How to grow Croton (Codiaeum variegatum)? Detailed guide to cultivation methods and precautions
Seed selection:
Before sowing, the seeds must first be selected. Whether the seeds are well chosen directly affects whether sowing will succeed.
1. It is best to use seeds harvested in the current year. The longer the seeds are stored, the lower their germination rate.
2. Choose plump seeds with no damage or deformity.
3. Choose seeds free of pests and diseases.
Germination: Soak the seeds in warm hot water (a temperature similar to face-washing water) for 12 to 24 hours, until the seeds absorb water and swell. For very common seeds that germinate easily, this step can be skipped.
Sowing: For tiny seeds that are difficult to pick up with your hands or other tools, you can moisten one end of a toothpick with water and stick the seeds one by one onto the surface of the substrate, then cover with substrate 1 cm thick. After that, place the sowing pot into water, with the water depth at 1/2 to 2/3 of the pot's height, and let the water slowly soak up from below (this method is called “pot soaking”).
For larger seeds that can be picked up with your hands or other tools, place the seeds directly into the substrate and sow them in spots at a spacing of 3×5 cm. After sowing, cover with substrate at a thickness 2 to 3 times that of the seeds. After sowing, use a sprayer or a fine-hole watering can to moisten the sowing substrate. Later, when the potting soil is slightly dry, water again, still being careful not to water too forcefully, so as not to wash the seeds out.
Management after sowing: When sowing in late autumn, early spring, or winter, if a cold wave and low temperatures occur, you can wrap the flower pot in plastic film to help keep it warm and moist. After the seedlings emerge, uncover the film promptly, and let the seedlings receive sunlight before 9:30 every morning or after 3:30 in the afternoon; otherwise, the seedlings will grow very weak and spindly. After most of the seeds have sprouted, thinning is needed as appropriate: pull out the diseased and unhealthy seedlings so that the remaining seedlings have a certain amount of space between one another. When most of the seedlings have grown 3 or more leaves, they can be transplanted.
[Cutting propagation]
Cultivation methods and precautions for Hainan Croton
Chinese scientific name: Hainan CrotonAlso known as: CrotonKingdom: PlantaeDivision: AngiospermsClass: DicotyledonsFamily: EuphorbiaceaeGenus: CodiaeumHainan Croton is an evergreen shrub or small tree, reaching 50-250 cm tall, smooth and hairless. The leaves are alternate; depending on the variety, the shape, size, and color of the leaves vary greatly. The flowers are small, unisexual and monoecious, with long racemes emerging from the upper leaf axils.1. Basic overview
Species name: Hainan Croton
Scientific name: Codiaeum variegatum var. pictum
Aliases: Golden-spotted Croton, Croton
Family and genus: Euphorbiaceae, Codiaeum
2. Morphological characteristics
Evergreen shrub or small tree, reaching 50-250 cm tall, smooth and hairless. The leaves are alternate; depending on the variety, the shape, size, and color of the leaves vary greatly. The flowers are small, unisexual and monoecious, with long racemes emerging from the upper leaf axils; male flowers are white, clustered in the bract axils; female flowers are solitary on the inflorescence axis.3. Growth habits
It likes high temperatures, high humidity, and strong light, and cannot tolerate frost or snow. The winter temperature should not be lower than 15°C. It prefers heavy, fertile soil with good water retention. It is commonly propagated by cuttings. This can be done from June to August by cutting the top tender shoots, 10 cm long, drying them, and then inserting them into a sand bed; they root 3 weeks after insertion. In summer, in addition to watering, frequent misting is needed to keep the leaf surface clean. From April to October, during the growth and development period of Croton, fertilize once every ten days. After moving indoors in winter, when temperatures are lower, control fertilizer and water, and prune and shape appropriately to maintain its graceful plant shape and color. If the room temperature is below 10°C, leaf drop will occur. Common problems include black mold, anthracnose, scale insects, and red spider mites.4. Origin and distribution
Indonesia and Pacific islands5. Artificial cultivation
Propagation by cuttings
Carried out in late spring, summer, and autumn. In China it is cultivated outdoors in South China. In winter, protection against cold is necessary; north of the Tropic of Cancer, it is grown in pots, and in autumn it must be moved indoors, with the overwintering temperature kept above 13°C. It is generally done in early spring in April, and both tender shoots and 2- to 3-year-old branches can be used as cuttings. The cutting length is 10 to 15 cm. After cutting the cuttings from the mother plant, you must wait until the milky sap at the cut is completely dry or dip the cut in charcoal powder before inserting them into a sand bed with coarse sand as the substrate; otherwise, the branches are prone to rotting. Insert the cuttings into the sand bed to a depth of about 3 to 4 cm. The seedbed temperature must be kept at 24 to 30°C and covered with plastic film to help maintain temperature and humidity. After cuttings are inserted, spray water 2 to 3 times daily. When the midday temperature is high, ventilate appropriately. They generally root after three weeks. Layering propagation: Layering is best done in summer. Place a flower pot filled with good potting soil next to the mother plant, select a longer, robustly growing branch from the mother plant, bend it over, cut and wound the bark at the bend with a knife, then bury it in the new pot's soil and secure it well, keeping the potting soil moist. After the mother plant has rooted, cut the branch connected to the mother plant in autumn and plant it. Because seed propagation generally takes 1 to 3 months to germinate, and some even take half a year to germinate, it is rarely used.Layering propagation
Select a robust branch and remove a ring of bark about 15 to 30 cm below the top shoot. The width of the wound after peeling should be about 1 cm, and the depth should only just remove the outer bark. Cut a piece of plastic film 10 to 20 cm long and 5 to 8 cm wide, place some moistened garden soil on it, and wrap the girdled area as if bandaging a wound. Tie the upper and lower ends of the film tightly, leaving the middle bulging. Roots form after about four to six weeks. After rooting, cut off the branch together with the root system, and it becomes a new plant.Potting or transplanting: When potting small seedlings or repotting large plants that have been grown for several years, first place coarse granular substrate 2 to 3 cm thick at the bottom of the pot as a drainage layer, sprinkle a layer of fully decomposed organic fertilizer on top as base fertilizer, about 1 to 2 cm thick, then cover with a thin layer of substrate about 1 to 2 cm thick, and then place the plant in, so as to separate the fertilizer from the root system and avoid burning the roots.
