 25% triadimefon at a 1500-2000 times dilution, or 65% zineb wettable powder at a 500-600 times dilution, or 75% oxycarboxin at a 3000 times dilution

Main Values of Dawn Redwood

1. Economic

The sapwood of the dawn redwood is white, and the heartwood is brownish-red. The wood is light and soft, with straight grain and a slightly coarse structure. There is a large difference in hardness between earlywood and latewood, and it is not resistant to water and moisture. It can be used for construction, boards, papermaking, making utensils, making models, and interior decoration.

2. Landscaping

The dawn redwood is a “living fossil” tree species and an autumn foliage ornamental tree species. In landscaping, it is most suitable for row planting, and can also be planted in clusters or in patches. It can be used for greening embankments, lakesides, pond edges, courtyards, and so on, and can also be potted or planted in patches to create scenic forests, and matched with evergreen groundcover plants; it can also be planted in front of buildings or used as a street tree. The dawn redwood has a certain resistance to sulfur dioxide and is an excellent tree species for greening industrial and mining areas.

The dawn redwood likes light and is not tolerant of barren and dry conditions. It purifies the air, grows slowly, is very easy to survive, and is also easy to care for, making it very suitable to keep a potted dawn redwood bonsai at home. The above is the content compiled by the editor, and I hope it is helpful to you.