How to Make a Wintersweet Bonsai and Care Tips
Wintersweet, also known as yellow-flowered plum, thousand-branch plum, fragrant plum, etc., is a plant of the genus Chimonanthus in the family Calycanthaceae. It originated in central China, with Yanling in Henan being the most famous. It can be grown in the ground, in pots, and is especially an excellent material for making bonsai. Below, let us take a look at how to make and care for a wintersweet bonsai!
Sources of Tree Stumps for Wintersweet Bonsai
1. Sowing: The sowing time for wintersweet is in June when seeds are collected; sowing immediately after collection is best. Before sowing, soak the seeds to promote germination for 24 hours to ensure uniform seedlings and early sprouting. They germinate in 10 days, and seedlings reach 10-20 cm in height in the first year. Generally, seedling plants begin to flower after 3-4 years.
2. Layering: In spring, after girdling the base, mound layering can be done; air layering can also be done during the plum rain season (late June to mid-July).
3. Division: Division propagation of wintersweet is generally carried out in spring between February and March, when the leaf buds have not yet begun to sprout. When dividing, first dig away the soil on the side of the mother plant's roots near the offset. Use a sterilized sharp knife to cut the offset away from the mother plant's roots, forming a new plant. Then plant it, taking care to provide shade after planting and keep the soil moist. After the dog days have passed, apply liquid fertilizer once every half month. By that year it will grow vigorous branches and leaves, and it will flower after 2-3 years. This propagation method is simple and easy, with a high survival rate, a short seedling-raising period, and quick flowering.
4. Grafting: Use red-hearted wintersweet seedlings or division-propagated plants as rootstock. Yangguang Seedling Network advises using cut grafting, approach grafting or bud grafting, with cut grafting being the most commonly used. Cut grafting is carried out in March when the leaf buds begin to sprout to the size of a wheat grain; approach grafting is best in late spring and early summer from May to June; bud grafting is carried out in July-August. The time for cut grafting is around mid-March, preferably when the wintersweet leaf buds have just sprouted to the size of a rice grain. If the timing is missed and the leaf buds have grown too large or leaves have already emerged, cut grafting will then be unlikely to survive.
Potting Methods for Wintersweet Bonsai
1. Pot selection: To make a wintersweet bonsai, a purple clay pot with good permeability can be used. Yangguang Seedling Network advises that the shape of the pot can be chosen according to the specific form of the tree stump and the different styling of the bonsai. Because its flowers are wax-yellow, it is advisable to choose pots in dark colors such as reddish-brown, deep blue, and dark green to create contrast, and it is not advisable to choose light yellow pots. Although glazed porcelain pots are attractive, they have poor permeability and can easily cause root rot in wintersweet, resulting in poor growth or even death of the plant, so they can be used as outer decorative pots.
2. Potting soil: Wintersweet is not strict about soil, but sandy loam with good drainage is best. For pot cultivation, decomposed garden soil or leaf mold mixed with 20-30% rice husk ash is commonly used as the growing medium.
3. Planting: Transplanting wintersweet is mostly done in early spring, preferably around early March before and after the new buds sprout on the flower stems. Generally, it is suitable to plant at a slant to make it easier to create a dynamic form when styling. Before planting, a shaping and pruning can be carried out, and sufficient base fertilizer can be applied at the bottom of the pot when potting.
Care Techniques for Wintersweet Bonsai
1. Location: Wintersweet bonsai should be placed in a wind-sheltered, sunny spot and avoid cold wind. In summer, slight shading is needed. In winter, potted plants should be moved indoors to overwinter when the temperature is below 1°C.
2. Watering: Wintersweet is relatively drought-tolerant and is known as "the wintersweet that cannot be killed by drought," but it should not be too dry either. Normally the potting soil can be slightly dry, and watering should follow "water when dry, and water thoroughly when watering"; if not watering, then do not water, but when watering, water thoroughly. The dog days are the flower bud formation period, so water must not be lacking; water once in the morning and once in the evening. When leaves fall after autumn, the potting soil can be on the drier side, watering once every 5-7 days.