For the potting substrate, one of the following can be chosen: garden soil: cinder = 3:1; or garden soil: medium-coarse river sand: sawdust (mushroom residue) = 4:1:2; or one of paddy soil, pond mud, or leaf mold. After potting, water once thoroughly and keep it in a shaded environment for a week of care. When transplanting small seedlings, first dig the planting hole, sprinkle a layer of organic fertilizer at the bottom of the planting hole as base fertilizer, about 4 to 6 cm thick, then cover with a layer of soil and place the seedling in, so as to separate the fertilizer from the root system and avoid burning the roots. After placing the seedling in, backfill the soil to cover the root system, firm the soil with your foot, and water once thoroughly.
Cultivation and care
For potted Croton, repot every year in early spring in April. The potting soil should be a loose, fertile sandy loam rich in humus. The cultivation substrate is best as a mixture of 3 parts coarse peat, 3 parts leaf mold, and 2 parts sand. For indoor placement, east- or west-facing windows are ideal. The growing temperature is best at 18 to 28°C, and the winter temperature must not be lower than 10°C; otherwise, it will cause leaf drop and then death. The plant likes relatively high air humidity, so the leaves should be cleaned frequently and the foliage misted. In winter, when temperatures are low and evaporation is slight, watering should be reduced, and water again when the potting soil looks dry. The lower leaves of Croton often drop easily. Appropriate pruning and topdressing should be given in time to ensure sufficient nutrients, which can prevent leaf drop. The pests and diseases of Croton include aphids, red spider mites, scale insects, and sooty mold. For red spider mites and aphids, spray 1000-fold dimethoate; for scale insects, spray petroleum emulsion diluted 100 to 150 times; for sooty mold, wipe with clean water or spray carbendazim diluted 500 to 1000 times with water.6. Garden uses
Croton stays green all year round, and its leaf shapes and colors are extremely varied, making it an excellent foliage plant. In South China, it is often planted in clumps in courtyards or used as a hedge; in East China and North China, it is grown in pots to decorate indoor environments and placed in halls, parlors, conference venues, and other places. Croton is also a good foliage material for flower arrangements, garlands, and flower baskets.Cultivation methods and precautions for Croton and Golden-spotted Croton
Family and genus: Euphorbiaceae, Codiaeum. Flowering period: summer. Flower language: unpredictable. Use tips: suitable for care at home and in public places such as shopping malls. Home placement: can be placed on windowsills and balconies.
Light
It likes a sunny, well-lit environment and has a wide range of adaptability to light. It can grow both in semi-shade and under full sun in spring and autumn.
Temperature
Suitable growing temperature: 20-30°C
Soil
It has no strict requirements for soil, and cultivation in slightly clayey, well-drained soil is best. The potting soil can be prepared by mixing garden soil, leaf mold, and river sand in a ratio of 8:1:1.
Watering
During the growth period, watering should be sufficient, and the potting soil should be kept moist. In summer, mist the foliage frequently.
Fertilizing
Generally, a diluted decomposed cake fertilizer solution or a compound flower fertilizer containing nitrogen and phosphorus should be applied once every 1-2 weeks.
Precautions
Causes of "bare legs" in Croton and control methods: 1. Lack of nutrients. The potting soil for growing Croton is not changed for a long time, while the plant grows larger day by day. The nutrients contained in the potting soil are nearly exhausted and cannot meet the needs of the plant's continued growth. 2. Compacted potting soil. Because the potting soil is clayey, compacted, and poorly drained, water accumulates in the pot, the roots cannot get oxygen, and they begin to rot. 3. Insufficient light. Croton likes a sunny, well-lit environment; if light is insufficient, its photosynthesis will be affected. 4. Improper winter warmth measures. Croton is not cold-tolerant. In northern regions, it should be moved indoors after autumn for cold protection, and a room temperature of about 20°C should be ensured, with nighttime temperatures not lower than 15°C.