3. Fertilizing: Wintersweet likes fertilizer. From April to June, in the early stage of flower bud formation, it is suitable to apply cake fertilizer water once every 10 days. From late June to before the dog days, apply a dilute fertilizer solution combining nitrogen and phosphorus once a week to promote flower bud formation. During the dog days, apply 1-2 times, with light fertilizer. After autumn, apply just once more. When repotting, sufficient base fertilizer such as bone meal and soybean cake can be applied at the bottom of the pot.
4. Pruning: To keep wintersweet with abundant branches and flowers year after year, pruning and bud pinching are extremely important. Pruning is generally done from March to June, and stopped after August. After flowering each year, the old flowering branches should be cut short immediately, leaving only 15-20 cm at most per branch. After the new branches grow 2-3 pairs of buds, pinch off the terminal bud. Soon side branches will grow again; after they reach 10 cm, pinch the buds again, repeating this several times until the flower buds are basically formed. Also thin out various crossing branches, parallel branches, overlapping branches, opposite branches, water sprouts, and overly dense or weak branches that affect the beauty of the tree shape. There is a floral saying that "wintersweet has no shortage of branches," so wintersweet can be heavily pruned.
5. Repotting: Wintersweet bonsai should be repotted once every 1-2 years, preferably in late winter or early spring after the flowers fade. Before repotting, the buds that have already sprouted can first be removed; after about 5 days, when the latent buds begin to swell, transplant. When repotting, remove 1/3 of the old soil, cut off rotten roots and dead roots, and trim away overly long old roots. Replace with frozen-crumbled pond mud or humus-rich leaf mold, mixed with an appropriate amount of rice husk ash and sandy soil.
6. Pest and disease control: Wintersweet has relatively strong resistance to pests and diseases. Occasionally there are pests such as slug moths, giant bagworms, aphids, and scale insects, which can be controlled by spraying 80% dichlorvos at 1500 times dilution or 90% crystalline trichlorfon at 1000-1500 times dilution.
Watering Precautions for Wintersweet Bonsai
1. Weather conditions: Water frequently on sunny days, pay attention to drainage on heavy rainy days, and on light rainy days the water should still be watered thoroughly.
2. Seasonal changes: Summers are hot, so water promptly, once each in the morning and evening. Spring and autumn have more rain, so water appropriately according to conditions. In winter during flowering, watering at noon is suitable.
3. Soil type: Clay soil has strong water retention, humus soil is medium, and sandy soil loses water easily; all should be noted.
4. Pot size, depth, texture, drainage holes, etc.: If the pot is small and shallow, ceramic, dark-colored, and the drainage holes are unobstructed, it dries most easily. Conversely, water retention is stronger.
5. Watering with rainwater, well water, tap water, river or pond water: Note that the water temperature should be the same as or close to the potting soil temperature, and also note that the water should not contain acid or alkali.
6. Judging whether the potting soil is dry or wet: This can be judged by leaf color, whether the leaves droop, and the color of the potting soil.
Watering Methods for Wintersweet Bonsai
1. Watering on leaves: For small areas use a watering can; for large areas sprinkler irrigation equipment can be used.
2. Root watering: For small areas use a bucket and ladle; for large areas use a hose.
3. Drip irrigation: Find a thin water pipe that can control water flow, such as a disposable infusion tube used in hospitals. Place the bucket higher than the flower pot so the pipe produces siphon action (or make a small hole in the bottom of the bucket), control the number of drops; generally 20 drops count as one leaf. Water a fixed amount each day; automated management is feasible for large areas.
4. Immersion watering: Immerse the bonsai together with the pot in water, take it out after it has absorbed water thoroughly. This can be used for the first watering after potting and for daily watering of miniature bonsai.